CIRCULAR No 25/2016/TT-BCT REGULATIONS ON ELECTRICITY TRANSMISSION SYSTEM

11 April, 2017
THE MINISTRY OF INDUSTRY AND TRADE

——–

SOCIALIST REPUBLIC OF VIETNAM

Independence – Freedom – Happiness 

—————-

No 25/2016/TT-BCT Hanoi, November 30, 2016

 

CIRCULAR

REGULATIONS ON ELECTRICITY TRANSMISSION SYSTEM

Pursuant to the Government’s Decree No. 95/2012/ND-CP dated November 12, 2012, defining the functions, tasks, powers and organizational structure of the Ministry of Industry and Trade;

Pursuant to the Law on Electricity dated December 03, 2004 and the Law on Amendments to a number of articles of the Law on Electricity;

Pursuant to the Government’s Decree No. 137/2013/ND-CP dated October 21, 2013 detailing the implementation of a number of articles of the Law on Electricity and the Law on Amendments to the Law on Electricity;

At the request of general director of Electricity Regulatory Authority,

The Minister of Industry and Trade promulgates the Circular stipulating electricity transmission system.

Chapter I

GENERAL PROVISIONS

Article 1. Governing scope

This Circular stipulates:

Article 2. Regulated entities

a) Transmission network operator;

b) Electricity system and market operator;

c) Electricity wholesalers;

d) Electricity distribution units;

dd) Electricity retailers;

e) Generating units;

g) Electricity customers receiving electricity from transmission grid (hereinafter referred to as “electricity customers”);

h) Vietnam Electricity;

i) Other organizations, individuals.

Article 3. Interpretation of terms

In this Circular, some terms are construed as follows:

  1. AGC (Automatic Generation Control) is an automatic equipment system for adjusting active power of generating sets to maintain stability of electricity systemfrequencywithin permissible scope according to operating principles of generating sets.
  2. Electricity system security is the ability of the system to supply power to meet demands for loads at a certain point of time or for a specified period with account taken of electricity system obligations.
  3. AVR (Automatic Voltage Regulator) is a system used to control terminal voltage of generating sets through the impact on the excitation system of the generating set to ensure terminal voltage of the generating set within permissible limits.
  4. Voltage level is one of nominal voltage values of a system, including:

a) Low voltage: nominal voltage level to 01 kV;

b) Medium voltage: nominal voltage level over 01 kV to 35 kV;

c) High voltage: nominal voltage level over 35 kV to 220 kV;

d) Ultra- high voltage: nominal voltage level over 220 kV.

  1. Dispatching level with control authority (hereinafter referred to as “the dispatch level”) is a dispatching level that has the right to direct and dispatch the electricity system under the dispatching hierarchy prescribed in the Dispatch Procedure of national electricity system promulgated by the Ministry of Industry and Trade.
  2. Available capacity of a generating set is the maximum generating capacity of the generating set for a specified period of time.
  3. Governor deadband is a frequency band within which any change of electricity system frequency shall not result in reactions or impacts of the governor for adjusting primary frequency.
  4. Spinning reserve is the ability of a generating set operating in the national electricity systemto increase or decrease generating capacity to restoreelectricity system frequency to permissible scope after a single fault and restore reserve capacity of frequency control.
  5. Primary frequency adjustment is the process of adjusting electricity systemfrequency immediately by a large number of generating sets equipped with a governor.
  6. Secondary frequency adjustment is the adjustment process following the primary frequency adjustment carried out through the impact of AGC system on some generating sets specified in the system or load shedding system under the frequency or dispatching instructions
  7. Electricity system dispatching is activities of directing and controlling the process of power generation, transmission and distribution in the national electricity system according to the defined procedures, technical regulations and operation modes.
  8. Electricity wholesaler is the electricity unit that is granted the operation licence in electricity wholesaling. According to level of competitive electricity market, an electricity wholesaler shall be one of the following units:

a) Electric Power Trading Company;

b) Power Corporations;

c) Other electricity wholesalers which are established according to individual levels of competitive electricity market.

  1. Generating unit is an electricity unit which is granted the operation licence in power generation, possesses one or several power plants connected to the transmission grid or a power plant of over 30 MW in installed capacity connected to distribution grid.
  2. Electricity distributor means the electricity unit that is granted the operation licence in electricity distribution, including:

a) Power Corporations;

b) Electricity companies of provinces, central-affiliated cities (hereinafter referred to as “provincial electricity companies”) affiliated to Power Corporations.

  1. Electricity retailer is an electricity unit that is granted the operation licence in electricity retailing.
  2. Transmission network operator is the electricity unit that is granted the operation licence in electricity transmission responsible for management and operation of national transmission grid.
  3. Electricity system and market operator (the national electricity system dispatch center) is the unit responsible for directing and controlling the process of power generation, transmission and distribution in the national electricity system and conducting transactions in electricity market.
  4. Reliability of a protection system includes:

a) Impact reliability of the protection system is the factor indicating ability of the protection system to work properly on an incident within the determined scope of protection;

b) Non-impact reliability of the protection system is the factor indicating ability of the protection system to avoid malfunctioning at the normal operation mode or any incident arising beyond the determined scope of protection.

  1. Governor is a device used to regulate rotating speed of the turbine of a generating set according to frequency changes to restore frequency to nominal electricity system frequency.
  2. EMS (Energy Management System) is an energy management software system to optimize operation of the electricity system.
  3. DCS (Distributed Control System) is a system of control equipment in a power plantor power station connected to the network on the principle of distributed control to increase reliability and restrict effects caused by breakdown of control elements in the power plant or power station.
  4. Electricity system is a system of generating equipment, electricity network and utilities connected to each other.
  5. The national electricity system is an electricity system which is managed in a uniform manner across the country.
  6. Electricity transmission system is an electricity system including a transmission grid and power plants connected to the transmission grid.
  7. SCADA (Supervisory Control and Data Acquisition) is a data collection system serving monitoring, control and operation of the electricity system.
  8. Earth-fault factor is the ratio between the voltage on a healthy phase during a fault and value of voltage of such phase before the fault (in case of single or double phase to ground fault).
  9. Synchronization is the act of connecting generating sets to the electricity system or two parts of the electricity system together according to synchronization conditions prescribed in the operating procedure in the national electricity system issued by the Ministry of Industry and Trade.
  10. Black start capability is the ability of a power plant to restore at least one generating set to operation from the state of complete stop and synchronize to the electrical grid without relying on transmission network in the area.
  11. Black start is the process of restoring all or part of an electricity systemto operation from the state of wholly or partial loss of power by using generating sets with black start capability.
  12. Customers using transmission grid are organizations and/or individuals possessing electrical equipment, electrical grid to connect to transmission grid, including:

a) Generating units;

b) Electricity distribution units receiving electricity direct from transmission grid;

c) Electricity retailers receiving electricity direct from transmission grid;

d) Electricity customers.

  1. Dispatch instruction is an order of commanding and controlling operation mode of an electricity system in real time.
  2. Electrical grid is a system of transmission lines, power station and utilities for power transmission.
  3. Distribution grid is a part of an electrical grid including transmission lines and power stations of up to 110 kV.
  4. Transmission grid is a part of an electrical grid including transmission lines and power stations of over 110 kV.
  5. Short-term flicker perceptibility (Pst) is a value measured for ten minutes by a flicker meter of IEC868 standard.
  6. Long-term flicker perceptibility (Plt) is a value calculated from 12 measurement resultsof short-term perceptibility for about two hours in following formula:
  7. Year N is the current year of operating an electricity system, calculated according to calendar year.
  8. Typical day is a day that has the typical day of consumption of loads as prescribed in the contents, methods and procedure for electrical load research issued by the Ministry of Industry and Trade. Typical days include typical working days, weekends, holidays (if any) of years, months and weeks.
  9. Outage or reduction of power supply according to plan is the suspension of power supply to carry out the plan for maintenance, repairs, overhaul and installation of electrical works; regulation and restriction of loads in case of a shortage according to the plan as informed by the electricity system and market operator.
  10. Thermo-electric plant is a power plant operating on the principle of thermal to electrical energy conversion including biomass, biogas and solid waste power plants.
  11. Regulations on competitive electricity market operation are the regulations issued by the Ministry of Industry and Trade and also the responsibility of the units in the electricity market by level.
  12. Load shedding is the process of cutting loads from electricity systemin case of incident or lack of electricity system security, carried out through an automatic load shedding system or dispatch instruction.
  13. Breakdown is an event or one or several equipment in the electricity system causing a disruption of power supply or affecting safe and stable supply of power to the national electricity system.
  14. Single fault is a breakdown occurring in a single component of an electricity transmission system as the electricity system is in normal operationmode.
  15. Multi fault is a breakdown occurring in at least two components of an electricity transmission system at the same time.
  16. Serious fault is an breakdown causing extensive loss of power on the entire transmission grid, or fire & explosion which damages people and property.
  17. Electricity system split is a situation in which the national electricity system is separated into disconnected small electricity systems by a fault.
  18. RTU/Gateway (Remote Terminal Unit/Gateway) is a device placed at a power station or power plant serving collection and transmission of data to SCADA system of the electricity system dispatch center or control center.
  19. PSS (Power System Stabilizer) is a device added to the automatic voltage regulator to decrease voltage fluctuation in the electricity system.
  20. Time of starting is a minimum period of time needed to start a generating set from the time the generating unit receives the starting order from the electricity system and market operator to the time the generating set is synchronized into the national electricity system.
  21. N-1 criterion is a criterion for planning, design, investment, construction and operation of an electricity system that ensures the electricity system operates normally in accordance with the operating standards, permissible operating limits when a breakdown occurs in the system or a component is taken from the system for maintenance and repairs.
  22. IEC standards are electrotechnical standards issued by the International Electrotechnical Commission.
  23.  Automatic under-frequency load shedding is the act of cutting loads by frequency relays when frequency or frequency slope of the electricity system drops below permissible limit.
  24. Power station is a substation, switching station or compensation station.
  25. Control center is a center equipped with information technology and telecommunications infrastructure system to remotely monitor and control a group of power plants, power stations or switchgearson the electrical grid.
  26. pu is a per-unit system expressing the ratio between actual value and rated value.

Chapter II

REQUIREMENTS FOR OPERATION OF ELECTRICITY TRANSMISSION SYSTEM

Article 4. Frequency

Table 1

Permissible frequency band fluctuations and time for restoration of electricity system to normal operation at other operation modes of the national electricity system

Operation mode Permissible frequency band fluctuations Time of restoration since the time of fault (effective as of January 01, 2018)
Unstable status (reset mode) Restoration to normal operation mode
Single fault 49 Hz ÷ 51 Hz Two minutes to bring the frequency to range 49.5 Hz ÷ 50.5 Hz Five minutes to bring the frequency to range 49.8 Hz ÷ 50.2 Hz
Multi fault, serious fault or extreme emergency mode Ten seconds to bring the frequency to range 49 Hz ÷ 51 Hz Ten minutes to bring the frequency to range 49.8 Hz ÷ 50.2 Hz

 

Five minutes to bring the frequency to range 49.5 Hz ÷ 50.5 Hz

Table 2

Permissible frequency band and acceptable number of beyond-the-limit times in case of multi fault, serious fault or extreme emergency mode

Permissible frequency band (Hz)

(“f” is electricity system frequency)

Acceptable number of beyond-the-limit times

(from the beginning of the cycle)

52 ≥ f ≥ 51.25 Seven times a year
50 times a year
60 times a year
12 times a year
48 ≥ f ≥ 47.5 Biennial

Article 5. Stabilization of electricity system

a) Transient stability is the ability of generating sets in the electricity system to maintain consistent operational state when subjected to major disturbances.

b) Small signal stability is the ability of generating sets in the electricity system to maintain consistent operational state when subjected to small disturbances;

c) Dynamic voltage stability is the ability of an electricity system to maintain steady voltage at all buses when subjected to major disturbances.

d) Steady state voltage stability is the ability of an electricity system to maintain steady voltage at all buses when subjected to small disturbances.

dd) Frequency stability is the ability of an electricity system to maintain steady frequency when disturbances have caused loss of load-generation balance.

  1. is a phenomenon in which the resonant frequency of the turbine shaft coincides with electricity system frequency resulting in torsional stress on the turbine shaft.

Table 3

Electricity system stability standards

Type of stability Stability standards
Transient stability Rotor angle not in excess of 120 degrees

Within 20 seconds after the fault is cleared, rotor angle fluctuation must be stamped out.

Small signal stability Damping ratio should not be less than 5%.
Dynamic voltage stability Within five seconds after the fault is cleared, at least 75% of the voltage must be restored.
Steady state voltage stability The electricity system must a reserve capacity of at least 5% in case a component is taken from the system (N-1).
Frequency stability The electricity system must meet frequency stability standards as prescribed in Clause 1, Article 4 herein.

Article 6. Voltage

Table 4

Voltage at busbars on transmission grid

Voltage level Operation mode
Normal operation Single fault
500 kV 475 ÷ 525 450 ÷ 550
220 kV 209 ÷ 242 198 ÷ 242

Article 7. Phase balance

In normal operation mode, negative sequence voltage components are not allowed to exceed 3% of nominal voltage on transmission grid.

Article 8. Harmonics

Article 9. Flicker perceptibility

Table 5

Flicker perceptibility

Voltage level Plt95% Pst95%
220 kV, 500 kV

Where: Plt95%, Pst95%: Threshold value of Plt, Pst respectively.

Article 10. Voltage fluctuation

Article 11. Neutral grounding

Article 12. Short-circuit current and fault clearing time

Table 6

Permissible maximum value of short-circuit current and fault clearing time by main protection

Voltage level

 

Permissible maximum short-circuit current (kA) Maximum fault clearing time by main protection (ms) Minimum time of withstandibility of equipment (s)
Effective up to December 31, 2017 Effective as of January 01, 2018
500 kV 50 80 03 01
220 kV 50 100 03 01
  1. d’’-%) and short-circuit reactance of a terminal transformer (Uk-%) according to the per-unit system pu is not allowed to be less than 40%.

If the aforesaid requirements cannot be met, the investor shall be responsible for installing further reactance so that total value of Xd’’, Uk and electrical reactance according to the per-unit system is not less than 40%.

Article 13. Earth fault factor

Earth fault factor of a transmission grid at all voltage levels is not allowed to exceed 1.4.

Article 14. Reliability of transmission grid

a) Outage or reduction of power supply due to lack of power from national electricity system

b) Outage or reduction of power supply due to force majeure events.

Where:

– kkccd: Percentage of electrical production not supplied in a year by a transmission grid;

– Ti: Time of outage or reduction of power supply lasting over one minute at time I is determined as the period from the time of outage or reduction to the time power supply is restored (hour);

– Pi: Average load power suspended, reduced at time i (kW);

– n: Number of times of outage or reduction of power supply in a year;

– Att: Total electrical production transmitted through a transmission grid in a year (kWh).

Article 15. Loss of power on transmission grid

∆A = Attreceived – Attdelivered
Attreceived

Where:

– ΔA: Annual loss of power on a transmission grid;

– Attreceived: Total electrical production transmitted to the transmission grid in a year is the production received by all the customers using transmission grid at connection points plus total electrical production imported through the transmission grid;

– Attdelivered:Total electrical production delivered from the transmission grid in a year is the production the electricity distribution units and electricity customers receive from connection points plus total electrical production exported through the transmission grid;

Chapter III

LOAD FORECASTING FOR NATIONAL ELECTRICITY SYSTEM

Article 16. General provisions on load forecasting for national electricity system

a) The electricity system and market operator shall make forecasts on loads for the national electricity system, electricity systems in the Northern, Central and Southern Vietnam and connection points.

b) Electricity distribution units, electricity retailers and electricity customers shall provide load forecasts to the electricity system and market operator including forecasts on demand for loads of the entire unit and individual 110 kV transformers

c) Electricity wholesalers shall provide forecasts on exportation and importation of electricity to the electricity system and market operator including forecasts on general demand and demands of connection points serving exportation and importation of electricity.

Article 17. Annual load forecasting

a) Monthly load forecasts concerning electrical energy, maximum capacity, typical daily diagrams in a 30-minute cycle for 104 weeks provided by electricity distribution units, electricity retailers and electricity customers;

b) Monthly export, import forecasts concerning electrical energy, maximum capacity, typical daily diagrams in a 30-minute cycle for 104 weeks provided by electricity wholesalers.

a) Economic growth (GDP) for the next two years officially published by competent agencies;

b) Annual load forecasts and load factor under approved electricity development master plan;

c) Statistical figures on capacity, electrical energy consumed, exported and imported at least for at the last five years by electricity distribution units, electricity retailers, electricity wholesalers and electricity customers;

d) Solutions and targets of the plan for energy saving and demand management;

dd) Other necessary information.

a) Before August 01 annually, electricity distribution units, electricity retailers, electricity wholesalers and electricity customers shall provide results of annual load forecasting to the electricity system and market operator as prescribed in Clause 2, this Article.

If the figures provided by electricity distribution units, electricity retailers, electricity wholesalers and electricity customers are inaccurate or inadequate according to the prescribed time limit, the electricity system and market operator shall rely on last year’s figures to make forecasts on loads for the national electricity system.

b) Before September 01 annually, based on the figures provided by relevant units, the electricity system and market operator shall be responsible for completing and publishing results of annual load forecasting on its website as prescribed in Clause 4, this Article.

Article 18. Monthly load forecasting

a) Weekly load forecasts concerning electrical energy, maximum capacity, typical daily diagrams in a 30-minute cycle every week provided by electricity distribution units, electrical retailers and electricity customers;

b) Weekly export, import forecasts concerning electrical energy, maximum capacity, typical daily diagrams in a 30-minute cycle every week provided by electricity wholesalers.

a) Results of monthly load forecasting in the published annual load forecasting;

b) Statistical figures on capacity, consumed, exported and imported electrical energy, maximum loads in daytime and nighttime for the month year-on-year and the last three months provided by electricity distribution units, electricity retailers, electricity wholesalers and electricity customers;

c) Events that may cause major changes to demand for loads and other necessary information.

a) Before 20th every month, electricity distribution units, electricity retailers, electricity wholesalers and electricity customers shall provide monthly load forecasts to the electricity system and market operator as prescribed in Clause 2, this Article.

If the figures provided by electricity distribution units, electricity retailers, electricity wholesalers and electricity customers are inaccurate or inadequate according to the prescribed time limit, the electricity system and market operator shall rely on last month’s figures or results of annual load forecasting to make forecasts on loads for national electricity system.

b) Before the last seven days every month, based on the figures provided by relevant units, the electricity system and market operator shall be responsible for completing and publishing results of month loading forecasting on its website as prescribed in Clause 4, this Article.

Article 19. Weekly load forecasting

a) Results of weekly load forecasting in the published monthly load forecasting;

b) Statistical figures on capacity, consumed electrical energy, maximum loads in daytime and nighttime for the last four months provided by electricity distribution units, electricity retailers, electricity wholesalers and electricity customers;

c) Daily weather forecasts for the next two weeks, public holidays, Tet holidays and events that may cause major changes to demand for loads.

a) Before 10:00 every Tuesday, electricity distribution units, electricity retailers, electricity wholesalers and electricity customers shall provide weekly load forecasts to the electricity system and market operator as prescribed in Clause 2, this Article.

If the figures provided by electricity distribution units, electricity retailers, electricity wholesalers and electricity customers are inaccurate or inadequate according to the prescribed time limit, the electricity system and market operator shall rely on last week’s figures or results of monthly load forecasting to make forecasts on loads for national electricity system.

b) Before 15:00 every Thursday, based on the figures provided by relevant units, the electricity system and market operator shall be responsible for completing and publishing results of weekly load forecasting on its website as prescribed in Clause 4, this Article.

Article 20. Daily load forecasting

a) Results of daily load forecasting in the published monthly load forecasting;

b) Figures on capacity, electrical energy of the electricity system of the last seven days or the holidays, Tet holidays of last year if the figures fall within public holidays, Tet holidays;

c) Weather forecasts of the next two days and other necessary information.

Article 21. Load forecasting in a electricity market transaction cycle

a) Results of load forecasting from the published daily load forecasting and the electricity market transaction cycle previously published;

b) Figures on capacity, electrical energy of the same period of last week;

c) Weather forecasts;

dd) Other necessary information.

a) Capacity and production of the national electricity system and regional electricity systems in a 30-minute cycle of the next transaction cycle and eight cycles thereafter;

b) Capacity and production at each point connecting the transmission grid and distribution grid in a 30-minute cycle of the next transaction cycle and eight cycles thereafter.

Chapter IV

TRANSMISSION GRID DEVELOPMENT PLAN

Article 22. General principle

a) Published annual load forecasting plans;

b) Approved national electricity development plans, provincial electricity development planning and signed connection agreements;

c) Requirements for operation of the electricity system prescribed in Chapter II and technical requirements of connection points prescribed in Chapter V herein;

d) Demand for loads and requirements for electricity system and market operation; ensuring the national electricity transmission system operates in a safe, reliable and stable manner.

Article 23. Content of transmission grid development plan

The transmission grid development plan includes following subject matters:

Article 24. Responsibility for supplying information serving formulation of transmission grid development plan

a) Lists of new power plants planned to be connected to the transmission grid in the next year with account taken of two years thereafter, progress of investment and connection, and expected date of operation of such power plants.

b) Main parameters of power plants shall be connected to the electricity transmission system and information about connection points are stipulated in Annex 1B enclosed herewith;

c) Changes related to connection to existing power plants in the next year with account taken of two years thereafter.

a) Lists of connection points in the next year with account taken of the year thereafter; lists of transmission grid projects to be invested and constructed;

b) Planned progress of energizing new connection points;

c) Maximum load capacity at new connection points and information about connection are specified in Annex 1C enclosed herewith;

d) Expected proposals for changes to existing connection points in the next year with account taken of the year thereafter.

a) Results of annual load forecasting as prescribed in Article 17 herein;

b) Expected demand for ancillary services in next year with account taken of the year thereafter;

c) Plan for mobilization of power supplies in the next year with account taken of the year thereafter.

a) Exported, imported capacity and electrical energy;

b) Progress of putting new power generation projects into operation in the next year with account take of two years thereafter.

Article 25. Procedures for formulation, approval and public announcement of transmission grid development plans

  1. to Electricity Regulatory Authority.

Chapter V

CONNECTION TO TRANSMISSION GRID

Section 1. GENERAL PRINCIPLE

Article 26. Connection point

a) Regarding overhead lines, connection points are the end points of the suspension string for outgoing feeders connected to the disconnect switches of the substation or distribution area of the power plant.

b) Regarding underground lines, connection points are the cosse of disconnector insulators on the outgoing side of the substation or distribution area of the power plant.

Article 27. Borders of assets and operation management

Article 28. General requirements

a) Position of connection point;

b) Technical information related to connection point;

c) Progress of connection;

d) Responsibility for investment and operation management;

dd) Terms and conditions of the connection agreement.

a) Customer’s electrical equipment, grids fail to meet operational and technical requirements prescribed herein and other relevant technical regulations;

b) Proposals for connection are inconsistent with the approved electricity development planning.

a) Be conformable with regulations, international agreements and commitments of which Vietnam is a signatory;

b) An agreement between relevant parties must be reached to meet all the technical requirements and technical regulations on each country’s electricity system and ensure that the operation of the electrical grids is safe, reliable and stable.

Section 2. GENERAL TECHNICAL REQUIREMENTS FOR EQUIPMENT CONNECTING TO TRANSMISSION GRID

Article 29. Requirements for connecting equipment

Article 30. Requirements for protective relay system

a) Power plants must be equipped with synchronization system;

b) Power plants must be equipped with a GPS.

c) Power plants with total installed capacity from 300 MW and on must be equipped with a phasor measurement unit (PMU) and a GPS. Power plants with total installed capacity less than 300 MW, equipment of PMU must follow calculations and requirements of the electricity system and market operator;

d) The transmission network operator and customer using transmission grid other than generating units shall be responsible for installing a GPS, PMU according to requirements of the dispatch level, ensuring compatible, reliable and stable connection to the GPS and PMU located at the electricity system and market operator. The dispatch level shall be responsible for integrating the GPS and PMU of the transmission network operator and customer using transmission grid to the system located at the dispatch level;

dd) During operation, in case of upgrading or changing the GPS and PMU, the transmission network operator and customer using transmission grid shall be responsible for making notifications and entering negotiations with the dispatch level before implementation;

e) The transmission lines from 220 kV and over connecting to generating sets or distribution area of the power plant must be equipped with two independent communication channels serving transmission of signals of protective relay between two ends of lines (transmission time no more than 20 ms);

g) Electricity customers shall be responsible for investing and installing low-frequency relays within scope of automatic load shedding management according to calculations and requirements of the dispatch level.

Article 31. Requirements for information system

The customer may negotiate an agreement for use of information system of the transmission network operator or other suppliers to connect to the information system of the dispatch level to ensure continuous and reliable communication serving electricity system and market operation.

Article 32. Requirements for connection of SCADA system

Article 33. Neutral grounding in transformers

Neutral grounding in transformers must ensure value of earth fault factor does not exceed the value prescribed in Article 13 herein.

Article 34. Power factor

a) Rated reactive power and adjustment range;

b) Principle of reactive power adjustment.

Article 35. Load fluctuation

The speed of changing power consumption by electricity customers in a minute is not allowed to exceed 10% of power consumption in normal operation mode unless the electricity customer adjusts demand as requested or under an agreement with the electricity system and market operator.

Article 36. Automatic frequency load shedding system

a) Reliability not less than 99%;

b) Any unsuccessful load shedding must not affect operation of the entire electricity system.

c) Load shedding procedures and amount of shed power must be in compliance with level of distribution by the dispatch level and must not be changed in any case without consent of the dispatch level.

Article 37. Requirements of Control Center

a) Monitoring, control and information systems installed in the Control Center must be equipped to ensure safe and reliable operation of power plants, substations;

b) The Control Center’s monitoring and control systems must be technically compatible and ensure stable, reliable and continuous connection of power plants, substations and switchgears to SCADA system of the dispatch level;

c) The Control Center must have a backup power supply to ensure normal operation in case of loss of power from the national electricity system.

– There are two independent data transmission lines to be connected to the information system of the dispatch level. If multiple dispatching levels with control authority exist, an information sharing method must be agreed by all the dispatching levels;

– There are two data transmission lines to be connected to the control and information system of power plants, substations remotely controlled by the Control Center;

– Means of communications serving dispatching and operation include direct communication channel, telephone, facsimile and computer network.

b) Requirements for connection to SCADA system

– There are two ports connecting directly, simultaneously and independently to SCADA system of the dispatch level. If multiple dispatching levels with control authority exist, a common information sharing method must be agreed by all the dispatching levels;

– There are ports connecting to RTU/Gateway, control system of power plants, substations and switchgears on the electrical grid remotely controlled by the Control Center.

c) The Control Center must install a monitoring screen connected to the surveillance camera at power plants, substations and switchgears on the electrical grid.

Section 3. TECHNICAL REQUIREMENTS FOR CONNECTION TO HYDRO POWER PLANTS AND THERMO POWER PLANTS

Article 38. Requirements for generating sets’ power control

Table 7

Minimum time to maintain power generation in proportion to frequency band of the electricity system

Frequency band Minimum time
Hydro power plants Thermo power plants
From 46 Hz to 47.5 Hz 20 seconds Not required
From 47.5 Hz to 48.0 Hz 10 minutes 10 minutes
From 48 Hz to under 49 Hz 30 minutes 30 minutes
From 49 Hz to 51 Hz Continuous generation Continuous generation
From 51 Hz to 51.5 Hz 30 minutes 30 minutes
From 51.5 Hz to 52 Hz 03 minutes 01 minute

a) Unbalanced three-phase loads from 10% and under;

b) Indicator of response of the exciter in a synchronous generating set greater than 0.5%;

c) Negative sequence current is 5% less than rated current.

Article 39. Excitation system of a generating set

a) Minimum excitation current;

b) Maximum excitation current.

a) For a generating set of a hydro power plant: 1.8 rated value;

a) For a generating set of a thermo power plant: 2.0 rated value;

Article 40. Governor

a) For steam turbines: From 104% to 112% of rated speed;

b) For gas and thermo power turbines: From 104% to 130% of rated speed;

c) If the generating set in the grid area is temporarily disconnected from the national electricity transmission system but keeps supplying power to customers, the governor system of the generating set must maintain frequency stability for such grid area.

Article 41. Black start

Section 4. TECHNICAL REQUIREMENTS OF WIND AND SOLAR POWER PLANTS

Article 42. Technical requirements of wind and solar power plants

a) Free generation mode

b) Generating capacity control mode

Wind and solar power plants must be capable of adjusting generation of active power as commanded by the dispatch level in accordance with change of primary sources no more than 30 seconds with tolerance within ± 01 % of rated power, specifically as follows:

– Generation of power in accordance with dispatch instruction in case primary sources are equal or greater than forecast value;

– Generation of possible maximum power in case primary sources are lower than forecast value.

Table 8

Minimum time to maintain power generation in proportion to frequency band of electricity system

Frequency band Minimum time
From 47.5 Hz to 48.0 Hz 10 minutes
Over 48 Hz to under 49 Hz 30 minutes
From 49 Hz to 51 Hz Continuous generation
From 51 Hz to 51.5 Hz 30 minutes
Over 51.5 Hz to 52 Hz 01 minute

Where:

– ΔP: Level of active power reduction (MW);

– Pm: Active power in proportion to the point of time prior to power reduction (MW);

– fn: Electricity system frequency prior to power reduction (Hz).

a) If a power plant generates an active power greater or equal to 20% of rated active power and voltage in normal operation band, such power plant must be capable of adjusting reactive power continuously in a power factor from 0.85 (corresponding to reactive power generation mode) to 0.95 (corresponding to reactive power receiving mode) at connection point in proportion to rate power;

b) If a power plant generates an active power less than 20% of rated power, such power plant may reduce ability to receive or generate reactive power in accordance with characteristics of the generating set;

c) If voltage at connection point is within ± 10 % of rated voltage, the power plant must be capable of adjusting voltage at connection point with deviation no more than ± 0,5 % of rated voltage in permissible working band of the generating set;

d) If voltage at connection point varies beyond ± 10 % of rated voltage, the power plant must be capable of adjusting reactive power to the minimum of 2% compared with rated reactive power in proportion to each per cent of voltage varying at connection point.

a) Voltage less than 0.3 pu, minimum time is 0.15 seconds;

b) Voltage from 0.3 pu to under 0.9 pu, minimum time is calculated in following formula:

 

Tmin = 4 x U – 0.6

Where:

– Tmin (second): Minimum time to maintain power generation:

– U (pu): Actual voltage at connection point (pu).

c) Voltage from 0.9 pu to under 1.1 pu, wind and solar power plants must maintain continuous generation;

d) Voltage from 1.1 pu to under 1.15 pu, wind and solar power plants must maintain generation for three seconds;

dd) Voltage from 1.15 pu to under 1.15 pu, wind and solar power plants must maintain generation for 0.5 seconds;

Section 5. PROCEDURES FOR CONNECTION AGREEMENT

Article 43. Procedures

a) A written request for connection accompanied by information according to the form in Annexes 1A, 1A 1B, 1C enclosed herewith;

b) Technical documents concerning equipment expected for connection or possible changes at existing connection points;

c) Expected time for project completion, economic – technical figures of new connection or connection change projects.

a) Review requirements concerning the equipment expected for connection;

b) Preside over assessment of effects of connection of equipment, electrical grid, power plants of customers on transmission grid including following subject matters:

– Calculate reset modes of regional electrical grids under requests for connection in the next 10 years including calculation of all alternatives and assess ability of regional transmission grid to meet N-1 criterion;

– Calculate and assess short-circuit current at connection points to the transmission grid;

– Determine obligations and constraints from new connections that may have effects on safe and stable operation of electricity transmission system;

– Assess ability to meet requirements for operation of the electricity system prescribed in Chapter II herein and technical requirements of connection points prescribed in this Chapter;

c) Prepare a draft connection agreement according to the form in Annex 2 enclosed herewith and submit it to customers who need to get connected and the dispatch level;

d) After 15 working days at the latest since receipt of the application for connection from customers, the transmission network operator shall submit a written request to the dispatching with control authority and relevant units for official suggestions as follows:

– Assessment of impacts of connection on the electricity transmission system;

– Technical requirements of equipment at connection points, requirements of operation and dispatching of generating sets, requirements of frequency load shedding system of electricity customers to ensure compliance with technical and operation requirements prescribed in Chapter II and Chapter V herein;

– Draft connection agreement in accordance with provisions prescribed in annexes enclosed herewith.

Article 44. Time limit for execution of connection agreement

Time limit for negotiation and signing of the connection agreement is prescribed in Table 9 below:

Table 9

Time limit for review and signing of connection agreement

Implementation steps Implementation time Responsibility
Submit an application for connection   Customers who need to get connected
Examine the application, prepare a draft connection agreement and deliver it to other units for collection of suggestions. No more than 35 working days since receipt of the application The transmission network operator shall preside over and cooperate with the dispatch level and relevant units.
Complete the draft connection agreement, negotiate and sign the connection agreement No more than 20 working days since receipt of suggestions from relevant units The transmission network operator and customers who need to get connected

Section 6. IMPLEMENTATION OF CONNECTION AGREEMENT

Article 45. Rights to get access to equipment at connection points

The transmission network operator and customers who need to get connected shall have the rights to get access to the equipment at connection points during survey process to make plans for connection, construction, installation, testing, replacement, removal, operation and maintenance of connection equipment.

Article 46. Dossier for inspection of energizing conditions

a) Written records of inspection of individual parts and whole of connection equipment, transmission lines and transformers (according to technical standards of Vietnam or international standards applicable in Vietnam and technical requirements of connection equipment prescribed in this Chapter);

b) Approved technical documents, amendments and supplements (if any) to initial design including following documents:

– General explanation, electrical equipment layout;

– Schematic diagrams of protective relay, automation and control system that represents circuit breakers, current transformers, voltage transformers, lightning arrestor, disconnect switches …;

– Secondary diagrams of protective relay, automation and control system;

– Diagrams detailing connection to the transmission grid and parameters of transmission lines;

– Other relevant diagrams (if any).

c) Documents concerning technical parameters and operation management including:

– Technical parameters of equipment including parameters of transmission lines;

– Documents concerning primary energy system, excitation systems, governors, simulation modeling, PSS, Laplace transform diagram together with other installation values (for construction of new power plants);

– Instruction manuals for setting of protective relays, automation, specialized software;

– Instruction manuals for equipment operation and other technical documents.

d) Calculations and proposals for trial operation, energizing and putting the plant into operation.

a) At least three months prior to date of initial trial operation of the power plant;

a) At least three months prior to the date of initial trial operation of the power plant;

a) Equipment numbering diagram;

b) Requirements for methods of receiving dispatch instruction;

c) Settings of protective relays of the customer from connection points; protective relay settings note within transmission grid and other settings related to protective relays of the customer;

d) Agreed energizing method;

dd) Requirements for testing and calibration of equipment;

e) Requirements for establishment of communication system serving dispatching;

g) Requirements for connection and operation of SCADA, monitoring equipment, PMU and PSS;

h) Requirements for installation of information technology system and other necessary infrastructure serving electricity market operation;

i) Procedures related to electricity system and market operation;

k) Lists of relevant officials and dispatchers accompanied by phone and facsimile numbers.

a) Trial operation schedules, methods of energizing and putting the electrical equipment into operation agreed with the dispatch level;

b) Agreement for assignment of responsibility of relevant parties for management and operation of connection equipment;

c) Internal regulation on safe operation of connection equipment;

d) Lists of qualified operators as prescribed in the national electricity system dispatch procedure issued by the Ministry of Industry and Trade including full name, professional title, responsibility, phone number.

Article 47. Inspection of conditions for energizing connection points

Article 48. Energizing connection points

a) Written confirmations of fulfillment of legal and technical procedures:

– Equipment within the scope of energizing that meet operational and technical requirements at connection points;

– Copy of the written record of inspection;

– Measurement system completed as prescribed, electrical meter indicators finalized;

– Signed power purchase agreement (PPA) or any agreement for power purchase;

– Dossier of work acceptance according to the law on construction:

– Primary equipment numbered according to the primary diagram issued by the dispatch level;

– Protective relay, automation, control, excitation and governor systems that have been installed and set in accordance with requirements prescribed herein and by the dispatch level;

– Lists of qualified operators as prescribed in the national electricity system dispatch procedure issued by the Ministry of Industry and Trade including full name, professional title, responsibility, phone number.

– Means of communications serving dispatching as prescribed in the national electricity system dispatch procedure issued by the Ministry of Industry and Trade;

– Connection to SCADA, monitoring system, PMU and communication system of the dispatch level fully completed;

– Operation coordination procedure agreed between the generating unit and the dispatch level.

Article 49. Trial operation, acceptance and official operation of equipment behind connection points

a) Technical specs of electrical equipment, transmission lines, transformers and generating sets;

b) Test results and installation parameters of excitation and governor systems;

c) Other technical requirements as agreed in the connection agreement.

If equipment of customers who need to get connected fails to meet requirements prescribed herein and signed connection agreement, the transmission network operator or the dispatch level has the right not to connect the power plant or electrical grid of the customer to the transmission grid and request the customer to take remedial measures.

Article 50. Inspection and monitoring of equipment after put into official operation

a) Inspect the ability of the equipment to meet provisions prescribed herein, technical regulations applicable in Vietnam and particular requirements of the signed connection agreement;

b) Inspect the compliance of the equipment with terms and conditions under the PPA and the signed connection agreement;

c) Assess impacts of electrical grid, power plants of the customer using transmission grid on safe and reliable operation of the national electricity system;

d) Reset technical parameters of generating sets and electrical grids of the customer using transmission grid to serve safe, stable and reliable operation of the national electricity system.

a) If inspection result shows that the equipment fails to meet provisions prescribed herein and applicable technical regulations, the customer using transmission grid shall incur all the expenses for inspection and additional tests;

b) If inspection result shows no violation, the requester shall incur all the expenses for inspection and additional tests. For requirements for inspection as prescribed in Point c and Point d, Clause 1, this Article, the dispatch level must report to the Electricity Regulatory Authority before carrying out inspection.

a) Test result shows that one or several operational characteristics are inconsistent with parameters published by the generating unit;

b) When the dispatch level and the generating unit do not reach a common agreement on operational characteristics of the generating set;

c) Trial operation or inspection at the request of the generating unit;

d) Tests of fuel change.

Article 51. Replacement of equipment at connection points

Section 7. PREPARATION FOR ENERGIZING ELECTRICAL EQUIPMENT OF TRANSMISSION NETWORK OPERATOR

Article 52. Dossier for inspection of connection point energizing conditions

a) Main connection diagram, primary one-line diagram, layout of electrical equipment, schematic diagram of protective relay, automation and control systems representing circuit breakers, current transformers, voltage transformers, lightning arrestor;

b) Instruction manuals for setting of protective relays, automation, specialized software;

c) Documents and technical specs of installed equipment;

d) Secondary diagrams of protective relay, automation and control system;

dd) Diagrams detailing connection to electrical works of the transmission network operator and parameters of transmission lines;

e) Other relevant diagrams (if any);

g) Plans for energizing work items, schedules for trial operation, energizing and operation.

a) Trial operation schedules, methods of energizing and operating electrical equipment;

b) Equipment numbering diagram;

c) Requirements for methods of receiving dispatch instruction;

d) Relay setting notes for protective relays of the transmission network operator;

dd) Requirements for testing and calibration of equipment;

e) Requirements for establishment of communication system serving dispatching;

g) Requirements for connection and operation of SCADA system;

h) Processes related to electricity system and market operation;

i) Lists of relevant officials and dispatchers accompanied by phone and facsimile numbers.

Article 53. Energizing

a) Written confirmations of fulfillment of legal and technical procedures:

– Equipment within the scope of energizing that meets operational and technical requirements at connection points;

– Measurement system completed as prescribed, electrical meter indicators finalized;

– Dossier of work acceptance according to the law on construction.

– Primary equipment numbered according to the primary diagram issued by the dispatch level;

– Protective relay and automation system reset in accordance with the requirements of the dispatch level.

– Lists of qualified operators as prescribed in the national electricity system dispatch procedure issued by the Ministry of Industry and Trade including full name, professional title, responsibility, phone number.

– Means of communications serving dispatching as prescribed in the national electricity system dispatch procedure issued by the Ministry of Industry and Trade;

– Connection to SCADA, monitoring system, PMU and communication system of the dispatch level fully completed.

Article 54. Replacement of equipment on transmission grid

Section 8. DISCONNECTION AND RECONNECTION

Article 55. General provisions on disconnection and reconnection

a) Voluntary disconnection;

b) Compulsory disconnection.

Article 56. Voluntary disconnection

a) Permanent disconnection of the customer using transmission grid from the electricity transmission system and responsibility of relevant parties must be stated in the PPA and connection agreement.

b) Responsibility of the customer using transmission grid for permanent disconnection from the electricity transmission system:

– Make a written notice to the transmission network operator and the dispatch level at least two months prior to the date of permanent disconnection in case the customer does not possess any generating set connecting to the transmission grid.

– Make a written notice to the transmission network operator and the dispatch level at least six months prior to the date of permanent disconnection in case the customer possesses a generating set connecting to the transmission grid.

In case of temporary disconnection from the electricity transmission system, the customer using transmission grid must make a written notice to and reach an agreement with the transmission network operator and the dispatch level on the time of disconnection at least one month prior to the date of temporary disconnection.

Article 57. Compulsory disconnection

a) At the request of competent state agencies when the customer using transmission grid violates the regulation;

b) As stated in the PPA or connection agreement;

c) Cases prescribed in Clause 5, Article 50 herein.

Article 58. Reconnection

The transmission network operator shall be responsible for performing reconnection in following cases:

Chapter VI

OPERATION OF ELECTRICITY TRANSMISSION SYSTEM

Section 1. OPERATING PRINCIPLES

Article 59. Operation modes of electricity transmission system

a) Generating capacity and loads are in the state of balance;

b) No load shedding made;

c) Load carrying level of the lines and transformers in the transmission grid is below 90% of rated value;

d) Power plants and other electrical equipment operate within permissible parameter band;

dd) Electricity system frequency is within permissible band in normal operation mode as prescribed in Article 4 herein;

e) Voltage level on the transmission grid is within permissible band in normal operation mode as prescribed in Article 6 herein;

g) Reserve power of the national electricity system is readily available to maintain frequency and voltage of the national electricity system within the band in normal operation mode; the equipment automatically works within permissible scope to ensure no load shedding in case of incident.

a) Frequency regulation reserve, spinning reserve and quick-start reserve levels are lower than required in normal operation mode;

b) Load carrying level of the lines and transformers in the transmission grid is from 90% and on but not in excess of rated value;

c) Voltage level on the transmission grid is beyond permissible range in normal operation mode but within permissible voltage range in case of single fault as prescribed in Article 6 herein;

d) Natural disasters or unusual weather conditions that are likely to affect electricity supply security;

dd) Issues related to national defense and security likely to threaten electricity system security

a) Electricity system frequency is beyond permissible band in normal operation mode but within permissible band in case of a single fault as prescribed in Article 4 herein;

b) Voltage level on the transmission grid exceeds permissible range in case of a single fault as prescribed in Article 6 herein;

c) Load carrying level of any electrical equipment in the transmission grid is beyond rated value but under 110% of rated value when an incident caused by an overload to the equipment may lead to an extreme emergency mode.

a) Electricity system frequency exceeds permissible band in case of a single fault as prescribed in Article 4 herein;

b) Load carrying level of any equipment in the transmission grid or equipment connecting to the transmission grid is from 110% of rated value and on when an incident caused by an overload to the equipment may result in disintegration of individual components of the electricity system.

c) That the electricity transmission system operates in an emergency mode and measures taken to bring the system to the state of stable operation fail has resulted in the disintegration of individual components of the electricity transmission system or voltage collapse in the electricity system.

Article 60. Operating principles of electricity transmission system

 

a) Ensure safety, stability and reliability of the operation

a) Ensure compliance with requirements for anti-flooding, irrigation and maintenance of ecological currents according to the approved procedures for hydroelectric reservoir operation;

c) Ensure obligations for sources of primary fuel for thermo power plants;

d) Ensure permissible technical conditions of generating sets and transmission grids;

dd) Ensure execution of agreement for electrical production and power through PPAs or electricity import, export contracts;

e) Ensure principles of minimizing expenses for purchasing electricity for the entire electricity system.

a) Equipment and transmission grid maintenance and repair plan;

b) Assessment of electricity system security;

c) Load forecasts, plans for supply of fuel to thermo power plants, progress of operation of new electrical works, hydrographical forecasts of hydro power plants, calculations of electricity system reserves, power supplies and ancillary service mobilization plans, and load shedding (if any) to ensure electricity system security;

d) Warnings about the decline in electricity system security (if any).

a) The plan for electricity transmission system operation in the next year (year N+1) formulated by the electricity system and market operator must be in compliance with the method of national electricity system operation in the next year (year N+1) as prescribed in the national electricity system dispatch procedure issued by the Ministry of Industry and Trade;

b) Plan for operation of electricity transmission system in year N+2 must include assessment of electricity system security, orientation of operational scenarios and medium-term measures to ensure the national electricity system operates in a safe, reliable and stable manner.

a) In normal operation mode, the electricity system and market operator shall be responsible for operating and dispatching the electricity system and assuring operational standards and parameters within permissible scope in normal operation mode as prescribed in Chapter II herein and meeting the requirements prescribed in Clause 1, Article 59 herein;

b) In a warning mode, the electricity system and market operator must publish on its website the status and warnings about the electricity system and put forward necessary measures to restore the electricity system to normal operation mode;

c) In an emergency mode, the electricity system and market operator must take necessary measures to restore the electricity system to normal operation mode as soon as possible.

d) In an extreme emergency mode or in case of multi-fault or a threat to human lives or safety of equipment, load shedding can be made but must be in compliance with the procedure for handling of incident to the national electricity system issued by the Ministry of Industry and Trade.

Article 61. Inspection and monitoring of protective relay system

The dispatch level shall request relevant units to ensure the protective relay, automation and control system in the electricity system meets the requirements prescribed herein, electrical equipment norms issued by the Ministry of Industry and Trade and technical requirements of the protective relay and automation system in power plants and transformers issued by the Electricity Regulatory Authority.

Article 62. Stable operation of electricity system

Article 63. Trial operation and monitoring

a) Re-inspect operational characteristics of the calibrated generating set after every incident;

b) Inspect the generating set after it is installed, overhauled, improved or re-assembled.

a) Records of the generating set;

b) Characteristics of the generating set;

c) Value of operational characteristics expected to change during operation.

Article 64. Handling of incident

a) Change generating capacity of the generating set, stop or start the generating set to restore frequency to the frequency band at normal operation mode;

b) Carry out load shedding on each line through an automatic under-frequency load shedding relay or under dispatch instruction;

c) Automatic under-frequency load shedding. The automatic frequency load shedding system must be arranged and installed appropriately to prevent the electricity system from falling into pieces in case of incident. The electricity system and market operator shall be responsible for determining installation positions and settings of the low-frequency relay and carry out load shedding in case of incident.

d) Construct methods of separating the system into regions or creating a ring circuit to be able to balance power in each region in case of an incident, to maintain operation of individual components of the electricity system and prevent the incident from spreading throughout the electricity system.

dd) When the frequency increases to the permissible value, the electricity system and market operator shall restore the loads shedded;

e) The electricity system and market operator has the right to interfere in to restrict constant separation of generating sets, loading lines from operation;

g) In case part or whole of the electricity system falls to pieces, the electricity system and market operator shall be allowed to appoint a power plant with black start capability to restore the electricity system. If necessary, the electricity system and market operator may request the power plant to operate the generating set without relying on operational characteristics provided that the safety of human beings and equipment is assured. The generating unit shall be responsible for complying with black start instruction and making notification to the electricity system and market operator. The electricity system and market operator shall be responsible for restoring all the loads appropriately to ensure stable operation of the generating set and synchronizing other generating sets.

Article 65. Notice of decline in electricity system security

a) State of decline in electricity system security;

b) Causes;

c) Possible load shedding;

d) Affected units and areas.

a) Areas subject to suspension or reduction of power supply;

b) Reasons for suspension or reduction of power supply;

c) Time of starting suspension or reduction of power supply;

d) Expected time for restoration of power supply.

a) Areas subject to suspension or reduction of power supply;

b) Reasons for suspension or reduction of power supply;

c) Start time for suspension or reduction of power supply;

d) Expected time for restoration of power supply.

a) Make written notification of decline in electricity system security to relevant units and publish the notification on the website of the electricity system and market operator according to annual, monthly electricity system operation plans;

b) Give dispatch instruction within competence and publish the notification of decline in electricity system security on the website of the electricity system and market operator according to weekly, daily electricity system operation plans and methods.

Article 66. Load shedding for electricity system security

Section 2. RESPONSIBILITY OF UNITS IN OPERATION OF ELECTRICITY TRANSMISSION SYSTEM

Article 67. Responsibility of electricity system and market operator

Article 68. Responsibility of transmission network operator

Article 69. Responsibility of generating units

Article 70. Responsibility of electricity distribution units, electricity retailers

Article 71. Responsibility of electricity customers

Section 3. ANCILLARY SERVICES

Article 72. Types of ancillary services

Types of ancillary services used to adjust frequency and voltage during operation of the electricity transmission system:

Article 73. Technical requirements of ancillary services

Article 74. Principles of determining demand for ancillary services

a) Maintain electrical energy and capacity reserves of the electricity system in accordance with operation and electricity system security standards;

b) Ensure minimum expenses in accordance with conditions and obligations of the national electricity system.

a) Frequency regulating reserve is the amount of necessary available capacity in the national electricity system readily available for being mobilized, dispatched to control primary frequency for a specified period of time in order to maintain electricity system frequency within permissible band;

b) Spinning reserve is the amount of necessary available capacity in the national electricity system readily available for being mobilized, dispatched in order to restore electricity system frequency to permissible band after a single fault;

c) Quick-start: Quick-start reserve must be capable of compensating difference between appropriate reserve power determined in Article 93 herein and reserve power stipulated in Article 94 herein;

d) Voltage adjustment: Voltage adjustment must ensure efficient mobilization of reactive power to maintain voltage at busbars on transmission grids meeting standards in normal operation mode;

dd) Must-run operation reserves to ensure electricity system security: The electricity system and market operator shall be responsible for calculating and comparing operation modes with and without obligations on the simulation modeling of the electricity system and market with account taken of following cases:

– Ensure satisfaction of requirements for electrical energy and capacity of electrical grid connecting the countries in the region;

– Maintain standards on voltage and stability of the national or regional electricity systems.

e) Black start: Function of the black start is to ensure efficient mobilization of power and be readily available when the electricity system has a wide-area outage. The electricity system and market operator shall be responsible for calculating and analyzing incidents likely to separate the transmission grid into isolated regions for calculation and determination of requirements of black start services in the electricity transmission system.

Article 75. Registration of ancillary services

Section 4. MAINTENANCE AND REPAIR OF ELECTRICITY TRANSMISSION SYSTEM

Article 76. General provisions on maintenance and repair of electricity transmission system

a) Ensure safe, stable, reliable and economical operation of the entire national electricity system;

b) Balance source power and loads, have sufficient reserve power, electrical power and necessary ancillary services in operation modes of the national electricity system;

c) Optimize coordination in the maintenance and repair of equipment, electrical grids and power plants with hydrographical condition obligations, requirements for supply of lowland water, flood prevention and supply of primary fuel for power generation ;

d) Short-term maintenance and repair plans must be formulated based on long-term maintenance and repair plans;

dd) Ensure possible highest reserve electrical energy and capacity of the national electricity system in peak hours. Prioritize maintenance and repair during the period of low loads of the national electricity system;

e) Minimize suspension and reduction of power supply from the national electricity system; minimize maintenance and repair during the period of time when political, cultural and social events take place.

a) Annual maintenance and repair plan: The plan shall be formulated for the next year (year N+1) with account taken of the year thereafter (year N+2) serving the formulation of annual electricity system operation plan and medium-term assessment of electricity system security;

b) Monthly maintenance and repair plan: The plan shall be formulated and updated on a monthly basis with account taken of the month thereafter on the basis of the approved annual maintenance and repair plan;

c) Weekly maintenance and repair schedule: The schedule shall be formulated for the next week with account taken of the week thereafter on the basis of the approved monthly maintenance and repair plan;

d) Daily maintenance and repair schedule: Determine the maintenance and repair tasks to be performed next day.

a) Name of equipment that needs maintenance and report;

b) Requirements and subject matters of maintenance and report;

c) Expected time for starting and completing maintenance and repair tasks;

d) Other relevant equipment.

Article 77. Establishment of plan for maintenance and repair of electricity transmission system

a) Annual maintenance and repair plan: Annually published;

b) Monthly maintenance and repair plan: Published on a monthly basis;

c) Weekly maintenance and repair schedule: Published on a weekly basis;

d) Daily maintenance and repair schedule: Published on a daily basis;

Article 78. Order of priority on separation of equipment for maintenance and repair

a) Separation of equipment for maintenance and repair of power source is more prioritized than the transmission grid;

b) Separation of equipment for maintenance and repair of power sources shall be prioritized according to the principle of minimizing expenses for purchase of power for the entire system;

c) If two or more requests for separation of equipment for maintenance and repair of power sources affect generating costs, any request that comes first shall be given higher priority.

Article 79. Registration for separation of equipment for maintenance and repair

a) Registration of maintenance and repair according to the plan is the registration of separation of equipment for maintenance and repair on the basis of the plan for maintenance and repair of electricity transmission system formulated and published by the electricity system and market operator.

b) Registration of maintenance and repair outside the plan is the registration of separation of equipment for maintenance and repair outside the plan for maintenance and repair of electricity transmission system formulated and published by the electricity system and market operator.

c) Registration of unscheduled maintenance and repair is the registration for separation of equipment in operation in the state of possible hazards.

a) Name of equipment;

b) Main tasks;

c) Expected time for task performance;

d) Expected time for inspection and trial operation;

dd) Expected time for separating and bringing equipment back to work;

e) Other equipment that needs isolation;

g) Other necessary information.

Article 80. Separation of equipment in operation for urgent repair

If the equipment in operation is likely to threaten human life or safety, the operator from the transmission network operator or the customer using transmission grid has the right to separate the equipment immediately from the electricity transmission system and take full responsibility for the separation.

Article 81. Reports on urgent separation of equipment for repair

In case of urgent separation of equipment, relevant units shall be responsible for making reports as follows:

Section 5. ELECTRICITY SYSTEM SCHEDULING AND DISPATCHING

Article 82. Day-ahead mobilization schedules

Article 83. Obligations for system security

a) Transmission grid obligations;

b) Generating sets’ generating capability obligations;

c) Requirements for ancillary services;

d) Necessary obligations to ensure electricity supply security as prescribed in Article 60 and Article 62 herein.

Article 84. Real-time dispatching

a) Ensure real-time dispatching of generating sets and ancillary services is carried out in an apparent way for the parties involved in the electricity market;

b) Ensure the electricity system operates in a safe, stable and reliable manner as prescribed.

a) The electricity system and market operator shall be responsible for operating and dispatching electricity system in real time, issuing dispatch instruction and complying with relevant procedures and regulations. The schedules of real-time mobilization of generating sets must meet obligations for electricity system security and minimize expenses for the entire system;

b) The real-time dispatching of electricity system must be based on day-ahead mobilization schedules and schedules for real-time mobilization of generating sets. In case of emergency, to ensure electricity system security, the electricity system and market operator has the right to operate the electricity system not in accordance with the schedules of real-time mobilization of generating sets. Such changes must be recorded in the operation diary and reported to relevant parties;

c) The units involved in the electricity market must comply with dispatch instruction of the electricity system and market operator;

d) Dispatch instructions must be recorded in the dispatch diary, tape recorder and database of the electricity system operation management software;

dd) After the real-time operation, the electricity system and market operator must publish information concerning dispatch instruction, operation of electricity system on its website.

Article 85. Methods of real-time operation of electricity system

The system and market operator shall be responsible for ensuring supply – demand balance in real time by issuing dispatch instruction and operation actions based on day-ahead transaction cycle mobilization schedules;

a) If the measures prescribed in Point b, Clause 1, this Article have been taken but the electricity system fails to return to normal operation, the electricity system and market operator shall be responsible for mobilizing generating sets to provide quick-start reserve services based on day-ahead transaction cycle mobilization schedules and ensure minimization of expenses for the entire system;

b) The electricity system and market operator shall be responsible for publishing mobilization schedules of ancillary services on its website according to the regulation on competitive electricity market operation.

Section 6. COORDINATION IN OPERATION, EXCHANGE OF INFORMATION AND OPERATIONAL REPORTING MODES

Article 86. General responsibility for operation coordination

Article 87. Exchange of information

a) Name and position of the person who gives the notification, makes the report or answers the questions, time of notification, reporting or answering the questions;

b) Information concerning operation, incidents or risks;

c) Verbal or oral reports on the incident or answers to the questions. Reports on incidents or answers to questions must include:

– Information concerning the causes, effects or damage caused by the incident, accidents or casualties; remedial measures and results of implementation of such measures;

– If an incident can be remedied immediately, the report is made orally;

– If the incident happens in a factory, the report must be made by such factory. If an incident happens in the electricity system connecting to the national transmission grid, the customer using transmission grid shall make a report on such incident or answer the questions; if an incident happens on the national transmission grid, the transmission network operator shall make the report or answer the questions.

Article 88. Confidentiality

All the information concerning the operation process or incident handling shall be provided to a third party in following cases:

Article 89. Reporting of incidents in national electricity system

a) For a lasting incident on the electricity transmission system from 220 kV and over that causes damage to the equipment or an incident occurring to the national electricity system that causes extensive outage in a province, a central-affiliated city or an incident that results in load shedding with capacity from 200 MW and over, report the incident to the Electricity Regulatory Authority via texting or email after the element of incident in the national electricity system is isolated.

b) Within 36 hours since the incident happens, the dispatch level shall send the report to the Electricity Regulatory Authority according to the form in Annex 3 enclosed with the incident handling procedure issued by the Ministry of Industry and Trade;

c) Before 20th every month, the electricity system and market operator shall make a review report of incidents according to the form in Annex 4 enclosed with the incident handling procedure issued by the Ministry of Industry and Trade (for incidents subject to analysis and scrutiny) and incidents of last month to the Electricity Regulatory Authority by post or via email in following cases:

– Lasting incidents on 500 kV electrical grid;

– Lasting incidents on 220 kV, 110 kV electrical grids and power plants cause extensive outage in a province, central-affiliated city or a district of Hanoi Capital and Ho Chi Minh City or a load shedding with capacity from 200 MW and on or have direct impact on the operation of the power plant involved in the competitive electricity market.

Article 90. Reporting of performance of transmission grid

a) Operation of transmission grid;

b) Assessment of implementation of operation standards prescribed in Chapter II herein;

c) Overloads, incidents and causes, proposal for measures to ensure safe and reliable operation of the electrical grid;

d) Performance quality assessment indices prescribed in Article 98 herein and explanations of reasons for not meeting the indices;

dd) Connection of SCADA of transformers to the dispatch level.

a) Before January 15 annually, the transmission network operator shall be responsible for reporting operation of transmission grids from last year including matters prescribed in Clause 1, this Article to the Electricity Regulatory Authority and the electricity system and market operator.

b) Before 15th every month , the transmission network operator shall be responsible for reporting operation of transmission grids from last month including matters prescribed in Clause 1, this Article to the Electricity Regulatory Authority and the electricity system and market operator.

Article 91. Reporting of operation plan and result of operation of national electricity system

a) Structure of mobilization of power supplies, total installed and available capacity of power supplies; progress of operation of new power supplies and electrical grids;

b) Assessment of implementation of operation standards prescribed in Chapter II herein;

c) Assessment of demand for loads and consumption of power, tolerance of load forecasting;

d) Assessment of result of operation of transmission grids, incidents and causes, proposal for measures to ensure safe and reliable operation of the electrical system;

dd) Performance quality assessment indices prescribed in Article 97 herein and explanation of reasons for not meeting the indices;

e) Statistical figures about supply of fuel, hydrographical conditions of hydroelectric reservoirs, mobilization of power plants; incidents to power supplies and electrical grids;

g) Connection of SCADA of power plants and transformers within control authority.

a) Before January 31 annually, the electricity system and market operator shall be responsible for reporting operation of the national electricity system from last year including matters prescribed in Clause 2, this Article to the Electricity Regulatory Authority.

b) Before 25th every month, the electricity system and market operator shall be responsible for reporting operation of the national electricity system from last month including matters prescribed in Clause 2, this Article to the Electricity Regulatory Authority.

Chapter VII

ASSESSMENT OF ELECTRICITY SYSTEM SECURITY

Article 92. General provisions on assessment of electricity system security

a) Medium-term assessment includes:

– Annual assessment: To be carried out to assess ability to ensure national electricity system security for the next year (year N+1) and the year thereafter (year N+2). Unit of calculation is month;

– Assessment of electricity system security for the next 12 months: To be carried out from July to end of June in the next year (year N+1) to assess ability to ensure national electricity system security for the next 12 months. Unit of calculation is month;

– Monthly assessment: To be carried out to assess ability to ensure national electricity system security for the remaining months of the year. Unit of calculation is month;

– Weekly assessment: To be carried out to assess ability to ensure national electricity system security for the remaining weeks of current month and weeks of next month. Unit of calculation is week;

b) Short-term assessment: To be carried out to assess ability to ensure national electricity system security for the next two weeks. Unit of calculation is hour;

Article 93. Reserve capacity and electrical energy of electricity system

a) Determination of appropriate reserve capacity

– Reserve capacity is the difference between total forecast available generating capacity of a generating set in the electricity system and forecast maximum capacity of loads of electricity system at the same time;

– Optimal reserve capacity is reached when the marginal cost of shortage of electrical energy caused by the incident to power supplies, changes to primary fuel and sudden increase of loads is equal to the marginal cost of mobilizing quick-start reserve to make up for such shortage;

– Appropriate reserve capacity is the optimal reserve capacity with account taken of changes of loads and generating set obligations in the electricity system.

b) Determination of appropriate reserve electrical energy

– Reserve electrical energy is the difference between total forecast available electrical energy of a generating set in the electricity system and forecast electrical energy of loads of the electricity system at the same time;

– Optimal reserve electrical energy is reached when the marginal cost of shortage of electrical energy caused by the incident to power supplies, changes to primary fuel and sudden increase of loads is equal to the marginal cost of mobilizing quick-start reserve to make up for such shortage;

– Appropriate reserve electrical energy is the optimal reserve electrical energy with account taken of changes of loads and generating set obligations in the electricity system;

a) Calculation of reserve capacity serving the formulation of plan for mobilization of quick-start reserve including:

– Registered generating capacity of generating sets of a power plant that has signed a long-term PPA;

– Failure rate of each generating set shall be determined based on statistical figures or calculations made by the electricity system and market operator for such generating sets;

– Load forecasts calculated by the electricity system and market operator are prescribed in Chapter III herein;

– The cost of shortage of electrical energy shall be determined through probability and statistics in case the demand for loads is greater than total available capacity of power supplies and value of lost load calculated by the electricity system and market operator.

b) Calculation of reserve capacity serving plans for temporary suspension and reduction of power supply and load shedding including:

– Announced available generating capacity of generating sets of a power plant;

– Failure rate of each generating set shall be determined based on statistical figures or calculations made by the electricity system and market operator for such generating sets;

– Load forecasts calculated by the electricity system and market operator are prescribed in Chapter III herein;

– The cost of shortage of electrical energy shall be determined through probability and statistics in case the demand for loads is greater than total available capacity of power supplies and value of lost load calculated by the electricity system and market operator.

c) Calculation of reserve electrical energy serving the formulation of the plan for mobilization of must-run operation reserve to ensure electricity system security, including:

– Registered capacity of generating sets of a thermo power plant that executes a long-term PPA or the contract for fast-start reserve service with corresponding failure rate;

– Failure rate of each generating set shall be determined based on statistical figures or calculations made by the electricity system and market operator for such generating sets;

– Forecast changes to electrical production of thermo power plants shall be based on past figures or actual hydrographical figures;

– Load forecasts calculated by the electricity system and market operator are prescribed in Chapter III herein;

– The cost of shortage of electrical energy shall be determined through probability and statistics in case the demand for loads is greater than total available capacity and value of lost load calculated by the electricity system and market operator.

d) Calculation of reserve electrical energy serving plans for temporary suspension and reduction of power supply and load shedding including:

– Announced electrical energy of generating sets of a power plant over stages;

– Failure rate of each generating set shall be determined based on statistical figures or calculations made by the electricity system and market operator for such generating sets;

– Forecast changes to electrical production of thermo power plants shall be based on past figures or actual hydrographical figures;

– Load forecasts calculated by the electricity system and market operator are prescribed in Chapter III herein;

– The cost of shortage of electrical energy shall be determined through probability and statistics in case the demand for loads is greater than total available capacity and value of lost load calculated by the electricity system and market operator.

a) Impacts of cost of ancillary services;

b) Impacts on requirements for operation of the electricity system;

c) Impacts on quality of power supply;

d) Assessment of the correlation between cost of power supply and quality of power supply.

Article 94. Assessment of medium-term assessment of electricity system security

a) Load forecasts of national and regional electricity systems including maximum capacity and consumed electrical production;

b) Weekly load profile of national and regional electricity systems;

c) Plans for maintenance and repair of power supplies and electrical grids;

d) Approved weekly electrical energy of hydroelectric reservoirs;

dd) Incidents to generating sets and transmission grids;

e) Requirements for ancillary services of the national electricity system;

g) Electrical grid obligations.

a) Expected plan for maintenance and repair;

b) Weekly available capacity of generating sets;

c) Weekly energy obligations (if any) of generating sets. This information shall be provided according to the form published on the electricity system and market operator’s website.

a) Total available capacity and electrical energy with account taken of energy obligations of generating sets, plans for maintenance and repair of transmission grids and generating sets;

b) Requirements for ancillary services of the national electricity system;

c) Reserve capacity and electrical energy of the national electricity system

d) Expected obligations of transmission grids;

dd) Warnings about decline in electricity supply security (if any).

Article 95. Assessment of short-term assessment of electricity system security

  1. th day. The unit of calculation if hour.

a) Load forecasts of national and regional electricity systems including maximum capacity and consumed electrical production;

b) Plans for maintenance and repair of power supplies and electrical grids;

c) Failure rate of generating sets and transmission grids;

d) Requirements for ancillary services of the national electricity system;

dd) Electrical grid obligations.

a) Plans for maintenance and repair of equipment;

b) Available capacity of generating sets in each transaction cycle;

c) Announced capacity of generating sets in each transaction cycle;

d) Time for starting and stopping slow-start generating sets;

dd) Lowest stable generating capacity of generating sets.

a) Total available capacity and electrical energy with account taken of plans for maintenance and repair of transmission grids;

b) Load forecasts in national electricity system

c) Requirements for ancillary services;

d) Reserve capacity and electrical energy of electricity system;

dd) Expected obligations of transmission grids;

e) Warnings about decline in electricity supply security (if any).

Chapter VIII

ASSESSMENT OF QUALITY OF OPERATION OF ELECTRICITY TRANSMISSION SYSTEM

Article 96. General requirements

Article 97. Performance indicators of electricity system and market operator

On a monthly and annual basis, the electricity system and market operator shall be responsible for reporting and publish following performance indicators on the website of the Electricity Regulatory Authority:

Article 98. Performance indicators of transmission network operator

a) Statistical report on overloads of equipment on transmission grid (overload level and time);

b) Statistical report on outage of transmission grid including:

– Number of times of suspension and reduction of power supply with and without plans;

– Time for starting and stopping suspension and reduction of power supply.

c) Statistical report on busbars on transmission grids of voltage failing to meet the standards as prescribed in Article 6 herein, including:

– Statistical report on over-voltage, low voltage compared with the provisions laid down in Article 6 herein;

– Time of starting and ending each violation of the voltage standard;

– Highest and lowest voltage when the voltage standard is violated;

– Irregular events when the voltage standard is violated.

d) Issues concerning reliability of transmission grids as prescribed in Article 14 herein;

dd) Monthly loss of electrical energy on transmission grid by voltage level;

e) List of incidents leading to violation of transmission grid operation standards as prescribed in Chapter II herein. Make reports and explanation of causes of violation and proposals for changes to meet operation technical standards.

a) Ratio of investment and construction by voltage level compared with approved annual plan for development of transmission grids;

b) Total number of overloaded equipment on transmission grid in the year;

c) Total number of suspension and reduction of power supply with and without plans on transmission lines and transformers;

d) Total number of times and total period of time of violation of the voltage standard as prescribed in Article 6 herein;

dd) Issues concerning reliability of transmission grids as prescribed in Article 14 herein;

e) Loss of electrical energy on transmission grid by voltage level;

g) Total number of irregular incidents leading to violation of transmission grid operation standards.

Chapter IX

SETTLEMENT OF DISPUTES AND HANDLING OF VIOLATION

Article 99. Settlement of disputes

  1. may bring the case to the Electricity Regulatory Authority for handling according to laws.

Article 100. Handling of violation

a) Reporting date;

b) Name and address of organization and/or individual that makes the report;

c) Name and address of organization and/or individual that commits acts showing signs of violation;

d) Description of behaviors showing signs of violation;

dd) Reasons for detecting signs of violation (if any);

e) Other relevant information (if any).

The specimen report prescribed in the procedure for verification and punishment of administrative violations in the area of electricity within competence of head of the Electricity Regulatory Authority.

Chapter X

IMPLEMENTATION

Article 101. Implementation

a) Procedure for national electricity system load forecasting;

b) Procedure for formulation of plans for maintenance and repair of electrical grids and power plants in the national electricity system;

c) Procedure for medium and short-term assessment of electricity system security;

d) Procedure for formulation of national electricity system operation plan;

dd) Procedure for determination and operation of ancillary services;

e) Technical requirements for protective relay and automation system in power plants and transformers;

g) Regulations on technical and operational requirements of SCADA;

h) Procedure for trial operation and monitoring;

i) Procedure for load shedding in the national electricity system.

Article 102. Effect

 

  THE MINISTER Tran Tuan Anh

 

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