Foreword
This standard was drafted according to the rules given in GB/T 1.1-2009.
This standard replaces GB/Z 19964-2005 ((Technical Regulations for Photovoltaic power station Access to Power Systems).
This standard is proposed and managed by the China Electricity Council.
This standard was drafted by: China Electric Power Research Institute, Chinese Academy of Sciences Institute of Electrical Engineering, State Grid Electric Power Research Institute.
The main drafters of this standard are Wang Weisheng, Xu Honghua, Liu Chun, Shi Wenhui, He Guoqing, Lu Hongshui, Zhu Weigang, Chi Yongning, Chen Mozi, Li Dan, Zhu Lingzhi, Zhang Junjun, Feng Wei, Liu Limin, and Wang Bo.
The previous versions of the standards replaced by this standard are:
―GB/Z 19964-2005.
1 Scope
This standard specifies the technical requirements for photovoltaic power station access to the power system.
This standard is applicable to newly-built, rebuilt and expanded photovoltaic power stations that are connected to the public power grid through a voltage level of 35 kV and above, and connected to the public power grid through a voltage level of 10 kV.
2 normative references
The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this document. For undated references, the latest version (including all amendments) applies to this document.
GB/T 12325 Power Quality Supply Voltage Deviation
GB/T 12326 power quality voltage fluctuations and flicker
GB/T 14549 Power Quality Public Power Harmonics
GB/T 15543 power quality three-phase voltage imbalance
General requirements for GB/T 19862 power quality monitoring equipment
GB/T 24337 Power Quality Harmonics Between Utility Grids
DL/T 448 electric energy metering device technical management procedures
DL/T 1040 Grid Operation Guidelines
3 Terms and Definitions
The following terms and definitions apply to this document.
3.1
Photovoltaic power plant photovoltaic(PV) .power station
Utilizing the photovoltaic effect of photovoltaic cells, power generation systems that convert solar radiation energy directly into electrical energy generally include transformers, inverters, and photovoltaic arrays, as well as associated auxiliary facilities.
3.2
Inverter
A device that converts DC power into AC power.
3.3
On-line point of the internet
For a photovoltaic power station with a booster station, it refers to a bus or node on the high pressure side of the booster station; for a photovoltaic power station without a booster station, it refers to the output summary point of the photovoltaic power station.
3.4
Photovoltaic power station sending line transmission line of PV power station
The transmission lines from the grid-connected photovoltaic power station to the public power grid will be referred to below as the transmission lines.
3.5
Photovoltaic power station active power of PV power station
Photovoltaic power stations lose active power to the grid and are referred to as active power.
3.6
PV power station reactive power of PV power station
Photovoltaic power stations lose reactive power to the grid and are referred to as reactive power.
3.7
Photovoltaic power station active power change of PV power station
Within a certain time interval, the difference between the maximum value and the minimum value of the active power of photovoltaic power stations, which will be referred to as the change of active power in the following.
3.8
Low voltage ride through
When a power system accident or disturbance causes the voltage of the photovoltaic power station's grid connection point to fall, the photovoltaic power station can ensure continuous operation without disconnection within a certain voltage drop range and time interval.
3.9
Islanding
Part of the power grid, which includes the load and power supply, continues to operate in isolation after being detached from the main network. Isolated islands can be divided into unplanned islands and planned islands.
Note: An unplanned island refers to an unplanned and uncontrolled occurrence of an island. Planned islands refer to islands that are planned to take place according to pre-configured control strategies.
3.10
Anti-islanding
Prevent the occurrence of unplanned island phenomenon.
4 active power
4.1 Basic requirements
4.1.1 Photovoltaic power stations shall have the ability to participate in the frequency modulation and peak shaving of the power system and comply with DL/T 104. Relevant regulations.
4.1.2 Photovoltaic power stations shall be equipped with an active power control system that has the ability to continuously and smoothly adjust the active power and be able to participate in the system active power control.
4.1.3 The photovoltaic power station active power control system shall be able to receive and automatically execute the control instructions for the changes of the active power and active power delivered by the power grid dispatching agency.
4.2 Active power change under normal operation
4.2.1 In the process of grid-connected photovoltaic power stations, normal shutdown and solar irradiance growth, the rate of change of the active power of photovoltaic power stations shall meet the requirements for the safe and stable operation of the power system. The limit shall be based on the frequency of the power system The regulation characteristics are determined by the grid dispatching agency.
4.2.2 The rate of change of the active power of the photovoltaic power station shall not exceed 10% of the installed capacity/min. It is allowed that the rate of change of the active power of the PV power plant due to the decrease of the solar irradiance exceeds the limit.
4.3 Emergency Control
4.3.1 In the event of an electric power system accident or emergency, the photovoltaic power station shall be operated according to the following requirements:
a) In the event of a power system accident or special operation, the active power of the photovoltaic power station shall be reduced in accordance with the requirements of the power grid dispatching agency.
b) When the frequency of the power system is higher than 50.2H2, reduce the active power of the photovoltaic power station according to the instructions of the power grid dispatching agency, and remove the entire photovoltaic power station in severe cases.
c) If the operation of the PV power station endangers the safety and stability of the power system, the power grid dispatching agency temporarily removes the PV power station in accordance with relevant regulations.
4.3.2 After the accident is completed and the power system returns to normal operation, the photovoltaic power station shall be operated in parallel with the dispatching instructions.
5 power forecast
5.1 Basic requirements
Photovoltaic power generation forecasting systems should be configured for photovoltaic power stations with an installed capacity of 10MW or more. The system has a 0h-72h short-term PV power forecast and a 15min-4h ultra-short-term PV power forecast function.
5.2 Forecast curve reporting
5.2.1 The photovoltaic power station automatically reports the predicted power generation curve of the photovoltaic power station in the future 15min-4h to the power dispatching organization every 15 minutes. The time resolution of the predicted value is 15 minutes.
5.2.2 The photovoltaic power station reports to the next day according to the time specified by the grid dispatching agency. From 24 to 24 hours, the predicted power generation curve of photovoltaic power generation stations has a time resolution of 15 min.
5.3 Prediction Accuracy
The average monthly absolute error of the short-term forecast of PV power generation period (excluding the controlled period) shall be less than 0.15, and the monthly pass rate shall be greater than 80%; the monthly average absolute error of the 4 hours of ultra-short-term forecast shall be less than 0.10, and the monthly pass rate shall be Greater than 85%
6 reactive capacity
6.1 reactive power
6.1.1 Photovoltaic power station's reactive power sources include photovoltaic grid-connected inverters and photovoltaic power station reactive power compensation devices.
6.1.2 The grid-connected inverter installed in the photovoltaic power station should be dynamically adjustable under the condition of rated active power output within the range of 0.95-lag 0.95, and it should be dynamically adjusted within the rectangular frame shown in Figure 1.
6.1.3 Photovoltaic power stations should make full use of the reactive power capacity of the grid-connected inverter and its adjustment capability; when the reactive power capacity of the inverter cannot meet the system voltage regulation requirements, appropriate capacity should be added to the PV power station. Reactive power compensation device, if necessary, install dynamic reactive power compensation device.
6.2 Reactive Capacity Configuration
6.2.1 The reactive power capacity of a photovoltaic power station shall be configured in accordance with the principle of basic balance between the sub- (voltage) layer and the sub- (electrical) area, and shall meet the requirements for overhaul and maintenance.
6.2.2 The power factor of the photovoltaic power station connected to the grid with a voltage rating of 10kV-35kV shall be continuously adjustable within a range of 0.98-lag and 0.98. If there are special requirements, appropriate adjustments can be made to stabilize the voltage level.
6.2.3 For photovoltaic power stations that are connected to grids with voltage ratings of 110 (66) kV and above, the reactive power configuration should meet the following requirements:
a) Capacitive reactive power capacity can compensate for the sum of the inductive convergence of the PV power station when the station is full, the sensible reactive power of the main transformer, and the sentiment of the PV power station;
b) The inductive reactive capacity can compensate for the capacitive charging reactive power of the photovoltaic power station itself and the sum of half of the charging reactive power of the transmission line of the photovoltaic power station.
6.2.4 For a photovoltaic power station in a photovoltaic power station group that is connected to a power grid and boosted to a 500 kV (or 750 kV) voltage level by a 220 kV (or 330 kV) photovoltaic power gathering system, the reactive power configuration should meet the following requirements:
a) Capacitive reactive power capacity can compensate for the sum of all perceptual reactive powers of the aggregated line, main transformer's inductive reactive power, and photovoltaic power station sending lines when the photovoltaic power generation station is full;
b) The inductive reactive capacity can compensate for the capacitive charging reactive power of the photovoltaic power station itself and the sum of all charging reactive power of the transmission lines of the photovoltaic power station.
6.2.5 The types of reactive power devices and their capacity ranges configured for photovoltaic power stations shall be determined by a special study on the reactive power voltage of the photovoltaic power stations connected to the power system in light of the actual access conditions of the photovoltaic power stations.
7 voltage control
7.1 Basic requirements
7.1.1 Photovoltaic power stations that access the grid through 10kV-35kV voltage levels shall have the ability to adjust the reactive output according to the voltage level of the photovoltaic power station's grid point and participate in the voltage regulation of the grid, and its adjustment methods Parameters such as reference voltage and voltage adjustment rate should be set by the grid dispatching agency.
7.1.2 Photovoltaic power stations connected to the grid through 110 (66) kV and above voltage levels shall be equipped with reactive voltage control systems, with reactive power regulation and voltage control capabilities. According to the instructions of the power grid dispatching agency, the photovoltaic power station automatically adjusts the reactive power it emits (or absorbs) to achieve the control of the voltage at the grid point, and its regulation speed and control accuracy should meet the voltage regulation requirements of the power system.
7.2 Control objectives
7.2.1 When the voltage of the public power grid is within the normal range, the photovoltaic power station connected to the power grid through 110 (66) kV voltage level shall be able to control the voltage of the photovoltaic power station's grid point within the range of 97% to 107% of the nominal voltage.
7.2.2 When the voltage of the public power grid is within the normal range, the photovoltaic power station that is connected to the power grid through a voltage level of 220 kV and above shall be capable of controlling the voltage of the photovoltaic power station's grid point within 100% to 110% of the nominal voltage.
7.3 Main Transformer Selection
Photovoltaic power stations connected to the grid through voltage levels of 35kV and above shall use on-load tap-changers for the main transformer of the booster station.
8 Low voltage ride through
8.1 Basic requirements
Figure 2 shows the low-voltage ride-through requirements that PV power stations should meet:
a) When the PV voltage of the PV power station drops to 0, the PV power station shall be capable of continuous operation for 0.15 s without disconnection;
b) Photovoltaic power stations can be cut out from the grid when the voltage at the grid connection point of the photovoltaic power station falls below curve 1.
8.2 Failure Types and Assessment Voltages
When there are different types of faults in the power system, if the assessment voltages of the photovoltaic power stations are all within the voltage contour line and above in Fig. 2, the photovoltaic power station shall ensure that it will not be disconnected from the grid for continuous operation; otherwise, the PV power station will be allowed to cut out. The assessment voltage for different fault types is shown in Table 1.
8.3 active power recovery
For photovoltaic power stations that have not been disconnected during power system failure, the active power of the photovoltaic power station should be quickly restored after the fault is cleared. At the moment of fault clearing, the power is restored to the normal power generation state with a power change rate of at least 30% of rated power/second.
8.4 Dynamic Reactive Support
For photovoltaic power stations in a photovoltaic power station group that is connected to the grid through a 220 kV (or 330 kV) photovoltaic power generation system and boosted to a 500 kV (or 750 kV) voltage level, when a voltage drop occurs due to a short-circuit fault in the power system, the photovoltaic power station The dynamic reactive current of the human grid should meet the following requirements:
a) The response time of the dynamic reactive current is less than 30 ms from the moment of voltage drop at the grid connection point.
b) During the period from the dynamic reactive current response until the voltage recovers to 0.9pu, the dynamic reactive current stone of the photovoltaic power station injecting power system shall track the voltage change of the grid point in real time, and shall satisfy:
IT≥1.5×(0.9-UT) IN (0.2≤UT≤0.9)
IT≥1.05×IN (UT<0.2)
1T=0 (UT>O.9)
In the formula:
UT - Photovoltaic power station grid point voltage standard value;
IN - Photovoltaic power station rated installed capacity / (/ X grid point rated voltage).
9 operational adaptability
9.1 Voltage Range
Photovoltaic power stations should be able to operate as specified in the voltage range of the grid point shown in Table 2.
9.2 Power Quality and Range
When the harmonic value of photovoltaic power station connection point meets GB/T 14549, the three-phase voltage unbalance degree satisfies GB/T 15543, and the inter-harmonic value satisfies the requirements of GB/T 24337, the photovoltaic power station shall be capable of normal operation.
9.3 Frequency range
Photovoltaic power plants should operate within the frequency range of the power system shown in Table 3.
10 power quality
10.1 Voltage deviation
After the photovoltaic power station is connected, the voltage deviation of the public connection point of the connected person shall meet the requirements of GB/T 12325.
10.2 Voltage fluctuations and flicker
After the PV power station is connected, the voltage fluctuation and flicker value of the public connection point of the connected person shall meet the requirements of GB/T 12326.
10.3 Harmonics
10.3.1 Harmonic injecting current at the public connection point of the PV power station is to meet the requirements of GB/T 14549. Including the permissible harmonic current of the PV power station connecting point to the power system should be installed according to the PV power station. The ratio of capacity to the total capacity of the sending/supplying equipment with harmonic sources at the common connection point is allocated.
10.3.2 After the photovoltaic power station is connected, the interharmonics of the public connection points of the connected people shall meet the requirements of GB/T 24337.
10.4 Voltage Unbalance
After the photovoltaic power station is connected, the unbalanced voltage of the public connection point of the connected person shall meet the requirements of GB/T 15543.
10.5 Monitoring and Governance
Photovoltaic power stations should be equipped with real-time power quality monitoring equipment. The installed power quality monitoring equipment should meet the requirements of GB/T 19862. When photovoltaic power station power quality indicators do not meet the requirements, photovoltaic power stations should be equipped with power quality control equipment.
11 Simulation Models and Parameters
11.1 Simulation Model
Photovoltaic power stations should establish photovoltaic power generation units (including photovoltaic modules, inverters, unit boosting transformers, etc.), photovoltaic power station convergence lines, and photovoltaic power station control system models and parameters for the planning of photovoltaic power station access to the power system. Design and scheduling operation.
11.2 Parameter Changes
Photovoltaic power stations should track changes in their respective component models and parameters, and feed back the latest information to the grid dispatch agency at any time.
12 secondary systems
12.1 Basic Requirements
12. Fly.1 Secondary equipment and systems for photovoltaic power stations shall comply with the technical specifications of secondary power systems, safety protection requirements for secondary power systems, and relevant design regulations.
12.1.2 Communication methods, transmission channels and information transmission between photovoltaic power stations and power grid dispatching agencies shall be stipulated by the power grid dispatching agency, including the provision of telemetry signals, remote signaling signals, remote control signals, remote control signals, and signals of other safety automatic devices. , provide signal methods and real-time requirements.
12.1.3 The safety protection of the secondary system of photovoltaic power stations should meet the relevant regulations of the national electricity regulatory authority.
12.2 Normal operation signal
The signal provided by the photovoltaic power station to the power grid dispatching organization should include at least the following aspects:
a) The operational status of each photovoltaic power generation unit, including the operating status of the inverter and the unit step-up transformer;
b) Photovoltaic power station connection point voltage, current, frequency;
c) active power, reactive power, and power generation of the main transformer of the main step-up transformer of a photovoltaic power station;
d) The location of high voltage circuit breakers and disconnectors in photovoltaic power stations;
e) The main step-up transformer tap position of photovoltaic power station;
f) Real-time irradiance, ambient temperature and PV module temperature collected by photovoltaic power station meteorological monitoring system.
12.3 Relay Protection and Safety Automatic Devices
12.3.1 Photovoltaic power station relay protection, safety automatic devices and secondary loops shall meet the requirements of relevant standards, regulations and anti-accident measures of the power system.
12.3.2 For the transmission lines of photovoltaic power stations, sectional phase-to-phase and ground fault protection shall be configured on the system side; when there are special requirements, longitudinal differential current protection may be configured.
12.3.3 The photovoltaic power station should be equipped with an independent anti-islanding protection device, and the operation time should not exceed 2s. Anti-island protection should also be coordinated with the grid-side line protection.
12.3.4 Photovoltaic power plants shall have protective measures to quickly remove the single-phase faults of the collection system within the station.
12.3.5 Photovoltaic power plants connected to the grid through a voltage rating of 110 (66) kV or higher shall be equipped with fault recording equipment. The equipment shall have sufficient recording channels and be able to record the situation from 10 seconds before the fault to 60 seconds after the fault. Equipped with a data transmission channel to the grid dispatch agency.
12.4 PV Station Dispatching Automation
12.4.1 Photovoltaic power stations shall be equipped with computer monitoring system, remote terminal equipment for electric energy, secondary system safety protection equipment, dispatching data network access equipment, etc., and shall meet the technical requirements for technical secondary management of power secondary systems.
12.4.2 Photovoltaic Power Station Dispatch Automation System The telecontrol information acquisition scope is based on the requirements of the EMS remote control information access requirements.
12.4.3 Photovoltaic power station power metering points (gateways) shall be located at the division of property rights between photovoltaic power stations and the power grid. The division of property rights shall be determined in accordance with the relevant regulations of the State. Where an electric energy metering device is not suitable to be installed at the demarcation point of property rights, the metering point for the customs clearance shall be negotiated between the owner of the photovoltaic power station and the grid company. Metering device configuration should meet the requirements of DL/T 448.
12.4.4 Photovoltaic power plant dispatching automation and transmission of electric energy information shall adopt the communication mode of the master/standby channel and be sent directly to the power grid dispatching agency.
12.4.5 Photovoltaic Power Plant Dispatching Jurisdiction The equipment power supply shall be powered by an uninterrupted power supply (UPS) or DC power system in the station. After the AC power supply disappears, the uninterrupted power supply unit shall have a load running time greater than 40 minutes.
12.4.6 The phase angle measuring system (PMU) shall be provided for photovoltaic power stations that receive voltage levels of 220 kV and above.
12.5 Photovoltaic Power Station Communication
12.5.1 For photovoltaic power stations connected to the grid through 110kV (66kV) and above voltage levels, two communication channels shall be provided to the dispatcher, one of which is the cable channel.
12.5.2 Communication devices directly connected to the photovoltaic power station and the power system [such as optical fiber transmission equipment, pulse code modulation terminal equipment (PCM), dispatching program control exchanges, data communication network, communication monitoring, etc.] should have the same system access equipment The interface and protocol.
13 grid detection
13.1 Basic Requirements
13.1.1 Photovoltaic power stations shall provide power grid dispatching agencies with photovoltaic power station inspection access power system test reports; when the cumulative new installed capacity exceeds 10 MW, a test report shall be submitted again.
13.1.2 Photovoltaic Power Generation Stations Before applying for access to the power system for detection, the grid dispatching agency shall provide the model, parameters, characteristics and control system characteristics of the photovoltaic components and photovoltaic power stations.
13.1.3 Photovoltaic power station access The power system test shall be carried out by an organization with appropriate qualifications. The test plan shall be submitted to the power grid dispatching agency in the area where the test was conducted 30 days before the test.
13.1.4 Photovoltaic power stations shall provide inspection reports on the operational characteristics of photovoltaic power stations to the power dispatching agencies within six months of the commissioning of all photovoltaic components.
13.2 Test Content
The inspection should be conducted in accordance with the relevant standards or regulations formulated by the State or related industries for the grid-connected operation of photovoltaic power stations, including but not limited to
In the following:
a) photovoltaic power station power quality testing;
b) Photovoltaic power station active/reactive power control capability detection;
c) Verification of low voltage ride through capability of photovoltaic power stations;
d) PV power station voltage and frequency adaptability verification.
