Foreword
This standard was drafted according to the rules given in GB/T 1.1-2009.
This standard is proposed and managed by the China Electricity Council.
This standard was drafted by: China Electric Power Research Institute, State Grid Electric Power Research Institute.
The main drafters of this standard are Liu Chun, Lu Hongshui, Chi Yongning, Shi Wenhui, He Guoqing, Chen Mozi, Li Dan, and Feng Kaihui.
1 Scope
This standard stipulates the technical requirements for the reactive power compensation of the photovoltaic power station to access 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.
Technical Regulations for GB/T 19964 Photovoltaic Power Station Access Power System
DL/T 448 electric energy metering device technical management procedures
3 Terms and Definitions
The following terms and definitions apply to this document.
3.1
Photovoltaic power station photovoltaic(PV) powerstation
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
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.
3.3
Send line transmission line
Transmission lines from photovoltaic power stations to the public connection point.
3.4
Photovoltaic power station dynamic reactive power response time
The photovoltaic power station starts abnormally increasing or decreasing voltage at the grid connection point until the trigger setting value is reached, and the actual output change amount of the reactive power at the grid-connected photovoltaic power station (difference between the target value and the initial value) reaches 90% of the target value of the variation. Time required.
3.5
Photovoltaic plant reactive/voltage control system response time response time of PVstation reactive power/voltage control system
Photovoltaic plant reactive voltage control system starts by receiving the reactive power/voltage control command issued by the power grid dispatching institution in real time (or by presetting) until the actual output power of the photovoltaic power station is changed at the grid connection point (target value and initial value). Difference in value) Time required to reach 90° 0 of the change target value.
3.6
Voltage eligibility rate
The percentage of the ratio of the actual operating voltage within the allowed voltage deviation range to the total running statistical time.
4 voltage deviation
PV grid power station voltage deviation should meet the following requirements:
a) Photovoltaic power stations connected to the grid through a 10(6) kV voltage level, the voltage deviation at the grid connection point being 7% of the nominal voltage of the corresponding system.
b) Photovoltaic power stations connected to the grid through a voltage rating of 35kV-110kV. The voltage deviation at the grid connection point is -3% to +7% of the nominal voltage of the corresponding system; the recovery voltage after the accident is 10% of the nominal voltage of the system.
c) Photovoltaic power stations connected to the grid through the 220kV voltage level, the voltage deviation at the grid connection point is 0% to +10% of the nominal voltage of the corresponding system; the recovery voltage after the accident is -5% to +10% of the nominal voltage of the system.
d) Photovoltaic power stations connected to the grid through voltage levels of 330kV and above. In normal operation, the maximum operating voltage at the grid connection point must not exceed +110% of the nominal voltage of the system; the minimum operating voltage should not affect the synchronization and voltage stability of the power system. , station normal use of electricity and the next level of voltage regulation.
5 reactive power
5.1 Basic requirements
5.1.1 Photovoltaic power station reactive power includes photovoltaic grid-connected inverter and photovoltaic power station centralized reactive power compensation device.
5.1.2 Photovoltaic power stations should make full use of the reactive power of the grid-connected inverters and their adjustment capabilities. When the reactive power of the grid-connected inverters cannot meet the system voltage and reactive power adjustment requirements, they should be deployed at the photovoltaic power stations. Focus on reactive power compensation devices, and comprehensively consider the various power output levels of PV power stations and the transient and dynamic processes under various operating conditions after accessing the system, and allocate sufficient dynamic reactive power compensation capacity.
5.2 Response time
5.2.1 The reactive power supply of photovoltaic power stations should be able to track the fluctuations in PV output and system voltage control requirements and respond quickly.
5.2.2 The reactive power regulation requirements of PV power stations are different. The reactive power compensation devices are different. The response time should be determined according to the regulation requirements of the grid voltage after the photovoltaic power station is connected to the people. Photovoltaic power station dynamic reactive response time should not exceed 30ms.
6 reactive capacity
6.1 Basic requirements
6.1.1 The reactive power capacity of photovoltaic power stations shall meet the principle of basic equilibrium in the sub- (voltage) layer and sub- (electrical) area. The reactive power compensation capacity shall be configured in consideration of optimizing the voltage regulation mode and reducing the line loss. And meet the standby requirements for maintenance.
6.1.2 Photovoltaic grid-connected inverters The power factor should be continuously adjustable within a range of 0.95 to 0.95.
6.2 Reactive Capacity Configuration
6.2.1 The reactive power configuration of photovoltaic power stations shall meet the relevant provisions of GB/T 19964.
6.2.2 The scope of the PV power station configuration capacity should be combined with the actual access status of the PV power station. If necessary, a special study on the reactive power and voltage of the photovoltaic power station to access the power system shall be adopted. The calculation of reactive power equipment and system special operating conditions should be fully considered.
7 reactive power compensation device
7.1 Reactive Power Compensation Device Configuration
7.1.1 Photovoltaic power station The centralized reactive power compensation device can be configured on the low side of the step-up transformer. No centralized step-up transformer photovoltaic power station can install centralized reactive power compensation devices at the collection point.
7.1.2 Photovoltaic plant reactive power compensation device configuration should be based on the actual situation of photovoltaic power stations, such as installation capacity, installation type, distribution line within the station, the length of the sending line, access to the grid situation, etc., after the determination of reactive voltage.
7.2 Operational voltage adaptability
7.2.1 In the normal operation of the power grid, the reactive power compensation device of the photovoltaic power station should adapt to various changes in the operating mode of the power grid and the operational control requirements.
7.2.2 Photovoltaic power stations are in the non-power generation period. The reactive power compensation devices installed in photovoltaic power stations shall also be operated in accordance with the instructions of the power system dispatching agency.
7.2.3 When photovoltaic power stations are installed with shunt reactors/capacitor banks or voltage-compensated reactive power compensation devices, in the event of a power grid failure or abnormality, the voltage at the grid connection point of the photovoltaic power station is higher than 1.2 times the nominal voltage, and the power is ineffective. The capacitive part of the compensation device shall exit operation within 0.2 s, and the inductive part shall be able to operate for at least 5 min.
7.2.4 When a photovoltaic power station is equipped with a dynamic reactive power compensation device, the reactive power compensation device can be taken out of operation when the voltage at the grid connection point of the photovoltaic power station is higher than 1.2 times the nominal voltage in the event of a grid fault or abnormality.
7.2.5 For photovoltaic power stations in a group of photovoltaic power stations connected to a grid with 500 kV (or 750 kV) voltage levels boosted by a 220 kV (or 330 kV) photovoltaic generation system, the voltage at the grid connection point of photovoltaic power stations is low due to power system failures. When the nominal voltage is 0.9 times, the reactive power compensation device of the photovoltaic power station shall cooperate with other reactive power sources in the station to issue reactive power in accordance with the requirements for low-voltage ride-through reactive support in GB/T 19964.
8 voltage regulation
8.1 Grid-connected inverter control requirements
8.1.1 Photovoltaic power station grid-connected inverters shall have multiple control modes, including constant voltage control, constant power factor control and constant reactive power control, etc., and have the ability to manually/automatically switch modes according to operation.
8.1.2 Photovoltaic power station grid-connected inverters shall perform reactive/voltage control according to the coordination requirements of the photovoltaic power station reactive voltage control system within its reactive power regulation range.
8.2 Reactive power compensation device control requirements
Photovoltaic power station reactive power compensation devices shall have automatic control functions, and reactive/voltage control shall be carried out within the scope of reactive power adjustment according to the coordination requirements of photovoltaic power station reactive voltage control systems.
8.3 Main Transformer and Tap Control Requirements
The main transformer of photovoltaic power station should adopt on-load voltage regulating transformer, and adjust the voltage in the substation main transformer tap control station according to the coordination requirements of the reactive voltage control system.
8.4 pressure adjustment
8.4.1 Photovoltaic power stations participating in grid voltage regulation include adjusting reactive power of grid-connected inverters of photovoltaic power stations, reactive power of reactive power compensation devices, and ratio of step-up transformers of photovoltaic power stations.
8.4.2 Under the special operation mode of the grid, when the voltage regulation requirements cannot be satisfied by adjusting the reactive power and on-load voltage regulating transformers, the voltage control shall be performed by adjusting the active power according to the instruction of the power grid dispatching institution.
9 reactive voltage control system
9.1 Basic requirements
Photovoltaic power plants should be equipped with reactive voltage control systems. The system should have multiple control modes, including constant voltage control, constant power factor control and constant reactive power control, etc. It can automatically adjust the photovoltaic power station according to the instructions of the power system dispatching agency. Reactive power, controlling the voltage of the photovoltaic power station's grid connection point is within the normal operating range, and its regulation speed and control accuracy should be able to meet the voltage regulation requirements of the power system.
9.2 Features and Performance
9.2.1 The reactive voltage control system shall have the functions of calculation, automatic adjustment, monitoring, blocking, communication, start/stop sequence control, and file recording.
9.2.2 The reactive voltage control system shall communicate with the station control and superior control (or the dispatching authority of the power system) through the communication interface to transmit information and run commands.
9.2.3 The reactive voltage control system shall be able to monitor the operating status of each component, coordinate and control the grid connected inverter, reactive power compensation device and step-up transformer tap.
9.2.4 The reactive voltage control system response time should not exceed 10s, the absolute value of the reactive power control deviation does not exceed 5% of the given value, and the voltage regulation accuracy is within 0.005 times the nominal voltage.
10 Monitoring and Assessment
10.1 Reactive and Voltage Assessment Points
Photovoltaic power station's reactive power and voltage assessment points are the PV power station's network point.
10.2 Reactive and Voltage Meters and Meters
Reactive and voltage monitoring should use instruments or meters with continuous monitoring and statistics functions. The configuration and technical requirements should be in accordance with DL/T 448.
10.3 Calculation of Voltage Qualification Rate
The formula is:
