GB/T 24847-2021Technical guide on 1000kV AC system voltage and reactive power (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This standard replaces GB /Z 24847-2009 "Technical Guidelines for 1000kV AC System Voltage and Reactive Power". With GB /Z 24847- Compared with.2009, the main technical changes are as follows.

---Modified the definitions of the terms "voltage deviation", "reactive power supply" and "reactive power compensation equipment" (see 3.2, 3.3 and 3.4, 2009 edition 3.2, 3.3 and 3.4);

---The terms "maximum operating voltage", "UHV" and their definitions have been added (see 3.5 and 3.6);

---Added the technical requirements for reactive power balance and compensation of the phase advance capability of generators running with auxiliary power (see 6.3);

---Added the technical requirements for reactive power balance and compensation capacitive reactive power compensation (see 6.10).

1 Scope

This standard specifies the basic requirements of 1000kV AC system voltage and reactive power technology, allowable deviation of voltage, and voltage and Technical principles for power allocation and adjustment.

This standard applies to 1000kV AC transmission and transformation systems and power sources connected to 1000kV AC transmission and transformation systems (hereinafter referred to as "1000kV AC system").

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this document. For undated reference documents, the latest version (including all amendments) is applicable to this document.

GB 38755-2019 Safety and Stability Guidelines for Power Systems

DL/T 1773-2017 Technical Guidelines for Power System Voltage and Reactive Power SD131-1984 Power System Technical Guidelines

IEC 60038:2009 IEC standard voltages (IEC standardvoltages)

IEEEstd1860.2014 IEEE Guidelines for AC UHV Voltage Regulation and Reactive Power Compensation Technology for 1000kV and above (IEEE guideforvoltageregulationandreactivepowercompensationat1000kVandabove)

3 Terms and definitions

Defined by GB 38755-2019, SD131-1984, DL/T 1773-2017, IEC 60038:2009 and IEEEstd1860.2014 And the following terms and definitions apply to this document.

4 Basic requirements

4.1 The planning and design of 1000kV AC system shall include reactive power planning and design.

4.2 The reactive power supply of the 1000kV AC system should be configured according to the principle of basic balance in layered and partitioned areas, and ensure that it is available in various operating modes.

It has flexible reactive power adjustment capability and sufficient spare capacity.

4.3 The 1000kV AC system shall meet the requirements of allowable voltage deviation under normal and steady-state operation after failure.

4.4 The configuration of reactive power compensation equipment and the selection of equipment types should have the function of improving the transmission capacity and stability of the power system, and ensure that the system The voltage tolerated during the dynamic process of the system does not exceed the allowable level of the equipment.

4.5 The voltage regulation range and the voltage regulation mode of the transformer tap changer of the UHV AC system should be reasonably selected according to the grid structure and operation mode.

4.6 The reactive power planning and design of the 1000kV AC system shall meet the requirements for limiting the overvoltage of the 1000kV AC system.

4.7 Strengthen the reactive power compensation configuration and voltage support of high-proportion new energy access to the sending-end system and large DC sending-end system; strengthen the multi-DC feed-in receiver End system construction and voltage support, and reserve dynamic reactive power reserve.

5 Voltage tolerance

5.1 The maximum operating voltage of the 1000kV bus should not exceed 1.1 times the nominal voltage of the system, and the minimum operating voltage should not affect the power system performance.

The angle is stable, the voltage is stable, the normal use of factory power and the adjustment of the next level of voltage.

5.2 The 1000kV bus of the power plant directly connected to the 1000kV AC system and the 500kV bus of the 1000kV substation.

---The allowable deviation of the steady-state operating voltage in the normal operating mode is 0~10% of the nominal voltage of the system;

---The allowable deviation of the steady-state operating voltage of the operating mode after the accident is -5%~15% of the nominal voltage of the system.

5.3 For a 1000kV line in a single-side empty charging state in the system, the end voltage of the line should not exceed the system after the attenuation of the transient process.

The total nominal voltage is 1.15 times, and the duration does not exceed 30min.

6 Reactive power balance and compensation

6.1 The reactive power compensation capacity of 1000kV AC system should be configured according to the principle of basic balance of reactive power hierarchical and partitioned. The specific compensation plan is determined by calculation. Calculated.

6.2 In general, the total capacity of the high and low voltage shunt reactors should be basically compensated for the charging power of the line.

The capacity configuration and withstand voltage level should be determined according to the system conditions and respective characteristics.

6.3 All generators connected to the 1000kV AC system shall have the ability to operate in phase with a power factor of 0.95 when the active power is at the rated value.

When the generator is running with auxiliary power, the phase advance capability should not be less than 0.97. The power factor of the generator at the receiving end of the 1000kV AC system, You can choose from 0.85 to 0.90.

6.4 The shunt capacitor bank and low-voltage shunt reactor of 1000kV substation shall have the function of automatic switching according to the operation mode.

6.5 The dynamic reserve capacity in the reactive power source should be mainly reserved in the running generator and the dynamic reactive power compensation device, so that it can be generated on the power grid.

When the voltage is too low due to insufficient reactive power, the reactive power capacity can be quickly increased, and when the voltage is too high due to excess reactive power in the grid, it can quickly increase the voltage.

Reduce the reactive power capacity quickly and maintain the stable operation of the power system.

6.6 For high-voltage shunt reactors, comprehensive consideration should be given to limiting power frequency overvoltage, reducing submersible current, restoring voltage, and balancing the charging power of transmission lines. Rates and other requirements require reasonable configuration.

6.7 The configuration of high and low voltage shunt reactor capacity should consider the power frequency overvoltage on the substation side of the line circuit breaker of the 1000kV AC system It does not exceed 1.3 times the maximum operating voltage of the system, and the line side short-term (0.5s) does not exceed 1.4 times the maximum operating voltage of the system.

6.8 For lines equipped with high-voltage shunt reactors, a small reactor can be connected through a neutral point to limit the submersible supply current and its recovery voltage to meet the requirements of the single Phase reclosing requirements.

6.9 When the line is equipped with high-voltage shunt reactors, the non-full-phase operation resonant overvoltage should be calculated and checked.

6.10 The capacitive reactive power compensation of 1000kV substation mainly compensates for the reactive power loss of the main transformer, and appropriately compensates for some lines and takes into account the load.

For the reactive power loss on the side, the single-group capacitive reactive power compensation capacity should be selected so that the voltage fluctuation caused by the single-group switching does not trigger the tapping of the on-load tap-changing transformer Head movement is the principle.

7 Selection of transformer voltage regulation method and voltage regulation range 7.1 The rated voltage on each side of the 1000kV transformer, the voltage regulation method, the voltage regulation range and the voltage regulation value of each gear shall meet the requirements of the power plant and substation bus And the requirements of the terminal voltage level control, and consider the needs of the medium and long-term development of the power system.

7 Selection of transformer voltage regulation method and voltage regulation range

7.2 The rated voltage of the high-voltage side of the 1000kV step-up transformer should be 1.05 times to 1.10 times the nominal voltage of the system, or after calculation and demonstration determine.

7.3 The rated voltage of the high voltage side of the 1000kV step-down transformer should be 1 to 1.05 times the nominal voltage of the system; the rated voltage of the medium voltage side should be selected Choose 1.05 times to 1.10 times the nominal voltage of the system; the nominal voltage of the low-voltage side should be chosen as the nominal voltage of the system.

7.4 The generator step-up transformer connected to the 1000kV AC system generally can be selected as a non-excitation voltage regulation type. If necessary, you can also consider selecting it. Use on-load voltage regulation.

7.5 The 1000kV step-down transformer adopts non-excitation voltage regulation type or on-load voltage regulation type, which is determined by calculation and analysis according to the operating conditions of the system. Transformation The voltage regulation range of the tap changer of the generator should be determined by calculation. The voltage regulation range of the tap changer of the non-excitation voltage regulation transformer is generally ±4×1.25%.

8 Adjustment of operating voltage

8.1 The operating position of the 1000kV transformer tap switch should be ensured that the voltage level of the power plant and substation bus and system does not exceed The allowable deviation value is determined through optimization calculations under the principle of giving full play to the role of reactive power compensation equipment.

8.2 When the 1000kV bus voltage exceeds the allowable range, adjust the generator's reactive power output, reactive power compensation equipment, and the distribution of transformers.

Connect the switch to restore the voltage to the allowable range.

8.3 The reactive power output of generators connected to the 1000kV AC system, the reactive power compensation and voltage regulating equipment of 1000kV substations can be comprehensively implemented.

Combine optimization and real-time control to improve the operating voltage adjustment and control level.