WO2023071266A1

WO2023071266A1 - Coordination control system for agc frequency modulation of energy storage participation unit of power plant

Info

Publication number: WO2023071266A1
Application number: PCT/CN2022/102518
Authority: WO
Inventors: 高峰; 兀鹏越; 孙钢虎; 柴琦; 王小辉; 寇水潮; 杨沛豪; 马晋辉; 张立松; 孙梦瑶; 郭新宇; 赵俊博
Original assignee: 西安热工研究院有限公司
Priority date: 2021-10-26
Filing date: 2022-06-29
Publication date: 2023-05-04
Also published as: CN113964850A

Abstract

The present disclosure provides a coordination control system for AGC frequency modulation of an energy storage participation unit of a power plant, comprising a 220 kV high-voltage bus, a main transformer, a voltage and current transmitter, a remote terminal unit (RTU), a generator voltage and current measuring device, a generator, a distributed control system (DCS), a high-voltage plant transformer, a 6 kV plant electric bus, a boosting transformer, an energy storage system voltage and current measuring device and an energy storage system.

Description

Coordinated Control System for Power Plant Energy Storage Participating in Unit AGC Frequency Modulation

Cross References to Related Applications

This application is based on a Chinese patent application with application number 202111249376.2 and a filing date of October 26, 2021, and claims the priority of this Chinese patent application. The entire content of this Chinese patent application is hereby incorporated by reference into this application.

technical field

The disclosure belongs to the field of unit frequency modulation in power plants, and in particular relates to a coordinated control system for power plant energy storage participating in unit AGC frequency modulation.

Background technique

With the increasing proportion of new energy, the pressure of wind power consumption will continue to increase, and the large-scale grid connection of wind power will significantly increase the AGC (Automatic Generation Control) frequency regulation demand of the grid. In addition, a large number of thermal power units undertake heavy AGC regulation tasks for a long time, resulting in a series of negative effects such as increased coal consumption for power generation and serious equipment wear and tear. Existing power frequency regulation resources can no longer meet the needs of large-scale grid-connected renewable energy. With economic development and the increase in the complexity of the power grid, this contradiction will become more prominent, affecting the safe and stable operation of the entire power grid.

The energy storage system controls the power of the energy storage device in real time through the control system, which has the advantages of fast response and precise control. Some thermal power plants are connected to the energy storage system, but it only assists the AGC frequency modulation of the unit, and there is no communication and coordination strategy with the unit, so that the energy storage system has too much or too little power to prevent Participating in AGC frequency modulation for a long time greatly reduces the frequency of use of the energy storage system.

Contents of the invention

The purpose of this disclosure is to provide a coordinated control system for power plant energy storage to participate in unit AGC frequency modulation for the existing energy storage auxiliary unit AGC frequency modulation system. The energy storage system cannot communicate with the unit for coordinated control. The system has a simple structure. The operation and maintenance cost of transformation is low, and the energy storage system and the generator set can cooperate with each other, which not only meets the AGC frequency regulation requirements, but also keeps the SOC of the energy storage system at about 50% for a long time, greatly improving the time for the energy storage system to participate in the AGC frequency regulation of the unit, and more To better meet the requirements of the grid assessment indicators and increase the economic benefits of power generation enterprises.

According to an embodiment of the present disclosure, a coordinated control system for power plant energy storage participating in unit AGC frequency modulation is provided, including a 220kV high-voltage bus, a main transformer, a voltage and current transmitter, a remote terminal unit RTU, a generator voltage and current measurement device, and a generator machine, distributed control system DCS, high-voltage factory transformer, 6kV factory power bus, step-up transformer, energy storage system voltage and current measurement device and energy storage system.

The generator is connected to the main transformer and the high-voltage service transformer through the generator voltage and current measuring device. The main transformer is connected to the 220kV high-voltage busbar through the first switch. The electric bus is connected to the high-voltage side of the step-up transformer through the third gate, and the low-voltage side of the step-up transformer is connected to the energy storage system through the voltage and current measuring device of the energy storage system.

The voltage and current transmitter is connected to the voltage and current measuring device of the generator, and the secondary voltage and current of the generator is drawn from the generator voltage and current measuring device to be connected to the voltage and current transmitter, and the connection between the distributed control system DCS and the voltage and current transmitter is established. The voltage and current transmitter transmits the voltage and current signals of the generator to the distributed control system DCS, and the distributed control system DCS calculates the power of the generator; the distributed control system DCS establishes a communication connection with the generator, and the distributed control system DCS sends AGC power commands to the generator; The distributed control system DCS and the energy storage system establish a two-way communication connection, the distributed control system DCS transmits the generator power signal to the energy storage system, and the energy storage system transmits the SOC signal of the energy storage system and the charging and discharging power of the energy storage system to the distributed control system DCS; The remote terminal unit RTU establishes a communication connection with the distributed control system DCS and the energy storage system, and the dispatching center transmits the AGC frequency modulation command to the distributed control system DCS and the energy storage system through the remote terminal unit RTU; the generator voltage and current measuring device, the energy storage system voltage and current The measuring device establishes a connection with the remote terminal unit RTU, and the voltage and current measuring device for the generator and the voltage and current measuring device for the energy storage system respectively connect the secondary voltage and current of the generator and the secondary voltage and current of the energy storage system to the remote terminal unit RTU, and the remote terminal unit The RTU collects and calculates the voltage and current to obtain the power of the generator and the power of the energy storage system. The remote terminal unit RTU transmits the sum of the power of the generator and the power of the energy storage system to the dispatch center.

In some embodiments, the energy storage system is physical energy storage, chemical energy storage or electromagnetic energy storage, and the energy storage system is used to absorb electric energy from the substation power system, and is used to send electric energy to the substation power system.

In some embodiments, the energy storage system is used to control the flow of its own power, and adjust the state and rate of charging and discharging of the energy storage system.

In some embodiments, the voltage and current transmitter collects the secondary voltage and current of the generator and converts it into a 4-20mA signal.

In some embodiments, when the unit is in normal operation and the energy storage system is in normal operation, the energy storage system is connected to the factory power system of the unit and participates in the AGC frequency modulation of the unit, and the first switch, the second switch and the third switch are in the closed position; the energy storage The system participates in unit AGC frequency modulation. The dispatching center sends AGC instructions to the distributed control system DCS and energy storage system through the remote terminal unit RTU. The distributed control system DCS sends AGC load instructions to the generator. The generator increases or decreases the power of the generator. The load command of the energy system is the difference between the AGC command and the power generated by the generator. When the load command of the energy storage system is positive, the energy storage system is in the discharge state; when the load command of the energy storage system is negative, the energy storage system is Charging status; the remote terminal unit RTU calculates the sum of the real-time power of the energy storage system and the real-time power of the generator and sends it to the dispatch center.

In some embodiments, when the output power of the energy storage system is 0 and the SOC of the energy storage system is lower than 50%, the generator increases the output power, and the increased power does not exceed the maximum charging power of the energy storage system, and the energy storage system enters charging state, the charging power is the difference between the generator power and the AGC command, until the SOC is equal to 50%, the generator returns to the power required by the AGC command, the energy storage system will not charge, and wait for the arrival of the next AGC command.

In some embodiments, when the output power of the energy storage system is 0 and the SOC of the energy storage system is higher than 50%, the generator reduces the output power, and the reduced power does not exceed the maximum discharge power of the energy storage system, and the energy storage system enters into discharge state, the discharge power is the difference between the AGC command and the generator power, until the SOC is equal to 50%, the generator recovers to the power required by the AGC command, the energy storage system will no longer discharge, and wait for the next AGC command to arrive.

In some embodiments, when the unit is running normally and the energy storage system is out of operation, the energy storage system is disconnected from the utility power system and does not participate in the AGC of the unit, the first switch and the second switch are in the closing position, and the third switch is in the dividing position The unit participates in AGC frequency regulation, and the dispatching center sends AGC commands to the distributed control system DCS through the remote terminal unit RTU, and the distributed control system DCS sends load increase and decrease commands to the generator, so that the load increase and decrease of the generator are always consistent with the load increase and decrease commands of the AGC .

The AGC frequency modulation system of the existing energy storage auxiliary unit, the unit DCS and the energy storage system have not established a communication link. When the energy storage system participates in the unit AGC frequency modulation, it cannot coordinate and control with the generator. The energy storage system can only cooperate with the generator for frequency regulation. The machine cannot cooperate with the energy storage to maintain a good SOC. The disclosure provides a coordinated control system for power plant energy storage participating in unit AGC frequency modulation. The energy storage system and DCS establish a communication link, which allows the energy storage system and the generator set to cooperate with each other, which not only meets the AGC frequency modulation requirements, but also makes the energy storage system The SOC is kept at about 50% for a long time, which greatly increases the time for the energy storage system to participate in the AGC frequency regulation of the unit, better meets the requirements of the grid assessment indicators, and increases the economic benefits of the power generation company.

Description of drawings

Fig. 1 is a schematic diagram of a coordinated control system for power plant energy storage participating in unit AGC frequency modulation provided according to an embodiment of the present disclosure.

Fig. 2 is a schematic diagram of the operation of a coordinated control system for power plant energy storage participating in unit AGC frequency modulation according to an embodiment of the present disclosure.

Fig. 3 is a schematic diagram of unit operation when the coordinated control system of power plant energy storage participating in unit AGC frequency modulation is shut down according to an embodiment of the present disclosure.

Explanation of reference signs:

1-220kV high-voltage busbar, 2-main transformer, 3-voltage and current transmitter, 4-remote terminal unit RTU, 5-generator voltage and current measuring device, 6-generator, 7-distributed control system DCS, 8-high voltage Plant transformer, 9-6kV plant power bus, 10-step-up transformer, 11-voltage and current measuring device for energy storage system, 12-energy storage system.

101-first switch, 201-second switch, 202-third switch.

Detailed ways

Embodiments of the present disclosure are described in detail below, examples of which are illustrated in the drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary only for explaining the present disclosure and should not be construed as limiting the present disclosure.

As shown in Figure 1, an embodiment of the present disclosure provides a coordinated control system for power plant energy storage participating in unit AGC frequency modulation, including 220kV high-voltage bus 1, main transformer 2, voltage and current transmitter 3, remote terminal unit RTU4, power generation Machine voltage and current measuring device 5, generator 6, distributed control system DCS7, high voltage plant transformer 8, 6kV plant power bus 9, step-up transformer 10, energy storage system voltage and current measuring device 11, energy storage system 12. Among them, the generator 6 is connected to the main transformer 2 and the high-voltage plant transformer 8 through the generator voltage and current measuring device 5, the main transformer 2 is connected to the 220kV high-voltage bus 1 through the first switch 101, and the high-voltage plant transformer 8 is connected to the second switch 201 It is connected to the 6kV substation power bus 9, the 6kV substation power bus 9 is connected to the high-voltage side of the step-up transformer 10 through the third gate 202, and the low-voltage side of the step-up transformer 10 is connected to the energy storage system 12 through the voltage and current measuring device 11 of the energy storage system .

In some embodiments, the energy storage system 12 is physical energy storage, chemical energy storage or electromagnetic energy storage, and the energy storage system 12 is used to absorb electric energy from the substation power system, and is used to send electric energy to the substation power system.

In some embodiments, the energy storage system 12 is used to control the flow of its own power, and adjust the state and rate of charging and discharging of the energy storage system.

In the coordinated control system of power plant energy storage participating in unit AGC frequency modulation provided by the embodiment of the present disclosure, the voltage and current transmitter 3 establishes a connection with the generator voltage and current measuring device 5, and the generator two leads out from the generator voltage and current measuring device 5. The secondary voltage and current is connected to the voltage and current transmitter 3, and the voltage and current transmitter 3 collects the secondary voltage and current of the generator and converts it into a 4-20mA signal. The distributed control system DCS7 establishes a connection with the voltage and current transmitter 3, and the voltage and current transmitter 3 transmits the voltage and current signals of the generator to the distributed control system DCS7, and the distributed control system DCS7 calculates the power of the generator. The distributed control system DCS7 establishes a communication connection with the generator 6, and the distributed control system DCS7 sends an AGC power command to the generator 6; the distributed control system DCS7 establishes a two-way communication connection with the energy storage system 12, and the distributed control system DCS7 transmits power generation to the energy storage system 12 The energy storage system 12 transmits the SOC signal of the energy storage system and the charging and discharging power of the energy storage system to the distributed control system DCS7. The remote terminal unit RTU4 establishes a communication connection with the distributed control system DCS7 and the energy storage system 12, and the dispatch center transmits AGC frequency modulation instructions to the distributed control system DCS7 and the energy storage system 12 through the remote terminal unit RTU4. The generator voltage and current measuring device 5, the energy storage system voltage and current measuring device 11 establish a connection with the remote terminal unit RTU4, and the generator voltage and current measuring device 5 and the energy storage system voltage and current measuring device 11 respectively measure the secondary voltage and current of the generator and the storage The secondary voltage and current of the energy system is connected to the remote terminal unit RTU4. The remote terminal unit RTU4 collects and calculates the voltage and current to obtain the power of the generator and the power of the energy storage system. The remote terminal unit RTU4 transmits the sum of the power of the generator and the power of the energy storage system to the dispatch center.

As shown in Figure 2, when the unit is in normal operation and the energy storage system is in normal operation, the energy storage system is connected to the factory power system of the unit and participates in the AGC frequency modulation of the unit, and the first switch 101, the second switch 201 and the third switch 202 are in the close position . The unit and the energy storage system participate in the AGC frequency regulation of the unit. The dispatching center sends an AGC command to the distributed control system DCS7 and the energy storage system 12 through the remote terminal unit RTU4. The distributed control system DCS7 sends an AGC load command to the generator 6, and the generator 6 increases or Reduce the power of the generator. The load command of the energy storage system is the difference between the AGC command and the power generated by the generator. When the load command of the energy storage system is positive, the energy storage system is in the discharge state, and when the load command of the energy storage system is negative In this case, the energy storage system is in a charging state. The remote terminal unit RTU4 calculates the sum of the real-time power of the energy storage system and the real-time power of the generator and sends it to the dispatch center. When the output power of the energy storage system is 0 and the SOC (state of charge) of the energy storage system is lower than 50%, the generator 6 increases the output power, and the increased power does not exceed the maximum charging power of the energy storage system, and the energy storage system starts charging state, the charging power is the difference between the generator power and the AGC command, until the SOC is greater than or equal to 50%, the generator 6 returns to the power required by the AGC command, the energy storage system will not charge, and wait for the next AGC command to arrive. When the output power of the energy storage system is 0 and the SOC of the energy storage system is higher than 50%, the generator 6 reduces the output power, and the reduced power does not exceed the maximum discharge power of the energy storage system, and the energy storage system enters the discharge state, and the discharge power is The difference between the AGC command and the power of the generator until the SOC is equal to 50%, the generator 6 recovers to the power required by the AGC command, and the energy storage system is no longer discharged, waiting for the arrival of the next AGC command.

As shown in Figure 3, the unit is running normally, and when the energy storage system is out of operation, the energy storage system is disconnected from the utility power system and does not participate in the AGC of the unit. The first switch 101 and the second switch 201 are closed, and the third switch 202 In the sub-position; the unit participates in AGC frequency regulation, and the dispatching center sends an AGC command to the distributed control system DCS7 via the remote terminal unit RTU4, and the distributed control system DCS7 sends a load increase or decrease command to the generator 6, so that the load increase or decrease of the generator 6 is always kept in line with the AGC The increase and decrease load commands are consistent.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present disclosure. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present disclosure have been shown and described, those skilled in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present disclosure. The scope of the present disclosure is defined by the claims and their equivalents.

Claims

A coordinated control system for power plant energy storage participating in unit AGC frequency modulation, including: 220kV high-voltage bus (1), main transformer (2), voltage and current transmitter (3), remote terminal unit RTU (4), generator voltage Current measuring device (5), generator (6), distributed control system DCS (7), high-voltage plant transformer (8), 6kV plant power busbar (9), step-up transformer (10), energy storage system voltage and current A measuring device (11) and an energy storage system (12); wherein,

The generator (6) is connected to the main transformer (2) and the high-voltage plant transformer (8) through the generator voltage and current measuring device (5), and the main transformer (2) is connected to the 220kV high-voltage busbar (1) through the first switch (101) connected, the high-voltage substation transformer (8) is connected to the 6kV substation power bus (9) through the second switch (201), and the 6kV substation power bus (9) is connected to the step-up transformer (10) through the third switch (202) The low-voltage side of the step-up transformer (10) is connected to the energy storage system (12) through the energy storage system voltage and current measuring device (11);

The voltage and current transmitter (3) establishes a connection with the generator voltage and current measuring device (5), and the secondary voltage and current of the generator is drawn out from the generator voltage and current measuring device (5) to be connected to the voltage and current transmitter (3). The control system DCS (7) establishes a connection with the voltage and current transmitter (3), and the voltage and current transmitter (3) transmits the voltage and current signals of the generator to the distributed control system DCS (7), and the distributed control system DCS (7) calculates output generator power; the distributed control system DCS (7) establishes a communication connection with the generator (6), and the distributed control system DCS (7) sends an AGC power command to the generator (6); the distributed control system DCS (7) and the energy storage system (12) Establish a two-way communication connection, the distributed control system DCS (7) transmits the generator power signal to the energy storage system (12), and the energy storage system (12) transmits the SOC signal of the energy storage system to the distributed control system DCS (7) and The charging and discharging power of the energy storage system; the remote terminal unit RTU (4) establishes a communication connection with the distributed control system DCS (7) and the energy storage system (12), and the dispatching center communicates with the distributed control system DCS (7) through the remote terminal unit RTU (4) ), the energy storage system (12) transmits the AGC frequency modulation command; the generator voltage and current measurement device (5), the energy storage system voltage and current measurement device (11) establishes a connection with the remote terminal unit RTU (4), and the generator voltage and current measurement device (5), the energy storage system voltage and current measuring device (11) respectively connects the secondary voltage and current of the generator and the secondary voltage and current of the energy storage system to the remote terminal unit RTU (4), and the remote terminal unit RTU (4) measures the voltage and current Collect and calculate to obtain the power of the generator and the power of the energy storage system, and the remote terminal unit RTU (4) transmits the sum of the power of the generator and the power of the energy storage system to the dispatching center.
The coordinated control system for power plant energy storage participating in unit AGC frequency modulation according to claim 1, wherein the energy storage system (12) is physical energy storage, chemical energy storage or electromagnetic energy storage, and the energy storage system (12) is used for The plant power system absorbs electric energy and is used to send electric energy to the plant power system.
According to claim 1 or 2, the coordinated control system for power plant energy storage participating in unit AGC frequency modulation, wherein the energy storage system (12) is used to control the flow direction of its own power, and adjust the state and rate of charging and discharging of the energy storage system.
According to any one of claims 1 to 3, the coordinated control system for power plant energy storage participating in unit AGC frequency modulation, wherein the voltage and current transmitter (3) collects the secondary voltage and current of the generator and converts it into a 4-20mA signal .
According to claim 1 or 2, the coordinated control system for power plant energy storage to participate in unit AGC frequency regulation, wherein, when the unit is in normal operation and the energy storage system is in normal operation, the energy storage system is connected to the power system of the unit and participates in unit AGC frequency regulation , the first switch (101), the second switch (201) and the third switch (202) are in the closed position; the energy storage system participates in the AGC frequency modulation of the unit, and the dispatching center sends a report to the distributed control system DCS (7 via the remote terminal unit RTU (4) ), the energy storage system (12) sends an AGC command, the distributed control system DCS (7) sends an AGC load command to the generator (6), the generator (6) increases or decreases the power of the generator, and the load command of the energy storage system is The difference between the AGC command and the power generated by the generator, when the load command of the energy storage system is positive, the energy storage system is in the discharge state, and when the load command of the energy storage system is negative, the energy storage system is in the charging state; the remote terminal The unit RTU (4) calculates the sum of the real-time power of the energy storage system and the real-time power of the generator (6) and sends it to the dispatch center.
According to claim 5, the coordinated control system of power plant energy storage participating in unit AGC frequency modulation, wherein, when the output electric energy of the energy storage system is 0 and the SOC of the energy storage system is lower than 50%, the generator (6) increases the output Power, increasing the power does not exceed the maximum charging power of the energy storage system, the energy storage system enters the charging state, the charging power is the difference between the generator power and the AGC command, until the SOC is equal to 50%, and the generator (6) returns to the AGC command required Power generation, the energy storage system is no longer charging, waiting for the arrival of the next AGC command.
According to claim 5, the coordinated control system of power plant energy storage participating in unit AGC frequency modulation, wherein, when the output electric energy of the energy storage system is 0 and the SOC of the energy storage system is higher than 50%, the generator (6) reduces the output Power, the reduced power does not exceed the maximum discharge power of the energy storage system, the energy storage system enters the discharge state, the discharge power is the difference between the AGC command and the generator power, until the SOC is equal to 50%, and the generator (6) returns to the AGC command required Power generation, energy storage system no longer discharge, waiting for the arrival of the next AGC instruction.
According to claim 5, the coordinated control system for power plant energy storage to participate in unit AGC frequency modulation, wherein, when the unit is running normally and the energy storage system is out of service, the energy storage system is disconnected from the plant power system and does not participate in the unit AGC. The first switch (101) and the second switch (201) are in the ON position, and the third switch (202) is in the OFF position; the unit participates in AGC frequency modulation, and the dispatching center sends a signal to the distributed control system DCS (7) via the remote terminal unit RTU (4) AGC command, the distributed control system DCS (7) sends a load increase or decrease command to the generator (6), so that the generator (6) load increase or decrease is always consistent with the AGC load increase or decrease command.