CN-122026436-A - Active control method, system and medium for energy storage power station combining inertia and sagging characteristics

CN122026436ACN 122026436 ACN122026436 ACN 122026436ACN-122026436-A

Abstract

The invention discloses an active control method of an energy storage power station combining inertia and sagging characteristics, which comprises the steps of establishing a mathematical model of an inverter circuit in the energy storage power station according to an electromagnetic characteristic equation of a synchronous generator, calculating output power of the energy storage power station according to the mathematical model, calculating the output power according to sagging characteristics to obtain a voltage reference value of output voltage of the inverter circuit, calculating a voltage difference value, calculating a grid-connected current reference value according to the voltage difference value, obtaining a reference modulation voltage wave according to an actual value of the grid-connected current and the grid-connected current reference value, and modulating the voltage wave of the energy storage power station by the reference modulation voltage wave to realize balance of three-phase grid-connected current. According to the method, a mathematical model of the energy storage converter is established by simulating a characteristic equation of the synchronous generator, and an active and reactive control outer ring and a voltage and current control inner ring are designed, so that the energy storage power station can realize self-synchronization grid connection while having the external characteristic of a voltage source, and provide voltage and frequency support for a power grid when necessary.

Inventors

LIU TINGXIANG
WANG ZIMING
ZHOU WANPENG
WANG KAI
AN NA
CAO ZHIMEI
XU HUI
ZHANG YONGXIN

Assignees

国网青海省电力公司经济技术研究院
国网青海省电力公司清洁能源发展研究院

Dates

Publication Date: 20260512
Application Date: 20251201

Claims (10)

1. An energy storage power station active control method combining inertia and sagging characteristics is characterized by comprising the following steps: Establishing a mathematical model of an inverter circuit in the energy storage power station according to an electromagnetic characteristic equation of the synchronous generator; calculating the output power of the energy storage power station according to the mathematical model, wherein the output power comprises active power and reactive power; Calculating the output power according to the sagging characteristic to obtain a voltage reference value of the output voltage of the inverter circuit; calculating a voltage difference value according to the voltage reference value and the voltage value of the grid-connected point, and calculating a grid-connected current reference value according to the voltage difference value; And obtaining a reference modulation voltage wave of the grid-connected current reference value according to the actual value of the grid-connected current and the calculation, wherein the reference modulation voltage wave is used for modulating the voltage wave of the energy storage power station so as to realize the balance of three-phase grid-connected current.
2. The method of claim 1, wherein the mathematical model is: ; Wherein, the Is the bridge arm side voltage of the inverter, For the output voltage of the inverter, L is the reactance, The output current of the inverter is represented by R, which is the internal resistance.
3. The method of claim 2, wherein the calculation formula for calculating the output power of the energy storage power station from the mathematical model is: ; Wherein P is the active power of the energy storage power station, Q is the reactive power of the energy storage power station, 、、 Respectively are at corresponding electric potential 、、 Is used for the phase voltage of the (c) transformer, 、、 Respectively are at corresponding electric potential 、、 Phase currents of (a) are provided.
4. The method according to claim 1, wherein the calculating the output power according to the droop characteristic to obtain the voltage reference value of the output voltage of the inverter circuit specifically includes: obtaining a first instruction value of the phase angle of the output voltage through active power according to the sagging characteristic, and reversely adjusting the phase angle of the output voltage by using the first instruction value to obtain the phase angle of the reference voltage; Obtaining a second instruction value of the amplitude of the output voltage through reactive power according to the sagging characteristic, and reversely adjusting the amplitude of the output voltage by using the second instruction value to obtain the amplitude of the reference voltage; and obtaining a voltage reference value of the output voltage of the inverter circuit according to the phase angle of the reference voltage and the amplitude value of the reference voltage.
5. The method of claim 4, wherein the calculation formula for obtaining the voltage reference value of the inverter circuit output voltage according to the phase angle of the reference voltage and the amplitude of the reference voltage is: ; ; Wherein, the For the purpose of synthesizing the magnitude of the potential, For the no-load potential to be present, In order to be a voltage regulation factor, For the reactive power adjustment factor, As a reference value for the reactive power, As a value of the reactive power output, For the phase angle of the light, As a reference value for the voltage, the reference value, Is the voltage output value.
6. The method according to claim 5, wherein calculating a voltage difference value from the voltage reference value and a voltage value of a grid-connected point, and calculating a grid-connected current reference value from the voltage difference value, comprises: taking the voltage feedback value of the inverter circuit as the voltage value of the grid-connected point; calculating a voltage difference value between the voltage reference value and the voltage feedback value; and calculating a grid-connected current reference value by using the voltage difference value and the virtual impedance.
7. The method according to claim 6, wherein the calculating the reference value of the grid-connected current according to the actual value of the grid-connected current and the calculated reference value of the grid-connected current specifically comprises: Calculating a current difference value between the grid-connected current reference value and the grid-connected current actual value; A reference modulated voltage wave is obtained using a quasi-PR regulator based on the current difference.
8. An energy storage plant active control system combining inertial and droop characteristics for implementing the method of any one of claims 1-7, the system comprising: The model building module is used for building a mathematical model of the inverter circuit in the energy storage power station according to an electromagnetic characteristic equation of the synchronous generator; the first calculation module is used for calculating the output power of the energy storage power station according to the mathematical model, wherein the output power comprises active power and reactive power; the second calculation module is used for calculating the output power according to the sagging characteristic to obtain a voltage reference value of the output voltage of the inverter circuit; The third calculation module is used for calculating a voltage difference value according to the voltage reference value and the voltage value of the grid-connected point and calculating a grid-connected current reference value according to the voltage difference value; the modulation module is used for obtaining a reference modulation voltage wave of the grid-connected current reference value according to the grid-connected current actual value and the calculated value, and the reference modulation voltage wave is used for modulating the voltage wave of the energy storage power station so as to realize balance of three-phase grid-connected current.
9. An electronic device comprising a processor, an input device, an output device and a memory, the processor, the input device, the output device and the memory being interconnected, the memory being for storing a computer program comprising program instructions, characterized in that the processor is configured to invoke the program instructions to perform the method according to any of claims 1-7.
10. A computer readable storage medium, characterized in that the computer readable storage medium stores a computer program comprising program instructions which, when executed by a processor, cause the processor to perform the method of any of claims 1-7.

Description

Active control method, system and medium for energy storage power station combining inertia and sagging characteristics Technical Field The invention relates to the technical field of power systems, in particular to an active control method, an active control system, active control equipment and active control media for an energy storage power station by combining inertia and sagging characteristics. Background With the aggravation of energy crisis, various new energy sources such as wind energy, solar energy, fuel cells and other power generation systems are widely used. In a high-power wind power generation system, an energy storage converter is an important link for realizing electric energy feedback to a power grid, and the control performance of the current at the side of the converter network directly determines the advantages and disadvantages of the system performance. The control strategy of the energy storage converter is the key of grid-connected control, and a grid-side DC-AC conversion unit is required for any new energy grid-connected power generation system. Active and reactive power control of the grid-connected inverter can be realized by controlling the output current vector of the energy storage converter, and the grid-connected control method is actually used for indirectly controlling the output current vector through the alternating-current side voltage vector of the energy storage converter, so that the method is called indirect current control. The indirect current control method does not need current detection and is simple to control, but the control method is sensitive to system parameter change, the dynamic response speed is low because the control is performed based on a steady-state model of the system, and the waveform quality of the output current of the energy storage converter is difficult to guarantee because of no current feedback control. Because of the defect of indirect current control, the direct current control scheme is adopted in the prior art, and the active current and the reactive current of the energy storage current transformer can be controlled by controlling the amplitude of the output current vector of the energy storage current transformer and the phase relative to the voltage vector of the power grid, so that the control of the energy storage current transformer is realized. In a grid-connected system, the total harmonic distortion rate of grid-connected current is required to be small enough for the harmonic of the grid-connected current of the energy storage converter, so that the output filtering of the energy storage converter is particularly important, and in the prior art, a resonance peak exists in the amplitude-frequency characteristic of an output filter of the energy storage converter, so that the control stability of the energy storage converter is reduced, and the energy storage converter oscillates. Disclosure of Invention The invention aims to provide an active control method, an active control system, active control equipment and an active control medium for an energy storage power station, which combine inertia and sagging characteristics, and solve the technical problems in the prior art. The invention is realized by the following technical scheme: In a first aspect, a method for actively controlling an energy storage power station according to a first embodiment of the present invention includes: Establishing a mathematical model of an inverter circuit in the energy storage power station according to an electromagnetic characteristic equation of the synchronous generator; calculating the output power of the energy storage power station according to the mathematical model, wherein the output power comprises active power and reactive power; Calculating the output power according to the sagging characteristic to obtain a voltage reference value of the output voltage of the inverter circuit; calculating a voltage difference value according to the voltage reference value and the voltage value of the grid-connected point, and calculating a grid-connected current reference value according to the voltage difference value; And obtaining a reference modulation voltage wave of the grid-connected current reference value according to the actual value of the grid-connected current and the calculation, wherein the reference modulation voltage wave is used for modulating the voltage wave of the energy storage power station so as to realize the balance of three-phase grid-connected current. Further, the mathematical model is: ; Wherein, the Is the bridge arm side voltage of the inverter,For the output voltage of the inverter, L is the reactance,The output current of the inverter is represented by R, which is the internal resistance. Further, a calculation formula for calculating the output power of the energy storage power station according to the mathematical model is as follows: ; Wherein P is the active power of the energy storage power station, Q is