CN-122026547-A - Low-voltage ride through control method, system, equipment and medium for doubly-fed fan

CN122026547ACN 122026547 ACN122026547 ACN 122026547ACN-122026547-A

Abstract

The application relates to the technical field of power grid regulation control, and discloses a low-voltage ride-through control method, a system, equipment and a medium for a doubly-fed fan, wherein the voltage of a grid-connected point of the doubly-fed fan is modeled based on the influence of a proportional error of voltage acquisition equipment and a direct current drift error of the voltage acquisition equipment adopted by the doubly-fed fan to the voltage of the grid-connected point, so as to obtain a theoretical measurement value of the voltage of the grid-connected point; the method comprises the steps of carrying out synchronous demodulation on a voltage theoretical measurement value of a grid-connected point to obtain a proportional error estimation value and a direct current drift error estimation value, carrying out error compensation on the voltage measurement value of the grid-connected point of a target doubly-fed fan according to the proportional error estimation value and the direct current drift error estimation value to obtain a compensated voltage measurement value of the grid-connected point, and controlling low-voltage ride through of the target doubly-fed fan according to the compensated voltage measurement value of the grid-connected point. The method of the application improves the accuracy of the voltage measurement of the grid-connected point and improves the low voltage ride through capability of the doubly-fed fan.

Inventors

ZHOU JINHUI
WANG DESHENG
HU YUNHAO
Chen Ningding
ZHOU SHUQING
JIN DONGHUI
DAI ZIBO

Assignees

国网浙江省电力有限公司瑞安市供电公司

Dates

Publication Date: 20260512
Application Date: 20260410

Claims (10)

1. The low-voltage ride through control method for the doubly-fed wind turbine is characterized by comprising the following steps of: modeling a grid-connected point voltage measured value of a target doubly-fed wind machine to obtain a grid-connected point voltage theoretical measured value, wherein the grid-connected point voltage theoretical measured value is set to reflect the influence of a direct current drift error of voltage acquisition equipment adopted by the target doubly-fed wind machine and a proportional error of the voltage acquisition equipment on the grid-connected point voltage; sequentially performing fundamental frequency voltage component conversion and double frequency voltage component conversion on the grid-connected point voltage theoretical measurement value output after phase locking processing, and sequentially performing band-pass filtering processing and low-pass filtering processing on the fundamental frequency voltage direct current component and the double frequency voltage direct current component obtained through conversion respectively to correspondingly obtain a direct current drift error estimation value and a proportional error estimation value; In the low voltage ride through control of the target doubly-fed wind machine, error compensation is carried out on the grid-connected point voltage measured value of the target doubly-fed wind machine according to the proportional error estimated value and the direct current drift error estimated value, and a compensated grid-connected point voltage measured value is obtained; And controlling the low-voltage ride through of the target doubly-fed fan according to the compensated grid-connected point voltage measured value.
2. The method for controlling low voltage ride through of a doubly-fed wind turbine according to claim 1, wherein modeling the measured value of the voltage at the grid-tie point of the target doubly-fed wind turbine to obtain the theoretical measured value of the voltage at the grid-tie point comprises: performing error analysis on voltage acquisition equipment adopted by a target doubly-fed fan to obtain an error term of the voltage acquisition equipment, wherein the error term comprises a proportional error and a direct current drift error; and modeling the grid-connected point voltage measured value of the target doubly-fed fan according to the proportional error and the direct current drift error to obtain a grid-connected point voltage theoretical measured value.
3. The method for controlling low voltage ride through of a doubly-fed wind turbine according to claim 1, wherein the sequentially performing fundamental frequency voltage component conversion and double frequency voltage component conversion on the theoretical measurement value of the grid-connected point voltage output after phase locking processing, and sequentially performing band-pass filtering processing and low-pass filtering processing on the fundamental frequency voltage direct current component and the double frequency voltage direct current component obtained by conversion respectively, correspondingly obtaining a direct current drift error estimated value and a proportional error estimated value, includes: Carrying out phase locking treatment and minimization treatment on the grid-connected point voltage theoretical measurement value in sequence to obtain a d-axis voltage theoretical measurement value of the grid-connected point voltage theoretical measurement value; analyzing the d-axis voltage theoretical measurement value, and determining a fundamental frequency voltage component introduced by the direct current drift error and a double frequency voltage component introduced by the proportion error in the d-axis voltage theoretical measurement value; determining a first voltage error handling factor for the fundamental frequency voltage component based on the fundamental frequency voltage component, determining a second voltage error handling factor for the doubled frequency voltage component based on the doubled frequency voltage component, the first voltage error handling factor being configured to convert the fundamental frequency voltage component to a direct current component, the second voltage error handling factor being configured to convert the doubled frequency voltage component to a direct current component; Carrying out data preprocessing on the fundamental frequency voltage component by adopting the first voltage error processing factor to obtain a fundamental frequency voltage direct current component of the grid-connected point voltage theoretical measurement value, and sequentially carrying out first band-pass filtering processing and first low-pass filtering processing on the fundamental frequency voltage direct current component to obtain a direct current drift error estimation value; and carrying out data preprocessing on the double-frequency voltage component by adopting the second voltage error processing factor to obtain a double-frequency voltage direct current component of the grid-connected point voltage theoretical measurement value, and sequentially carrying out second band-pass filtering processing and second low-pass filtering processing on the double-frequency voltage direct current component to obtain a proportional error estimated value.
4. The method of claim 3, wherein the first voltage error handling factor comprises And ; The second voltage error processing factor includes And 。
5. The method for controlling low voltage ride through of a doubly-fed wind turbine as claimed in claim 3, wherein said sequentially performing a first band-pass filtering process and a first low-pass filtering process on said dc component of said fundamental frequency voltage to obtain a dc drift error estimate comprises: performing first band-pass filtering processing on the direct current component of the fundamental frequency voltage to obtain a first signal to be subjected to low-pass filtering processing; performing first low-pass filtering processing on the first signal to be subjected to low-pass filtering processing to obtain an inter-phase direct current drift error difference value; Accumulating the inter-phase direct current drift error difference value by adopting a direct current drift error integral function to obtain an inter-phase direct current drift error difference value estimation value, wherein the direct current drift error integral function is used for enabling the inter-phase direct current drift error difference value to tend to be zero when converging; and obtaining a DC drift error estimated value according to the interphase DC drift error difference estimated value.
6. The method for controlling low voltage ride through of a doubly-fed wind turbine as claimed in claim 3, wherein said sequentially performing a second bandpass filtering process and a second lowpass filtering process on said two-frequency voltage dc component to obtain a proportional error estimate value includes: performing second band-pass filtering processing on the double-frequency voltage direct current component to obtain a second signal to be subjected to low-pass filtering processing; Performing second low-pass filtering processing on the second signal to be subjected to low-pass filtering processing to obtain an inter-phase proportional error difference value; accumulating the interphase proportional error difference value by adopting a proportional error integral function to obtain an interphase proportional error difference value estimation value, wherein the proportional error integral function is used for enabling the interphase proportional error difference value to be close to zero when converging; and obtaining a proportional error estimated value according to the interphase proportional error difference estimated value.
7. The method for controlling low voltage ride through of a doubly fed wind generator according to claim 5 or claim 6, wherein a center frequency of the first band-pass filtering process is a synchronous angular frequency of a power distribution network; And the center frequency of the second band-pass filtering treatment is 2 times of the synchronous angular frequency of the power distribution network.
8. The doubly-fed wind turbine low voltage ride through control system for realizing the doubly-fed wind turbine low voltage ride through control method according to any one of claims 1 to 7 is characterized by comprising a grid-connected point voltage modeling module, a synchronous demodulation module, an error compensation module and a low voltage ride through control module; The grid-connected point voltage modeling module is used for modeling a grid-connected point voltage measured value of a target doubly-fed wind machine to obtain a grid-connected point voltage theoretical measured value, and the grid-connected point voltage theoretical measured value is set to reflect the influence of a direct current drift error of voltage acquisition equipment adopted by the target doubly-fed wind machine and a proportion error of the voltage acquisition equipment on the grid-connected point voltage; The synchronous demodulation module is used for sequentially carrying out fundamental frequency voltage component conversion and double frequency voltage component conversion on the grid-connected point voltage theoretical measurement value which is output after phase locking processing, and sequentially carrying out band-pass filtering processing and low-pass filtering processing on the fundamental frequency voltage direct current component and the double frequency voltage direct current component which are obtained through conversion respectively, so as to correspondingly obtain a direct current drift error estimated value and a proportion error estimated value; The error compensation module is used for carrying out error compensation on the grid-connected point voltage measured value of the target doubly-fed fan according to the proportional error estimated value and the direct current drift error estimated value in low voltage ride through control of the target doubly-fed fan to obtain a compensated grid-connected point voltage measured value; The low voltage ride through control module is used for controlling the low voltage ride through of the target doubly-fed fan according to the compensated grid-connected point voltage measured value.
9. A computer device comprising a memory, a processor and a transceiver connected by a bus, the memory for storing a set of computer program instructions and data and for transmitting the stored data to the processor, the processor executing the computer program instructions stored by the memory for performing the doubly fed fan low voltage ride through control method of any one of claims 1 to 7.
10. A computer-readable storage medium, wherein a computer program is stored in the computer-readable storage medium, and when the computer program is executed, the low voltage ride through control method of the doubly-fed fan according to any one of claims 1 to 7 is implemented.

Description

Low-voltage ride through control method, system, equipment and medium for doubly-fed fan Technical Field The invention relates to the technical field of power grid regulation control, in particular to a low-voltage ride through control method, a system, equipment and a medium of a doubly-fed fan. Background Wind power generation is an important component of renewable energy, the installed capacity and the grid-connected scale of the wind power generation are continuously enlarged, and a doubly-fed induction wind power generator (hereinafter referred to as a doubly-fed fan) becomes one of the main models of wind power plants due to the advantages of speed change, constant frequency, flexible adjustment and the like. The voltage control characteristic and the low voltage ride through capability of the doubly-fed fan are key technical indexes for guaranteeing the safety and stability of the power grid, and when the voltage of the power grid fluctuates or a short circuit fault occurs, the doubly-fed fan needs to maintain the voltage stability of a grid-connected point through accurate voltage control, and keeps grid-connected operation within a specified time, so that the linkage accidents such as power grid frequency breakdown, voltage instability and the like caused by large-scale disconnection of the fan are avoided. The characteristic makes the regulation of the voltage of the grid-connected point extremely sensitive to reactive power, and the line voltage drop is mainly determined by the reactance voltage drop corresponding to the reactive power according to the voltage balance principle of the alternating current circuit, so that the doubly-fed fan needs to realize the voltage stabilization of the grid-connected point through accurate reactive power regulation, and the premise of the process is that the voltage signal of the grid-connected point is acquired and judged in a high precision manner. Currently, in low voltage ride through control of a doubly-fed wind turbine, the existing grid-connected point voltage measurement generally depends on a dq-axis transformation technology of a phase-locked loop to judge whether the grid-connected point voltage is lower than a low voltage ride through threshold, but due to a grid-connected point voltage measurement error, the phase tracking precision of the phase-locked loop is reduced, the dq-axis voltage component calculation is deviated, so that the state sensing capability of the controller on the grid-connected point voltage is reduced, the low voltage ride through capability of the doubly-fed wind turbine is obviously reduced, and the wind turbine is disconnected when serious, thereby affecting the safe and stable operation of a power grid. Therefore, how to improve the low voltage ride through capability of the doubly fed wind turbine has become a technical problem to be solved by those skilled in the art. Disclosure of Invention The invention provides a low-voltage ride-through control method, a system, equipment and a medium for a doubly-fed fan, which are used for solving the technical problem of how to improve the low-voltage ride-through capacity of the doubly-fed fan, realizing the effect of improving the accuracy of voltage measurement of grid-connected points and improving the low-voltage ride-through capacity of the doubly-fed fan. In a first aspect, the present invention provides a low voltage ride through control method for a doubly-fed wind turbine, the method comprising: modeling a grid-connected point voltage measured value of a target doubly-fed wind machine to obtain a grid-connected point voltage theoretical measured value, wherein the grid-connected point voltage theoretical measured value is set to reflect the influence of a direct current drift error of voltage acquisition equipment adopted by the target doubly-fed wind machine and a proportional error of the voltage acquisition equipment on the grid-connected point voltage; sequentially performing fundamental frequency voltage component conversion and double frequency voltage component conversion on the grid-connected point voltage theoretical measurement value output after phase locking processing, and sequentially performing band-pass filtering processing and low-pass filtering processing on the fundamental frequency voltage direct current component and the double frequency voltage direct current component obtained through conversion respectively to correspondingly obtain a direct current drift error estimation value and a proportional error estimation value; In the low voltage ride through control of the target doubly-fed wind machine, error compensation is carried out on the grid-connected point voltage measured value of the target doubly-fed wind machine according to the proportional error estimated value and the direct current drift error estimated value, and a compensated grid-connected point voltage measured value is obtained; And controlling the low-voltage ride through of the t