CN-121840676-B - District voltage compensation control method and system considering distributed power supply fluctuation

CN121840676BCN 121840676 BCN121840676 BCN 121840676BCN-121840676-B

Abstract

The application relates to the technical field of power distribution system control, in particular to a method and a system for controlling the voltage compensation of a transformer area taking distributed power supply fluctuation into consideration, which comprises the steps of constructing the power quality influence coefficient of each transformer area in each time period according to the data change of each transformer area in the voltage data rotation component of each time period and the difference condition among positive sequence, negative sequence and zero sequence components obtained by three-phase voltage decomposition, calculating the comprehensive disturbance coefficient of the low-voltage transformer area in each time period by combining the voltage difference and the voltage change trend synchronism among different transformer areas, comprehensively considering the distribution difference and the coupling influence relation among the transformer areas, and more accurately evaluating the influence characteristics of the distributed power supply fluctuation; and optimizing the gain coefficient in the synovial membrane controller based on the obtained comprehensive disturbance coefficient, and performing the transformer area voltage compensation control by adopting the adjusted controller, thereby being beneficial to overcoming the defect of insufficient voltage compensation precision and reliability of the transformer area.

Inventors

SUN WENJIE
ZHENG SHIMIN
ZHENG SHUBAO
YANG JINNIAN
CHENG XUEFENG
CHEN BING
SUN JIE
LI JITAO
BIAN JING
QIN KEWEI

Assignees

国网黑龙江省电力有限公司齐齐哈尔供电公司

Dates

Publication Date: 20260512
Application Date: 20260311

Claims (7)

1. The method for controlling the voltage compensation of the transformer area by considering the fluctuation of the distributed power supply is characterized by comprising the following steps: three-phase voltage data of each grid-connected point of the low-voltage transformer area are collected in real time; The method comprises the steps of adopting an inherent time scale decomposition technology to decompose signals of single-phase voltage data of grid-connected points in each period, adopting a symmetrical component method to decompose three-phase voltage of the grid-connected points in each period, adopting a data change maximum value point to divide each rotation component obtained by the signal decomposition, respectively analyzing the difference degree between two parts of data obtained by dividing in each rotation component and the difference condition between three components obtained by decomposing by the symmetrical component method, and determining the electric energy quality influence coefficient of the three-phase voltage data of the grid-connected points in each period; Constructing coupling influence degree values of the grid-connected points in each time period based on the difference condition of the voltage per unit values among different grid-connected points in each time period and the voltage data change trend synchronization condition, and calculating the comprehensive disturbance coefficients of the low-voltage transformer areas in each time period by combining the electric energy quality influence coefficients; Adjusting the gain coefficient of the controller based on the comprehensive disturbance coefficient, and carrying out district voltage compensation control by adopting the adjusted controller; The acquisition process of the electric energy quality influence coefficient comprises the following steps: calculating the difference between the average value of the two data obtained by dividing in each rotating component and marking the difference as a first difference, determining the middle-low frequency component in the rotating component, and marking the fusion value of the first difference of all the middle-low frequency components of the single-phase voltage of each grid-connected point in each period as a voltage sag characteristic significant coefficient; Constructing unbalanced significant values of three-phase voltages of each grid-connected point in each period based on the difference conditions among modes of three components obtained by decomposition by a symmetrical component method; determining the electric energy quality influence coefficient of three-phase voltage data of each grid-connected point in each period based on the voltage sag characteristic significant coefficient and the unbalance significant value, wherein the electric energy quality influence coefficient respectively has positive correlation with the voltage sag characteristic significant coefficient and the unbalance significant value; the coupling influence degree value is obtained through the following steps: Calculating the voltage deviation degree of each grid-connected point in each period based on the voltage per unit value difference condition between each grid-connected point and other grid-connected points in each period; determining the coupling influence degree value of each grid-connected point in each period based on the voltage deviation degree and the correlation coefficient; the expression for adjusting the gain coefficient of the controller based on the comprehensive disturbance coefficient is as follows: ; Where P is the adjusted gain factor, 、 And R is the average value of the normalized values of the comprehensive disturbance coefficients of all the time periods in the preset current detection window.
2. The method for controlling the voltage compensation of a station area in consideration of distributed power supply fluctuation as set forth in claim 1, wherein the process of obtaining the imbalance significant value is as follows: And respectively calculating the difference between the modulus of the negative sequence component and the modulus of the positive sequence component and the difference between the modulus of the zero sequence component and the modulus of the positive sequence component in three components obtained by the symmetrical component decomposition, and averaging the two to obtain the unbalance significant value.
3. The method for controlling the voltage compensation of a station area taking distributed power supply fluctuation into consideration as set forth in claim 1, wherein the step of obtaining the voltage deviation degree is: calculating the average value of the per-unit voltage values at all moments of each grid-connected point in each period, and calculating the difference between the average value of the per-unit voltage values of each grid-connected point and each other grid-connected point in each period, wherein the difference is marked as a second difference; the voltage deviation degree of each grid-connected point in each period is the average value of all the second differences of each grid-connected point in each period.
4. The method of claim 1, wherein the coupling influence level value has a positive correlation with the voltage deviation level and the correlation coefficient, respectively.
5. The method for controlling voltage compensation of a power distribution area according to claim 1, wherein the integrated disturbance factor is in positive correlation with the coupling influence degree value and the power quality influence factor of all the grid-connected points in the power distribution area in each period.
6. The method for controlling the voltage compensation of the district taking the fluctuation of the distributed power supply into consideration as set forth in claim 1, wherein the process of controlling the voltage compensation of the district by using the adjusted controller is as follows: Calculating power factors of the station areas in each preset detection window, and if the power factors obtained in the current detection window are lower than a preset threshold value or the per-unit value of the voltage of any one of the station areas at the current moment exceeds a preset safety range, taking the adjusted gain coefficient of the current detection window as the gain coefficient of a controller in the next detection window, and performing compensation control on the voltage of the station areas.
7. A district voltage compensation control system taking into account distributed power supply fluctuations, comprising a memory, a processor and a computer program stored in said memory and running on said processor, characterized in that said processor implements the steps of the method according to any of claims 1-6 when said computer program is executed.

Description

District voltage compensation control method and system considering distributed power supply fluctuation Technical Field The application relates to the technical field of power distribution system control, in particular to a method and a system for controlling transformer area voltage compensation by considering distributed power supply fluctuation. Background With the construction and development of new power distribution systems, the large-scale application of distributed power sources and energy storage has become a necessary trend. The distribution transformer area is a basic unit for low-voltage distribution management, line loss accounting and user service of the power system, and the electric energy quality is easily deteriorated due to the continuous increase of the access scale of various distributed power supplies and nonlinear loads, so that the safe operation of electric equipment is affected. To cope with this problem, reactive and active regulation of a power flow controller (RPC) or grid-connected inverter is generally used to perform district voltage compensation, so as to ensure voltage stabilization of voltage users. Considering that the output of the distributed power supply has obvious intermittence and fluctuation, the rapid change of the output power can directly lead to rapid fluctuation and out-of-limit of the voltage along the parallel network and the station area, especially in a low-voltage distribution station area with high impedance, the influence is more sensitive and severe, and meanwhile, stronger uncertainty exists. In addition, the strong electrical coupling between multiple parallel nodes, the compensation action of a single node can interfere with the voltages of other nodes, and control conflict or oscillation is easy to cause. The traditional voltage control means are difficult to adapt to the characteristics of nonlinearity, coupling and the like of a power grid, and under the influence of the factors, the defects of insufficient voltage compensation precision and reliability of a transformer area are easy to exist. Disclosure of Invention In order to solve the technical problems, the application aims to provide a method and a system for controlling the voltage compensation of a platform area by considering the fluctuation of a distributed power supply, wherein the adopted technical scheme is as follows: In a first aspect, an embodiment of the present application provides a method for controlling voltage compensation of a bay in consideration of distributed power supply fluctuation, the method including the steps of: three-phase voltage data of each grid-connected point of the low-voltage transformer area are collected in real time; The method comprises the steps of adopting an inherent time scale decomposition technology to decompose signals of single-phase voltage data of grid-connected points in each period, adopting a symmetrical component method to decompose three-phase voltage of the grid-connected points in each period, adopting a data change maximum value point to divide each rotation component obtained by the signal decomposition, respectively analyzing the difference degree between two parts of data obtained by dividing in each rotation component and the difference condition between three components obtained by decomposing by the symmetrical component method, and determining the electric energy quality influence coefficient of the three-phase voltage data of the grid-connected points in each period; Constructing coupling influence degree values of the grid-connected points in each time period based on the difference condition of the voltage per unit values among different grid-connected points in each time period and the voltage data change trend synchronization condition, and calculating the comprehensive disturbance coefficients of the low-voltage transformer areas in each time period by combining the electric energy quality influence coefficients; And adjusting the gain coefficient of the controller based on the comprehensive disturbance coefficient, and carrying out district voltage compensation control by adopting the adjusted controller. In one embodiment, the process of obtaining the power quality influence coefficient is: calculating the difference between the average value of the two data obtained by dividing in each rotating component and marking the difference as a first difference, determining the middle-low frequency component in the rotating component, and marking the fusion value of the first difference of all the middle-low frequency components of the single-phase voltage of each grid-connected point in each period as a voltage sag characteristic significant coefficient; Constructing unbalanced significant values of three-phase voltages of each grid-connected point in each period based on the difference conditions among modes of three components obtained by decomposition by a symmetrical component method; And determining the electric energy q