CN-121981596-A - Method and system for evaluating influence of voltage measurement error on grid-connected point voltage control

CN121981596ACN 121981596 ACN121981596 ACN 121981596ACN-121981596-A

Abstract

The invention relates to the technical field of grid-connected control, and provides a method and a system for evaluating the influence of voltage measurement errors on grid-connected point voltage control, wherein the method comprises the steps of obtaining a normal voltage output value sequence and a fault voltage output value sequence according to a static nonlinear error, a normal voltage measurement value sequence and a fault voltage measurement value sequence, and after the voltage deviation influence degree and the voltage unbalance influence degree are obtained through analyzing the grid-connected point positive sequence voltage amplitude and the grid-connected point negative sequence voltage amplitude obtained according to the normal voltage output value sequence, evaluating and analyzing the dynamic reactive power support influence degree obtained through analyzing the d-axis voltage measured value sequence obtained according to the fault voltage output value sequence and the dynamic response error analysis, and obtaining an influence evaluation result. The method can realize accurate evaluation of the voltage measurement error on the voltage control influence of the grid-connected point, and provide reliable theoretical basis and policy guidance for the selection, calibration and operation and maintenance of the voltage measurement equipment.

Inventors

ZHOU JINHUI
WANG DESHENG
HU YUNHAO
CHEN NINGTING
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: 20260505
Application Date: 20251231

Claims (10)

1. A method for evaluating the effect of voltage measurement errors on grid-connected point voltage control, the method comprising: Acquiring voltage measurement errors of a target evaluation scene and grid-connected point operation data to be analyzed, wherein the grid-connected point operation data to be analyzed comprises a normal voltage measurement value sequence and a fault voltage measurement value sequence; Carrying out true value analysis according to the static nonlinear error, the normal voltage measurement value sequence and the fault voltage measurement value sequence to obtain a normal voltage output value sequence and a fault voltage output value sequence; Analyzing the voltage deviation degree and the voltage unbalance degree according to the grid-connected point positive sequence voltage amplitude value and the grid-connected point negative sequence voltage amplitude value which are obtained based on the normal voltage output value sequence decomposition, and obtaining the voltage deviation influence degree and the voltage unbalance influence degree; D-axis voltage measurement value analysis is carried out according to the fault voltage output value sequence, the static nonlinear error and the dynamic response error, and dynamic reactive power support influence degree is obtained by analysis based on time multiplication absolute error integration criterion according to the obtained d-axis voltage measurement value sequence; And carrying out evaluation analysis according to the voltage deviation influence degree, the voltage unbalance influence degree and the dynamic reactive power support influence degree to obtain a corresponding influence evaluation result.
2. The method for evaluating voltage measurement errors affecting voltage control at a grid-tie point of claim 1, wherein said static nonlinear errors include DC drift and proportional errors, and wherein said step of obtaining a sequence of normal voltage output values and a sequence of fault voltage output values comprises: Calculating a corresponding normal voltage output value sequence based on a preset static voltage measurement error model according to the static nonlinear error and the normal voltage measurement value sequence, wherein the preset static voltage measurement error model is a linear relation model between a voltage measurement value and a voltage true value based on the static nonlinear error; and calculating a corresponding fault voltage output value sequence based on the preset static voltage measurement error model according to the static nonlinear error and the fault voltage measurement value sequence.
3. The method for evaluating the influence of voltage measurement errors on voltage control of grid-connected points according to claim 2, wherein the step of constructing the preset static voltage measurement error model comprises the following steps: scaling the voltage values of each phase in the voltage true values according to the corresponding scale error parameters in the scale errors to obtain scaled voltage true values; And adding corresponding fixed offsets to each phase voltage value in the scaled voltage true value according to each corresponding direct current drift parameter in the direct current drift to obtain the preset static voltage measurement error model.
4. The method for evaluating the effect of voltage measurement errors on grid-tie voltage control according to claim 1, wherein the step of obtaining the voltage deviation effect and the voltage imbalance effect comprises: performing voltage deviation degree analysis according to the grid-connected point positive sequence voltage amplitude, the reference grid-connected point positive sequence voltage amplitude and the preset phase voltage amplitude to obtain a first voltage deviation degree and a second voltage deviation degree, and obtaining the voltage deviation influence degree according to the difference value of the first voltage deviation degree and the second voltage deviation degree; And carrying out voltage unbalance analysis according to the grid-connected point positive sequence voltage amplitude, the grid-connected point negative sequence voltage amplitude, the reference grid-connected point positive sequence voltage amplitude and the corresponding reference grid-connected point negative sequence voltage amplitude to obtain a first voltage unbalance and a second voltage unbalance, and obtaining the voltage unbalance influence according to the difference value of the first voltage unbalance and the second voltage unbalance.
5. The method for evaluating voltage measurement errors on grid-connected point voltage control effects according to claim 1, wherein the static nonlinear errors comprise direct current drift and proportional errors, the dynamic response errors comprise settling time and measurement delay, and the step of analyzing d-axis voltage measurement values according to the fault voltage output value sequence, the static nonlinear errors and the dynamic response errors to obtain a d-axis voltage measurement value sequence comprises the steps of: performing phase-locked loop dq axis transformation on the fault voltage output value sequence to obtain a corresponding d-axis voltage component sequence; And according to the d-axis voltage component sequence, the static nonlinear error and the dynamic response error, carrying out voltage measurement value analysis based on a preset dynamic voltage measurement error model to obtain the d-axis voltage measurement value sequence, wherein the preset dynamic voltage measurement error model is a d-axis voltage measurement piecewise model taking the dynamic response error and the static nonlinear error into consideration.
6. The method for evaluating the voltage control influence of the voltage measurement error on the grid-connected point according to claim 5, wherein the grid-connected point operation data to be analyzed further comprises reactive support parameters, wherein the reactive support parameters comprise fault occurrence time, setting end time and fault end time; the preset dynamic voltage measurement error model comprises voltage measurement error submodels corresponding to a plurality of reactive support phases, wherein the reactive support phases are divided based on reactive support parameters, the reactive support phases sequentially comprise a measurement delay leading phase, a setting time leading phase and a static nonlinear error leading phase, the voltage measurement error submodels corresponding to the measurement delay leading phase are constructed based on static nonlinear errors and measurement delays, the voltage measurement error submodels corresponding to the setting time leading phase are constructed based on static nonlinear errors and dynamic response errors, and the voltage measurement error submodels corresponding to the static nonlinear error leading phase are constructed based on the static nonlinear errors; the d-axis voltage measurement sequence comprises a measurement delay dominant sequence, a setting time dominant sequence and a static nonlinear error dominant sequence.
7. The method for evaluating voltage measurement errors affecting voltage control at a grid-tie point according to claim 6, wherein said step of analyzing based on time-multiplied absolute error integration criteria based on the obtained d-axis voltage measurement sequence to obtain dynamic reactive support impact comprises: According to the measurement delay leading sequence and the corresponding measurement delay leading grid-connected point voltage reference value sequence, calculating to obtain corresponding first passive support influence degree based on a time-by-absolute error integration criterion; According to the setting time dominant sequence and the corresponding setting time dominant grid-connected point voltage reference value sequence, calculating to obtain a corresponding second reactive support influence degree based on a time-by-absolute error integration criterion; According to the static nonlinear error dominant sequence and the corresponding static nonlinear error dominant grid-connected point voltage reference value sequence, calculating based on a time-multiplied absolute error integral criterion to obtain a corresponding third reactive support influence; and accumulating the first reactive support influence degree, the second reactive support influence degree and the third reactive support influence degree to obtain the dynamic reactive support influence degree.
8. The method for evaluating the influence of voltage measurement errors on grid-connected point voltage control according to claim 1, wherein the step of evaluating and analyzing according to the voltage deviation influence degree, the voltage unbalance influence degree and the dynamic reactive support influence degree to obtain corresponding influence evaluation results comprises the following steps: When the dynamic reactive power support influence degree is not greater than a preset reactive power support threshold value and any one of the voltage deviation influence degree and the voltage unbalance influence degree is greater than a corresponding preset rated threshold value, setting the influence evaluation result as that the static nonlinear error of equipment measurement exceeds a standard; When the voltage deviation influence degree and the voltage unbalance influence degree are not larger than the corresponding preset rated threshold values and the dynamic reactive support influence degree is larger than the preset reactive support threshold value, setting the influence evaluation result as insufficient dynamic response of the equipment measurement link; And when any two of the voltage deviation influence degree, the voltage unbalance influence degree and the dynamic reactive power support influence degree exceed corresponding thresholds, setting the influence evaluation result as equipment disqualification.
9. The method for evaluating the influence of voltage measurement errors on grid-connected point voltage control according to claim 1, wherein the target evaluation scene comprises one of a device type selection scene and a device operation and maintenance scene; When the target evaluation scene is the equipment model selection scene, the voltage measurement error is obtained by equipment manufacturers of voltage measurement equipment; When the target evaluation scene is the equipment operation and maintenance scene, the voltage measurement error is obtained by building a simulation verification platform, wherein the voltage measurement equipment in the simulation verification platform is arranged in a test scene constructed by a voltage signal generator.
10. An evaluation system for voltage measurement error impact on grid-tie point voltage control, the system comprising: The system comprises a data acquisition module, a data analysis module and a data analysis module, wherein the data acquisition module is used for acquiring voltage measurement errors of a target evaluation scene and grid-connected point operation data to be analyzed, wherein the grid-connected point operation data to be analyzed comprises a normal voltage measurement value sequence and a fault voltage measurement value sequence; the data processing module is used for carrying out true value analysis according to the static nonlinear error, the normal voltage measurement value sequence and the fault voltage measurement value sequence to obtain a normal voltage output value sequence and a fault voltage output value sequence; the static index analysis module is used for analyzing the voltage deviation degree and the voltage unbalance degree according to the grid-connected point positive sequence voltage amplitude and the grid-connected point negative sequence voltage amplitude which are obtained based on the normal voltage output value sequence decomposition, so as to obtain the voltage deviation influence degree and the voltage unbalance influence degree; The dynamic index analysis module is used for carrying out d-axis voltage measurement value analysis according to the fault voltage output value sequence, the static nonlinear error and the dynamic response error, and carrying out analysis based on a time-multiplied absolute error integration criterion according to the obtained d-axis voltage measurement value sequence to obtain dynamic reactive support influence; and the comprehensive evaluation module is used for performing evaluation analysis according to the voltage deviation influence degree, the voltage unbalance influence degree and the dynamic reactive power support influence degree to obtain a corresponding influence evaluation result.

Description

Method and system for evaluating influence of voltage measurement error on grid-connected point voltage control Technical Field The invention relates to the technical field of grid-connected control, in particular to a method and a system for evaluating the influence of voltage measurement errors on grid-connected point voltage control. Background With large-scale access of high-proportion new energy into a power grid, the quantity of distributed power sources such as a doubly-fed fan and the like is increased sharply, the difference between the intensity and application scene of an access system is increased gradually, the variety of voltage measurement equipment is increased remarkably, the consistency of the equipment is reduced, and meanwhile, the output of the new energy is unstable, so that the voltage measurement environment is deteriorated. Based on the voltage drop sensing delay, the voltage drop sensing delay of the controller is caused by measurement delay and setting time, and the controller can acquire an offset voltage amplitude signal by static nonlinear errors, so that calculation of reactive current instructions is influenced, and voltage supporting capacity and grid connection stability of the fan are weakened. However, in the prior art, researches on voltage measurement errors are mainly focused on the equipment calibration level, static nonlinear error estimation usually only depends on manual reference signal injection, dynamic response error estimation usually only estimates or compares measurement delay through comparing differences between output and standard sources, and the two types of errors are calibrated for protection action criteria of power grid equipment, namely, the researches still stay in the error and measurement device, and quantization researches on the influence of voltage measurement errors on voltage control of a doubly fed fan grid connection point are not focused, in particular, analysis and evaluation on how the measurement errors cause additional voltage control deviation of the grid connection point are lacking. Therefore, the prior art cannot reflect the actual influence of dynamic and static composite errors in the dynamic voltage control of the fan, and is difficult to provide reliable theoretical basis and policy guidance for model selection, calibration and operation and maintenance of different voltage measurement devices in a distributed energy scene. Disclosure of Invention The invention aims to provide an evaluation method of voltage measurement errors on grid-connected point voltage control effects, which is based on an evaluation mechanism considering the influence of static nonlinear errors and dynamic response errors of voltage measurement on the grid-connected point voltage control effects, solves the problems of control distortion, incapability of quantifying coupling relations between errors and control effects and the like caused by neglecting the voltage measurement errors in the prior art, and simultaneously provides reliable technical support for voltage measurement equipment selection, calibration and operation and maintenance of a doubly-fed wind power plant. In order to achieve the above-mentioned object, it is necessary to provide a method and a system for evaluating the influence of a voltage measurement error on voltage control of a grid-connected point in order to solve the above-mentioned technical problems. In a first aspect, an embodiment of the present invention provides a method for evaluating an influence of a voltage measurement error on voltage control of a grid-connected point, where the method includes: Acquiring voltage measurement errors of a target evaluation scene and grid-connected point operation data to be analyzed, wherein the grid-connected point operation data to be analyzed comprises a normal voltage measurement value sequence and a fault voltage measurement value sequence; Carrying out true value analysis according to the static nonlinear error, the normal voltage measurement value sequence and the fault voltage measurement value sequence to obtain a normal voltage output value sequence and a fault voltage output value sequence; Analyzing the voltage deviation degree and the voltage unbalance degree according to the grid-connected point positive sequence voltage amplitude value and the grid-connected point negative sequence voltage amplitude value which are obtained based on the normal voltage output value sequence decomposition, and obtaining the voltage deviation influence degree and the voltage unbalance influence degree; D-axis voltage measurement value analysis is carried out according to the fault voltage output value sequence, the static nonlinear error and the dynamic response error, and dynamic reactive power support influence degree is obtained by analysis based on time multiplication absolute error integration criterion according to the obtained d-axis voltage measurement value sequence; And carrying