Phasor measurement unit (PMU) measurement data-based power line parameter identification and estimation method

Abstract

The invention discloses a phasor measurement unit (PMU) measurement data-based power line parameter identification and estimation method, and belongs to the technical field of power system line parameter identification and estimation. The method comprises the following steps of: inputting basic data of an identified and estimated line by using a computer through a program, identifying error parameters of the line according to the PMU measurement data of multiple time intervals at two ends of the line, and estimating accurate parameters of the line to acquire estimation values of the accurate parameters of the line. A mean value-based identification index and parameter estimation method is constructed by using the PMU measurement data of multiple time intervals at two ends of the line, anda variance coefficient is used as a convergence precision criterion; and the method is simple, has good identification effect, high estimation precision and high calculation speed, and is convenient for popularization and application. The method can be widely applied to identification and estimation of the centralized parameters of the power line, the two ends of which are provided with PMUs; andthe method is particularly suitable for identification and estimation of the parameters of medium length high-voltage and ultrahigh-voltage power transmission lines.

Description

technical field [0001] The invention belongs to the technical field of line parameter identification and estimation in a power system, and in particular relates to a method for line parameter identification and estimation in a power system based on PMU (PhasorMeasurement Unit, phasor measurement unit) measurement data. Background technique [0002] The parameters of power grid equipment such as power lines and transformers are the basic data of the power grid. The accuracy of these parameters is directly related to the accuracy of various calculations and analyzes in power system planning and operation, especially the accuracy of power system state estimation and fault analysis, stability analysis, and online control and decision-making based on state estimation. have a significant impact on the availability of advanced applications such as Therefore, mastering accurate power grid equipment parameters is of great significance to ensure the safe and stable operation of the p...

AI Technical Summary

Problems solved by technology

The disadvantages of this method are: on the one hand, the D index cannot distinguish between parameter errors and measurement errors, and the D index still has numerical stability problems when the measured value is small; on the other hand, it is necessary to manually set the appropriate number of time periods when calculating the D index. , the D index corresponding to the number of different time periods has a large difference in value, which leads to misjudgment or missed judgment when using the value of the D index to judge whether there are wrong parameters

The main disadvantage of this method is that it also needs to manually set the number of time periods, and the parameter estimates corresponding to different time periods have large differences in value, which leads to unstable parameter estimation results.

In addition, another disadvantage of this method is that the wrong parameters are not identified but directly estimated, so the correct parameters may be estimated, resulting in a waste of computing resources and machine time

Images