利用故障录波数据修正PMU数据中电压相角差误差的方法

Method for Correcting Errors of Voltage Phase Angle Difference Measured in PMU by Using Fault Recorder Data

实际电网频率的波动性会使PMU中利用DFT算法计算电压相角时出现误差,另外由于实际电网中缺乏其他测量电压相角差的手段,导致在实际电网中无法实现对PMU测量的不同测点上的电压相角差数据误差进行校验,因此本文提出了一种利用故障录波器上传的电压波形数据计算不同测点上电压相角差的方法,利用单相接地故障时的零序电流波形和相关函数分析,实现了线路两端录波数据的同步,并计算出了线路两端不同测点间的电压相角差。理论分析、实际PMU数据和录波数据的分析结果表明:该方法实现了电网中不同测点上电压相量间相角差的准确测量,实现了对利用PMU测量相角数据计算的电压相角差误差的修正。该方法对于提高故障录波数据的应用价值和修正PMU数据中的电压相量相角差的误差具有重要参考价值。

The voltage phase angle calculated by using DFT algorithm in phasor measurement unit( PMU) contains large errors because of the volatility of the actual power grid frequency. For lacking of the other method in real power grid to measure the phase angle difference,it is impossible to verify the error of phase angle difference measured by PM U. The voltage phase angle difference between different measuring points has not been obtained accurately in actual power grid. This paper presents a method to calculate the phase angle difference of voltage at different measuring points using the voltage waveform data uploaded by the fault recorder. The synchronization of the recorded data measured at different substation is realized by using the zero-sequence-current waveform at the time of single-phase earth fault,and the voltage phase angle difference between different measuring points is calculated by the correlation function. The results of theoretical analysis and actual data analysis showthat the accurate voltage phase angle difference at different measurement points of power grid is accurately obtained by this method. With the calculation results of this method,it is possible to modify the measurement error of the voltage phase angle difference calculated by PM U. This method is important to analyze the measurement accuracy of voltage phase angle difference between voltage phasors at different nodes of power grid and improve the value of fault recorder data.