应用于频率宽范围波动电网的自适应采样相位差校正法

发布时间：2018-06-22 12:18

本文选题：谐波测量 + 频率波动　；参考：《电力系统自动化》2017年09期

【摘要】：指出了定速率采样下,非同步采样造成的频谱泄漏是相位差校正法测量误差的主要来源,尤其在对频率宽范围波动的电网信号进行连续测量时,采用相位差校正法可能造成测量失败。文中提出了一种基于自适应采样的改进方法。根据前次测得的基波频率与前次计算所得的频率变化率来预测电网的实时基波频率,并实时修正采样频率,使之跟踪变化的基波频率。分别在自适应采样与定速率采样下使用相位差校正法对频率动态变化的电网信号进行仿真对比。结果表明,该方法较定速率采样方法对同一变频电网信号的幅值测量精度提高一个数量级,相位测量精度提高3~14倍,采样窗长为IEC标准规定窗长的40%。该方法减小了因基波频率动态变化而产生的频谱泄漏,使相位差校正法在频率宽范围波动的电网中能够满足谐波连续测量的精度与实时性需要。
[Abstract]:It is pointed out that spectrum leakage caused by asynchronous sampling is the main source of measurement error of phase difference correction method under constant rate sampling, especially when continuous measurement of power network signals with wide frequency range is carried out. Phase difference correction may cause measurement failure. An improved method based on adaptive sampling is proposed. According to the measured fundamental frequency and the frequency change rate of the previous calculation, the real-time fundamental frequency of the power network is predicted, and the sampling frequency is corrected in real time to track the change of the fundamental frequency. The phase difference correction method is used to simulate and compare the frequency dynamic power network signals under adaptive sampling and constant rate sampling respectively. The results show that compared with the constant rate sampling method, the accuracy of amplitude measurement is increased by one order of magnitude, the accuracy of phase measurement is increased by 3n14 times, and the sampling window length is 40 times longer than that of IEC standard. This method can reduce the frequency leakage caused by the dynamic change of fundamental frequency and make the phase difference correction method meet the need of accuracy and real-time of harmonic continuous measurement in the power network with wide frequency fluctuation.
【作者单位】：浙江大学电气工程学院;
【分类号】：TM935

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