应用于频率宽范围偏移电网的改进相位差校正法

发布时间：2018-02-07 16:16

本文关键词： 谐波测量频率偏移非同步采样相位差法多项式变换　出处：《电力系统自动化》2017年23期 　论文类型：期刊论文

【摘要】：非同步采样造成的频谱泄漏是相位差测量误差的主要来源,尤其针对于频率宽范围偏移时,采用传统相位差法很可能造成测量失败。文中提出一种基于传统相位差的改进算法,改进算法分为两个步骤:第一,通过分析加窗信号频谱,将频谱表达式进行多项式变换从而加快旁瓣衰减速度,进一步减轻频谱泄漏和各谱线之间的干扰;第二,通过估计电网基波频率偏移范围确定待测信号采样点数,对采样序列采用截取点数不同的前后两次相位差法,第二次相位差法的截取点数由第一次相位差法估计的基波频率决定,减小了非同步采样带来的频谱泄漏。分别在基波频率稳定、基波频率宽范围偏移以及含有噪声干扰的情况下进行仿真验证。仿真结果表明,改进算法的电参数测量精度较传统相位差法有大幅度的提升,采样窗长满足IEC标准规定窗长。
[Abstract]:Spectrum leakage caused by asynchronous sampling is the main source of phase difference measurement error, especially when the frequency is wide range offset, the traditional phase difference method is likely to cause measurement failure. In this paper, an improved algorithm based on traditional phase difference is proposed. The improved algorithm is divided into two steps: first, by analyzing the windowed signal spectrum, the spectrum expression is transformed by polynomial to accelerate the sidelobe attenuation speed, further reduce the spectrum leakage and the interference between the spectral lines; second, The sampling points of the signal to be tested are determined by estimating the frequency offset range of the fundamental wave of the power network, and the sampling sequence is determined by two phase difference methods with different intercept points. The interception points of the second phase difference method are determined by the fundamental frequency estimated by the first phase difference method, which reduces the frequency leakage caused by asynchronous sampling. The simulation results show that the accuracy of the improved algorithm is much higher than that of the traditional phase difference method, and the sampling window length meets the IEC standard window length.
【作者单位】：浙江大学电气工程学院;
【分类号】：TM933.312

【相似文献】