基于改进瞬时对称分量与三点算法的相量测量新算法

摘要

The real-time on-line estimation of phasor frequency, amplitude and phase angle makes a high request on both the accuracy and real-time of the method. In the conventional phasor measurement method based on DFT (discrete Fourier transform), data acquisition cycle is longer, and the accuracy is easy to be affected by the frequency fluctuation. On the other hand, while the systems are under unbalanced operation or unbalanced fault, positive and negative sequence components measurement is conducive to the dynamic analysis. This paper presents a method based on improved instantaneous symmetrical components and three-point algorithm for synchronized phasor measurement. Positive and negative sequence components instantaneous value can be obtained by instantaneous symmetrical components method, sequence components and fundamental wave can be detected, then the frequency, amplitude, and phase angle can be measured by the improved three-point method. This method is easy to be implemented, and has better real-time and higher measurement accuracy. The Matlab simulation results verify the correctness of the proposed method.%相量的频率、幅值和相角的实时在线估计需要算法在精度和实时性方面能够很好统一,传统DFT方法,数据采集周期较长,测量精度受系统频率波动的影响较大.另外,在系统发生不对称运行或不对称故障时,对电量的正负序分量测量有利于动态分析.针对这些问题,提出了一种基于改进瞬时对称分量法与三点算法相结合的相量测量算法.该算法利用瞬时对称分量法获取电量各个序分量的瞬时值,并进行基波正、负序电量的检测,然后利用改进三点法对基波量进行频率、幅值和相角的计算,它易于实现、实时性好、精度相对较高.通过Matlab进行仿真验证,结果表明所提方法在实时性和精度方面能够得到较好统一.