谐波和无功电流检测方法分析

谐波、无功和负序电流的准确与快速检测是决定配电网静止同步补偿器性能的关键因素之一。文章对p-q法、ip-iq法、改进ip-iq法的检测性能进行了理论和仿真分析,并在TMS320LF2407A实验系统中对它们进行了实验研究。结果表明,只有当三相电压对称无畸变时,p-q法才能准确检测谐波、无功和负序电流分量;不管电网电压是否对称畸变,改进的ip-iq法都能精确检测正序基波有功电流,但计算量大;即使电网电压不对称且畸变,ip-iq法也能准确检测谐波电流,而对谐波、无功和负序电流的检测精度取决于锁相环对正序基波电压相位的检测精度,但该法的计算量小,更易于数字化实现。

Analysis of Harmonic and Reactive Currents Detection Method

The performance of distribution synchronous compensation（D-STATCOM） depends on the detecting accuracy and speed of the harmonic,reactive,and negative sequence current.In this paper,the detecting performance of p-q,ip-iq,and improved ip-iq method are analyzed theoretically and simulated.Meanwhile,their experimental study is implemented in the TMS320LF2407A system.The simulation and experimental results show that p-q method can exactly detect the harmonic,reactive,and negative sequence current only when the three-phase voltage is symmetrical and distortionless;the improved ip-iq method can exactly separate the fundamental positive sequence active current from the asymmetrical and distorting current whether the three-phase voltage is symmetrical and distorting,but its computation is very complicated;ip-iq method can exactly detect the harmonic current even the three-phase voltage is asymmetrical and distorting,and its computation is simpler and more easy to implemented in the fixed point DSP system compared with the improved ip-iq method,but it can not exactly separate the fundamental positive sequence active current from the asymmetrical and distorting current if the fundamental frequency of the line voltage can not been detected accurately.