The paper introduced basic theory of ip-iq method based on instantaneous reactive power theory, and pointed out that there is error of amplitude and phase of active current component of fundamental wave detected by traditional ip-iq method because of phase difference between power grid voltage and its positive-sequence component. It proposed an improved ip-iq harmonic detection method. The improved method acquires synchronous rotation signal through combining positive-sequence voltage components with phase shift operator, which reduces detection error caused by three-phase voltage asymmetry, and introduces current mean value theory to replace low-pass filter, so as to improve dynamic response capability of harmonic detection. The Matlab simulation results showed the improved method can detect positive-sequence active current of fundamental wave correctly under condition of three-phase voltage asymmetry and has good dynamic response performance.%介绍了基于瞬时无功功率理论的ip-iq法的基本原理,指出传统ip-iq法检测到的基波有功电流分量的幅值和相位因电网电压与其正序分量的相位差而存在误差；提出一种改进型ip-iq谐波检测法,该方法通过正序电压分量和移相算子相结合的方式获取同步旋转信号,减小了因三相电压不对称而导致的检测误差,同时引入电流平均值理论以取代低通滤波器,提高了谐波检测的动态响应能力.Matlab仿真结果表明,该检测法在三相电网电压不对称的情况下能准确检测到基波正序有功电流,且具有较好的动态响应特性.
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