抑制谐波的一个重要手段是采用有源电力滤波器,有源电力滤波器的工作性能很大程度上取决于对参考电流实时、准确地检测。首先阐述了基于瞬时无功功率的ip-iq法的谐波电流检测的基本原理,由于传统ip-iq法使用锁相环PLL和低通滤波器会使检测出来的参考电流存在相移偏差和时间延迟,提出了一种无锁相环ip-iq法来消除相移偏差,通过增加预置补偿角来消除低通滤波器产生的时间延迟,从而能够精确、实时地检测出谐波电流。理论分析、仿真结果验证了所提出的检测方法的可行性和有效性。 An important measure to suppress harmonics is the use of active power filters. The performance of active power filters largely depends on the real-time and accurate detection of reference currents. Firstly, the basic principle of harmonic current detection based on instantaneous reactive power of ip-iq method is expounded. Since the traditional ip-iq method uses the phase-locked loop PLL and the low-pass filter to make the detected reference current have the phase shift deviation and Time delay, a PLL-free ip-iq method is proposed to eliminate the phase-shift deviation and eliminate the time delay caused by low-pass filter by adding preset compensating angle so that the harmonic current can be detected precisely and in real time. Theoretical analysis and simulation results verify the feasibility and effectiveness of the proposed method.