ip-iq的改进算法与小波变换谐波检测方法研究

Research on improved ip-iq algorithm and Wavelet transform harmonic detection method

基于瞬时无功功率的理论的ip-iq的检测方法在三相电压不对称时提取基波有功功率时会产生误差的问题,为减小误差提出了一种新型ip-iq的检测方法代替正余弦发生器与锁相环部分。该方法直接将正序电压同步旋转到dq轴,并推导出正余弦分量,再与小波变换配合使用,减少小波变换单独使用时的混叠现象,得到更加准确的基波信号。在MATLAB软件中进行仿真实验,验证该方法的可行性。得到了用ip-iq的检测方法在三相电压不对称时a相基波与三相电压对称时波形大致重合,并小波变换减少了1.77%的基波含量。

The i_p-i_q detection method based on the theory of instantaneous reactive power will produce errors when extracting the fundamental active power when the three-phase voltage is asymmetric,and a new i_p-i_q detection method is proposed to replace the sine and cosine generator and phase lock ring part.This method directly rotates the positive sequence voltage to the dq axis and derives the sine and cosine components,and then works with the wavelet transform to reduce the aliasing phenomenon when the wavelet transform is used alone,so as to obtain more accurate fundamental wave signals.The feasibility of this method is verified by simulation experiment in MATLAB.The waveform of a phase basic wave coincides with that of three phase voltage symmetry using i_p-i_q detection method,and the content of basic wave is reduced by 1.77%by wavelet transform.