用对称分量法检测间谐波背景下的基波分量

A Method to Detect Fundamental Component by Symmetrical Component under Inter-Harmonics

提出了一种间谐波背景下的基波检测对称分量法。该方法将三相含有间谐波分量的谐波电流信号在基波周期内对系统工频投影,获得基波分量和谐波分量,然后进行正、负、零序对称变换,从而实现基波分量和谐波分量的解耦, 并使用低通滤波器获得基波部分,最后再使用正、负、零序逆变换求得基波分量的瞬时值。该方法不受三相电流幅值及初相位不平衡、电压畸变、频率偏移的影响,具有各相独立的较好的抗干扰性能。仿真结果表明了该方法的有效性。

A method to detect fundamental component by symmetrical component under inter-harmonics is presented. In this method the three-phase harmonic current signals containing inter-harmonics is projected on system frequency within the period of fundamental component to obtain fundamental component and harmonic components, and symmetrical component transform of positive, negative and zero sequences are conducted to implement the decoupling of fundamental component and harmonic components, and then fundamental component can be obtained by low pass filter, finally the instantaneous value of fundamental component can be solved by inverse transformation of positive, negative and zero sequences. The presented method is not affected by such factors as the disequilibrium of both amplitudes and initial phase of three-phase currents, voltage distortion and frequency deviation, This method possesses better anti-interference performance which is independent for each phase. Simulation results show that the presented method is effective.