三相光伏逆变改进型AZSPWM3算法研究

Improved AZSPWM3 Algorithm for Three-phase Photovoltaic Inverters

针对三相光伏逆变系统的共模漏电流危害,提出一种改进的三段式等效零矢量脉宽调制(AZSPWM3)控制算法。该算法通过扩展载波周期,从而降低共模电压的脉动频率,可有效抑制逆变系统共模回路的谐振效应,减小系统对地共模漏电流。借助傅里叶级数推导、快速傅里叶变换(FFT)分析和Matlab电路仿真,研究了算法的工作特性。通过将其应用于三相逆变样机,实验验证了所提出的AZSPWM3控制算法在抑制共模干扰方面的可行性和有效性。

This paper proposes an improved active zero state pulse width modulation （AZSPWM3） algorithm to reduce the common mode leakage current in three-phase inverter system.By means of increasing the cycle of cartier wave, the frequency of common mode voltage can be reduced.Therefore, the resonance effect within common mode loop is diminished and the grounding leakage current is mitigated.The operational principle of the proposed algorithm is studied by Fourier derivation, fast Fourier transformation （FFT） analysis and Matlab simulation.Finally, a three-phase inverter prototype is built to testify the efficiency of the proposed algorithm.The experimental results are in good accordance with the simulation results.