A novel reduced leakage current modulation technique for Z-source inverter used in photovoltaic systems

Abstract

In this study a novel modulation technique is proposed to reduce common mode leakage current in a three-phase Z-Source inverter used in a photovoltaic (PV) system. The proposed method reduces common mode current as well as common mode voltage (CMV); moreover, it reduces inverter output current total harmonic distortion at high switching frequencies. At first, previously presented techniques are summarised. Then, proposed technique is presented theoretically. Finally, conventional space vector modulation and the proposed modulation technique are simulated for a 10 kW PV power generation system. The validity of the proposed modulation technique is verified through MATLAB/Simulink. Simulations are performed for different load power factors and switching frequencies with considering real application parameters to provide a certain comparison between conventional and proposed modulation techniques. The results are analysed considering both CMV, leakage current and inverter output current quality, and the results verify effectiveness of the proposed technique.