Hysteresis Current Controlled Single phase Grid-Connected PV Inverter System with LCL Filter

Single phase hysteresis current controllers have traditionally been implemented using two level

This paper presents a simple, low cost, and effective technique to allow single phase hysteresis current regulation to be implemented as three level modulation process. This achieves a substantial reduction in the magnitude and variation of the switching frequency, thus improving efficiency, while retaining all of the advantages identified with hysteresis current control. LCL filters have good performances in current ripple attenuations, but they introduce a resonance frequency in the system. The operation and control of the inverter are described, together with simulation and experimental results. The proposed controller has been verified in simulation using the Simulink package in Matlab. An analysis and design procedure of output LCL-filter for single-phase grid-connected Photovoltaic (PV) inverter system is presented in this paper. A comparison between the designed LCL-filter and L-filter based single-phase grid-connected PV inverter system is carried out. The comparison results are given to validate the theoretical analysis and effectiveness of filters.