A switching strategy of chb inverter for pv system under nonuniform illuminating conditions

Abstract

This paper proposes a switching strategy for Cascaded H-bridge (CHB) multilevel inverter for photo voltaic (PV) power generation systems under nonuniform illuminating conditions. In order to minimize the switching frequency, selective harmonic elimination (SHE) technique is used to determine the inverter switching pattern. As the DC voltages are unbalanced and vary from time to time, the switching pattern has to change dynamically. How to implement the dynamic switching pattern by using a field programmable gate array (FPGA) is described in this paper. Several simulated and experimental results are included in this paper to show the effectiveness of the proposed method.