Implementation of Grid-Connected Cascaded Multi-Level Inverter Based on FPGA for Centralized Photovoltaic Generation

This paper proposes a grid-connected cascaded multi-level inverter used in centralized photovoltaic generation. Field programmable gate array (FPGA) is applied to implement the multichannel Carrier Phase Shifting Sinusoidal Pulse Width Modulation(CPS-SPWM) strategy for the inverter. Analysis and practical implementation of the regular sampled three-phase CPS-SPWM waveform has been presented in this paper. An ALRERA FPGA chip is employed to fulfill all the function of modules, such as divider module, triangular carrier generation module, sine wave generation module, comparing module, dead time module and so on. The simulation and experimental results show that the presentation of this grid-connected cascaded multi-level inverter used in the photovoltaic generation system is feasible.