A Novel VFVDC Optimized Full Bridge Inverter Control Strategy for Independent Solar Power Systems

Abstract

This research explored the independent solar power system (ISPS), including the maximum power point tracking (MPPT) technology and the DC (direct current) to AC (alternating current) full-bridge inverter (FBI) control technology. This study combined the perturb and observe (P&O) algorithm based on the output voltage control strategy and the proposed optimized FBI control strategy to the ISPS. The proposed variable frequency and variable duty cycle (VFVDC) optimized FBI control strategy had adjustable frequency and duty cycle. The proposed VFVDC control strategy was compared with the sinusoidal pulse width modulation (SPWM). When the output of FBI was at a low voltage level, the operating frequency was 10 kHz. Conversely, when the FBI gave a high voltage level output, the operating frequency was 1 kHz. This control improved the switching loss of 4 power MOSFETs in the FBI and thus improved the performance with a low harmonic amount. To further verify the explored system, this study used MATLAB to compare the proposed control strategy and SPWM control method. The simulation results verified that the proposed control strategy total harmonic distortion (THD) = 1.02% was better than the SPWM control method THD = 3.23%, then the low pass filter (LPF) volume was reduced. Finally, the actual ISPS was used for actual measurement and verification. The proposed control strategy had a low harmonic level, can operate stably and effectively, and thus be used for the actual fulfillment of electricity needs.