A Self-adaptive Fuzzy Control Scheme of High Frequency Link SPWM Inverters

As the high frequency link (HFL) SPWM inverter possesses highly nonlinear property and variable parameters due to its special structure, the perfect control can not be obtained with conventional control methods especially under nonlinear load. A self-adaptive fuzzy control scheme in this paper is proposed for a single-phase high frequency isolated DCACAC inverter, in which a novel assistant fuzzy controller is designed to improve the self-adaptive and robust property by adjusting the scaling factor on-line. It takes a role to provide stronger control action for a large voltage error and a smoother control action for a small voltage error considering synchronously the error change. This in turn ensures that high quality output voltage is always maintained on HFL while the transient response improved regardless of the loading property. Simulation and experiment results of 1.5 kW prototype are shown in the paper. Comparison between self-adaptive fuzzy controller based on scaling factor self-adjusting and conventional FC verifies the proposed control method