A new adaptive fuzzy logic control method for DC-to-DC converter
This paper introduces a new fuzzy logic controller (FLC) using inductor current feedback for significantly improving the dynamic performance of DC-to-DC converters. Inductor current plays a very important role in high performance DC-to-DC converter control and FLC is suitable to deal with time-varying nonlinear nature of power converters. Based on the feedback of the inductor current, the new control method combines the merits of both the conventional FLC and current mode control. Furthermore, extended state observer (ESO) has been developed to ensure high dynamic performance of DC-to-DC converters. By using ESO, the influence of load disturbances and parameter changes are accurately estimated and compensated. The simulation results show that the proposed FLC with ESO ensures very good robustness and adaptability under modeling uncertainty and external disturbance, such as load current variation, supply voltage changes and converter parameter changes. In addition, small signal frequency response analysis demonstrates that by using the proposed FLC, the bandwidth and phase margin of the closed loop system have been significantly increased.