Performance Evaluation of a 500 W Bidirectional Converter for DC Microgrid

In this paper, performance evaluation of linear and nonlinear control strategies for a non-isolated bidirectional half-bridge converter (HBC) operating in a DC (direct current) microgrid environment is presented. The presence of right-half plane zero in boost mode operation of HBC reduces its stability and limits the usefulness of a linear controller. The design procedure of a fuzzy logic controller (FLC) is discussed, and an FLC is designed for a 500 W HBC operating at 150 kHz. FLC dynamic and steady-state performance is evaluated against dual-loop proportional-integral controller in terms of rise time, overshoot, undershoot, settling time, and steady-state error. It is observed that FLC control provides better transient response and lesser steady-state error in both buck and boost modes of operation.