A computationally efficient robust voltage control for a single phase dual active bridge

Abstract

This paper proposes fractional and integer order sliding mode controllers (SMC) for the high voltage (HV) bridge control in a bidirectional dual active (DAB) converter. The proposed controllers are derived based on nonlinear model of DAB converter and the closed loop stability is ensured using integer and fractional order Lyapunov theorems. Fractional order controllers offer more degree of freedom to adjust the desired response of the system, however the implementation issues of such controllers are rarely explored. Both variants of control schemes are implemented on a DSP control card, and hardware-in-the-loop (HIL) and processor-in-the-loop (PIL) experiments are conducted using rapid control prototyping technique. In order to choose the most suitable robust controller, experimental data for the two performance indices namely robustness and computational resources utilization is compared for both integer and fractional order control schemes. The experimental results demonstrate that the integer order SMC utilizes reduced computational resources as compared to the fractional order SMC. Moreover it is further verified that integer order SMC exhibits comparable robustness as fractional order SMC under all test conditions.