Sliding Mode Controller with Disturbance Rejection for Bidirectional Transformerless AC/DC Converter in EV Onboard Charger

Transformerless power converters are trending in automotive sector as the demand for onboard chargers rises. The high efficiency and leakage current mitigating property of highly efficient and reliable inverter concept (HERIC) converter make it an excellent choice among transformerless topologies. By using appropriate modulation technique, the HERIC converter can transmit bidirectional power. This article presents design of sliding mode controller (SMC) for bidirectional HERIC converter to enhance the tracking performance. The SMC parameters are selected utilizing Harris hawks optimization (HHO) algorithm. During vehicle-to-grid (V2G) operation, sliding mode controller is developed for reactive power regulation of the grid connected HERIC converter and for grid-to-vehicle (G2V) operation, the converter is operated with very low voltage ripples in the DC side. The stability analysis is done by considering model uncertainties to guarantee sinusoidal grid current, low THD, and unity power factor even in the presence of grid disturbances and parametric variations. The Typhoon Hardware in the Loop (HIL) 402 device is used to execute the real-time testing. The results confirmed the efficacy and robustness of the designed controller under different scenarios for both modes of operation.