MV Grid Integrated Multiport Configuration for EV Fast Charging Station

Sustainable solutions, including distributed generation from renewables, energy storage systems, and electric vehicles (EV), necessitate advanced power conversion and control techniques. The demand for hybrid dc-ac power systems is escalating due to technological advancements like fuel cells, solar PV panels, batteries, and ac-dc grids. Integrating highly nonlinear loads, such as EVs charging stations, with renewable energy sources further underscores this trend. Additionally, EV powertrains must smoothly manage the interaction between AC motors and DC sources, i.e., batteries, fuel cells, or super-capacitors, that is typically achieved through multiple power converters. In this case, EV drivetrains require two or more power converters to effectively regulate power flow between AC motors and DC sources. This multi-stage power processing requirement can be alleviated by designing a bidirectional power converter with multiple AC and DC ports. Multiport power converter configurations (MPCC) utilizing Dual Active Bridge (DAB) based solid-state transformers (SST) facilitate grid-integrated renewable energy sources for electric vehicle charging station (EVCS). Asymmetrical loading conditions induce DC-link voltage imbalance, hence impacting the stability of the DAB converter. EVCSs deteriorate grid power quality due to the presence of harmonic component at point of common coupling (PCC). In this paper, a super-twisting algorithm (STA) with dual phase shift modulation has been presented for the DAB power converter. Such control scheme enhances the output voltage regulation and eradicates chattering. A disturbance observer is developed to compensate for nonlinearities and variations in circuit parameters. Additionally, a moving average filter-based phase-locked loop is employed for synchronizing the grid to monitor voltage in accordance with the estimated grid frequency.