Design and Control of Grid-tied Power Electronics Converter for Battery Energy Storage System

Abstract

Abstract Battery Energy Storage Systems (BESS) play a key role in supporting renewable energy integration and enabling grid services such as load balancing and backup power. This thesis compares two grid-tied power conversion systems for BESS applications: one using a traditional line-frequency transformer (LFT) for isolation, and another using a high-frequency transformer (HFT) integrated into Dual Active Bridge (DAB) converter. Both systems are modeled and simulated in MTALAB and PLECS to evaluate their efficiency and suitability for high-power applications. The LFT system offers simplicity but suffers low efficiency at light load due to constant core losses. In contrast, the HFT-based system, using multiple parallel DAB converters, maintains consistently high efficiency across a wide power range and supports a more compact, scalable design. The results highlight the trade-offs between LFT and HFT approaches in terms of power density, efficiency, and flexibility, providing guidance for future BESS designs in grid-connected environments.