Design and Control of a High-Frequency, High-Efficiency Single-Stage Isolated DC/AC Inverter for UPS Systems

An uninterruptible power supply (UPS) application requires a DC/AC converter to connect AC loads to the battery DC power source. Most inverters used for such application are multi-stage including a bulky component in the DC link leading to decreased efficiency. Single stage inverters offer the advantages of increased power density, higher efficiency, compact size and reduced weight. This paper presents the design and control of a high-frequency, high-efficiency single-stage isolated DC/AC inverter for UPS applications. The discussed inverter employs a structure and a topology inspired from Dual Active bridge (DAB). The proposed topology allows bidirectional power flow. First, the modeling and the control of the proposed structure is developed. Then, the effectiveness of the proposed inverter and the control algorithms are validated through simulations.