Comparative study of dual active bridge isolated DC to DC converter with single phase shift and dual phase shift control techniques

Abstract

Increased demand of battery energy storage systems, has increased the need of bidirectional DC-DC converters with galvanic isolation. For high power density, compact size, less weight and low cost, Power Conversion Systems with High Frequency tie connection are most likely be preferable. Dual Active Bridge (DAB) Isolated Bidirectional DC-DC converter (IBDC) is the core circuit of High Frequency Power Conversion Systems. Most common topology of dual active bridge converter has two full bridge converters connected through a high frequency transformer. Bi-directional power flow capability, high power density, high efficiency, innate soft switching, low number of passive components and galvanic isolation are some attributes of DAB attracting industry. This paper discusses the application of Dual Active Bridge (DAB) Isolated Bi-directional DC-DC (IBDC) converter in Uninterrupted Power Supplies (UPS), also compares the Dual Phase Shift (DPS) control with the Single Phase Shift (SPS) control in parameters like voltage, current and VA stress, and inductor peak current. The MATLAB & SIMULINK simulation results for both charging and discharging mode are shown for closed loop control of the two control strategies viz., SPS and DPS control using PI controller by varying the load in two steps.