High-efficiency bidirectional single-input multiple-output power converter

This study investigates the design of a high-efficiency bidirectional single-input multiple-output (BSIMO) power converter. According to the power management, the proposed BSIMO converter can operate at a step-up state (energy release) and a step-down state (energy storage). At the step-up state, it can boost the voltage of a low-voltage input power source to a controllable high-voltage dc bus and middle-voltage output terminals. If there is redundant energy in the high-voltage dc bus, one can reversely transmit the energy. The high-voltage dc bus can take as the main power, and middle-voltage output terminals can supply powers for individual middle-voltage dc loads or to charge auxiliary power sources (e.g. battery modules). In this study, a coupled-inductor-based BSIMO converter utilises only three power switches to accomplish the bidirectional power control with the properties of voltage clamping and soft switching, and the corresponding device specifications are adequately designed. As a result, the objectives of high-efficiency power conversion, bidirectional energy transmission, high step-up/step-down ratios and various output voltages with different levels can be obtained. The effectiveness of the proposed BSIMO power converter is verified by experimental results of a kW-level prototype in practical applications.