Analysis and design of a wide input range DC-DC converter for high-speed generator energy storage systems

This paper presents a wide input range DC-DC converter with a robust control scheme for high speed generator energy storage systems. As the DC voltage converted from low-voltage high-speed generator may be lower or higher than the battery voltage, a step-up/down converter is needed for energy storage systems. The two-switch Buck-Boost (TSBB) converter is suitable for wide input voltage applications. In this paper the low-frequency small-signal models of TSBB converter under synchronous switching control method are built by averaged switch model. The main transfer function of control system is derived, the influences of the input parameters, load changes and the right half plane (RHP) zero on the control system are analyzed as well. Based on the small-signal models, the control strategy suited for wide input voltage is proposed. The feasibility of control strategy is verified by the simulation using SABER software. A 10 times input voltage range prototype is built and the correctness and effectiveness of the proposed control strategy are verified.