A Simplified Quadrangle Control Strategy for Four-Switch Buck-Boost Converter

The four-switch Buck-Boost (FSBB) converter is one of the most popular candidates in various applications. With the quadrangle control strategy, zero-voltage-switching (ZVS) of all power switches can be realized to achieve high frequency and high efficiency. Different control strategy optimization methods can help improve the whole range efficiency when the control complexity increases and typically requires a 3-D or 2-D look-up table. Based on the simplified analysis and calculation, the simplified linear control strategy with constant frequency is proposed. The control process is simple that can be calculated in real time. Meanwhile ZVS of all switches ensures the efficiency. With the same output current, the proposed control strategy has the mediate RMS current. It is convenient for engineering applications with practical values. The simulation results verify the feasibility of the simplified control strategy. The experimental demonstration will be conducted in the future.