A gain/efficiency‐enhanced bidirectional switched‐capacitor DC‐DC converter

A closed‐loop gain/efficiency‐enhanced bidirectional switched‐capacitor converter (BSCC) is proposed by combining an adaptive‐conversion‐ratio (ACR) phase generator and pulse‐width‐modulation (PWM) controller for bidirectional step‐up/down DC‐DC conversion and regulation. For realizing gain‐enhanced, the power part consists of one m_c‐stage cell and one n_c‐stage cell in cascade between low‐voltage (LV) and high‐voltage (HV) sides to boost HV voltage into m_c × n_c times voltage of LV source at most, or convert LV voltage into 1/(m_c × n_c) times voltage of HV source at most. For realizing efficiency‐enhanced, the ACR idea with adapting stage number m, n is built in the phase generator to obtain a suitable step‐up/down gain: m × n or 1/(m × n) (m = 1, 2, …, m_c, n = 1, 2, …, n_c). Further, the output regulation and robustness to source/loading variation can be enhanced by PWM on the LV/HV sides. Some theoretical analysis and control design are included as: modeling, steady‐state analysis, conversion ratio, efficiency, capacitance selection, and control design. Finally, the performance of this scheme is verified experimentally on a BSCC prototype, and all results are illustrated to show the efficacy of this scheme. Copyright © 2012 John Wiley & Sons, Ltd.