Switched-capacitor-voltage-multiplier boost DC-AC inverter with adaptive stages

摘要

A multistage switched-capacitor-voltage-multiplier inverter (SCVMI) is proposed with a variable-conversion-ratio phase generator and a sinusoidal pulse-width-modulation controller for boost DC-AC conversion and high-efficiency regulation. Its power unit contains: SCVM booster and H-bridge. The SCVM booster includes two m_c.-stage switched-capacitor cells and two n_c-stage switched-capacitor cells in the interleaving operation to realize DC-DC boost gain of m_c × n_c at most. Here, the variable-conversion-ratio phase generator is suggested and adopted to change the running stage number and topological path for a suitable gain level of m × n (m = 1,2, ? ? ? ,m_c, n = 1,2, ? ? ? ,n_c.) to improve efficiency, especially for the lower AC output. The H-bridge is employed for DC-AC conversion, where four switches are controlled by sinusoidal pulse-width-modulation not only for full-wave output but also for output regulation as well as robustness to source/loading variation. Some theoretical analysis and design include: SCVMI model, steady-state/dynamic analysis, conversion ratio, power efficiency, stability, capacitance selection, output filter, and control design. Finally, the closed-loop SCVMI is simulated, and the hardware circuit is implemented and tested. All the results are illustrated to show the efficacy of this scheme.