Design and Analysis of High-Gain Switched-Capacitor-Inductor-Based Inverter for Step-Up DC-AC Conversion

Abstract

This paper presents the analysis, design and implementation of a closed-loop high-gain switched-capacitor-inductor-based inverter (SCII) by combining a sinusoidal pulse-width-modulation (SPWM) controller and phase generator for realizing the step-up inversion and regulation. The power part is composed of two cascaded sub-circuits from source [Formula: see text] to output voltage [Formula: see text]: (i) SCI booster (one resonant inductor, 4 pumping capacitors and 7 switches regulated by phase generator) and (ii) DC-link inverter (one filter capacitor and 4 switches controlled by SPWM), in order to provide a wide step-up output range of [Formula: see text] as: [Formula: see text] for DC-AC conversion, where [Formula: see text] ([Formula: see text]) is the ratio cycle of charging the inductor (e.g., the maximum of [Formula: see text] reaches 13.8 times voltage of [Formula: see text] while [Formula: see text]). Here, by using the phase generator, the maximum of step-up gain can be regulated for fitting the need of AC load. Further, the SPWM controller is employed to enhance regulation capability for the different amplitude and frequency of output, as well as robustness to loading variation. Some theoretical analysis and design are included: formulation, steady-state analysis, conversion ratio, power efficiency, inductance and capacitance selection, circuit stability and control design. Finally, the performance of SCII is simulated, and verified experimentally on the implemented prototype circuit, and the results are illustrated to show the efficacy of this scheme.