Single-Stage Multi-Input Buck-Boost Inverter

A novel multi-input single-stage Flyback type inverter with series connection and supply time overlapping at the input is presented. Circuit topology, energy management control strategy (EMCS), analysis of high-frequency switching procedure, multiple duty cycle steady-state relationship, common mode voltage suppression, and active clamp control scheme are investigated in detail. The proposed inverter structure is comprised of series connection multi-input selected switches and a single-input single-output combined isolation bidirectional Flyback DC chopper. The master-slave SPWM integrated control method for energy management based on separate control of input sources with feedforward of input voltage and feedback of output voltage is proposed, which enables the management of energy sources by controlling output power ratio of multiple inputs and the instantaneous value of output voltage and finally realizes safe and stable switching between two modes of power supply. A 1kW multi-new-energy inverter prototype has been designed and built with excellent features such as one-stage energy conversion, great efficiency of conversion, small size, light weight, large adjustable duty ratio range, high quality of output waveform, seamless and stable switching between two power modes.