A Forward-Type Single-Stage Multi-Input Inverter With Series-Time-Overlapping Power Supply

A forward-type single-stage multi-input inverter with series-time-overlapping power supply is proposed. The circuit structure and topological family, energy management control strategy (EMCS), high-frequency (HF) switching process analysis, the relationship between multiple duty cycles and power decoupling, and common mode (CM) interference suppression between multiple inputs are fully studied. The circuit structure is composed of multi-input selection switches in series and an isolated bidirectional forward-type single-input single-output inverter. This topological family includes six circuits, such as full-bridge type. A master–slave energy management sinusoidal pulse width modulation (SPWM) compound control strategy with independent control of input source power based on input voltage feedforward and output voltage feedback is proposed. It realizes the energy management of the input source by controlling the instantaneous value of the output voltage and the output power ratio of the multiple inputs and achieves the smooth switching between the two power supply modes. The designed and developed 3-kVA inverter prototype has excellent performances, such as single-stage power conversion, HF electrical isolation, high conversion efficiency, small size and weight, wide duty cycle adjustment range, high output waveform quality, and strong load adaptability.