Hybrid Control of BCM Soft-switching Three Phase Micro-inverter

A new hybrid control of soft switching boundary conduction mode (BCM) inverter that features an easy digital implementation and reduced number of analog components is presented in this paper. A traditional half-bridge three-phase inverter topology can realize soft switching through implementing BCM operation, thus no additional power devices or magnetic components are required. The proposed hybrid method facilitates the control of BCM inverter by taking full advantage of the DSP resources. The simulation was carried out to verify the proposed control technique. A brief analysis of current modulation of soft switching BCM inverter is given in the paper. A 400W 120Vac three-phase prototype was built. The experimental results show that the soft switching can be realized under different load conditions and the peak efficiency can reach up to 96.5%.