A Three-Phase Dual-Input Inverter Without Risk Of Shoot-Through

The two-stage DC-AC power conversion system has been applied widely in aeronautical static inverters,photovoltaic on-grid inverters,etc.But in the system,all the power is processed twice,which limites the improvement of the efficiency.A family of three-phase dual-input dual-buck inverters(TP-DIDBI)is presented in this paper.The low voltage DC source can directly supply the inverter in the topologies.As a result,the number of conversion stages can be reduced and the efficiency can be improved.Based on the existing dual-input positive pulsating voltage source cells(DIP-PVSCs),dual-input negative pulsating voltage source cells(DIN-PVSCs)and dual-input bi-directional pulsating voltage source cells(DIB-PVSCs)are derived.A family of three-phase dual-input dual-buck inverters is proposed on the basis of these cells.The merits of dual-buck inverters are remained,such as no shoot-through problem,freewheeling current through independent diodes instead of body diodes of switches.What's more,the topologies can output three voltage levels per phase.When they are applied in quasi-single-stage inverters,the number of conversion stages can be reduced and the efficiency can be improved.Taking a typical topology as the example,the operation modes are analyzed and the modulation strategy is given.For the chosen topology,its operation characteristics are analyzed in detail,such as harmonic characteristics of output voltage,power conducting characteristics.The calculation of powe loss proves that quasi-single-stage based on TP-DIDBI has higher efficiency than traditional two-stage inverter based on dual-buck phase.A 2 kW prototype of quasi-single-stage inverter based on TP-DIDBI is built.The feasibility of the proposed topology and its modulation strategy,the correctness of the theoretical calculation are validated by both simulation and experimental results.