Novel Three-Phase Buck-Boost Inverter With Reduced Input Current Ripple and No Short-Circuit and Open-Circuit Faults

This article proposes a new single-stage three-phase buck-boost inverter and control scheme, which remarkably reduces both the low and high-frequency ripple components in the input current. The low-frequency ripple component is eliminated by phase-shifting the output three-phase voltages by 120°. The high-frequency ripple component is decreased by doubling the effective switching frequencies and lowering the voltages of the input inductors. The proposed inverter has buck-boost dc-ac conversion ability and contains only six active switches. It is shortcircuiting free and can avoid the reverse recovery losses of the body diodes of the MOSFETs. The proposed inverter has better spectral performance and has a lower distortion in the output waveforms due to no delays (equivalent to dead-time in the traditional three-phase inverter) in the switching signals. To validate the performance and advantages of the proposed inverter, detailed analytical, simulation, and experimental results are reported. Experiments have been conducted with a 1.5-kW laboratory prototype at a 50 kHz switching frequency for the lineline output voltage of 110-220 Vrms/60. At the end, integration of inductors is also suggested to decrease the magnetic volume.