Behavior and Loss Modeling of a Three-Phase Resonant Pole Inverter Operating with 120° Double FlatTop Modulation

This paper describes the loss modeling and optimization of a grid-connected resonant pole inverter operating with 120deg double flattop modulation (Rigbers et al., 2005). The proposed architecture achieves soft-switching with highly reduced current stresses compared to the conventional resonant pole inverter (Divan and Skibinski, 1987) and (Divan et al., 1988) without additional components. This concept is based on the fact that a symmetrical three-phase system delivers or draws always constant power to/from the grid with 120deg phase shifted sinusoidal phase voltages of same amplitude and coherent sinusoidal phase currents. Simple analytic behavior and loss models for all active and passive components are derived and verified using a 5 kW prototype