Analysis of power losses in Z-source PV grid-connected inverter

Calculating power losses of the inverter plays an important role for improving system efficiency and power density, designing heat dissipation system and selecting the power devices. Generally, power losses include the main switch losses (conducting losses and switching losses), the drive losses, control circuit losses and losses of inductor. Among them, the losses of semiconductor power switching devices are the largest losses. This paper analyzed the power losses of blocking diode, switching devices of H-bridge, Z-source inductor and filter inductor in detail, combined operating principle with modulation strategy. And the practical formula is deduced. The experimental results verified the proposed method.