Comparison of Z-source inverter and traditional two-stage boost-buck inverter in grid-tied renewable energy generation

Z-source inverter and traditional two-stage buck-boost inverter are compared with respect to the voltage stress and maximum current stress of semiconductor devices and the inverter efficiency in grid-tied renewable energy generation application. The operation principles of the two inverters are introduced firstly, considering the two different PWM strategies used in Z-source inverter. Based on the principles, voltage stress and maximum current stress of semiconductor devices in both topologies are derived and compared. Then the efficiency of two inverters are evaluated and compared. The analysis and comparison results show that the traditional two-stage buck-boost inverter bares smaller voltage and current stress of semiconductor device and has higher efficiency than Z-source inverter under the same input and output conditions.