Parallel inverters based on switched inductor Z-Source impedance network

Considering the fast growing energy demand and existing problems of conventional fossil fuel, renewable energy has received more attention nowadays. In order to connect different kinds of renewable energy sources to common bus, power electronics converters are employed as the interface. As the system capacity increased, the former single power electronic converters (e.g. inverter) cannot fulfill the demand any more. It can be solved by high power rating devices. but the cost will be obviously high. parallel inverter may be the best choice for this issue. Instead of using single inverter, two or more inverters are connected in parallel and share output current. In this paper, the modeling, designing and stability analysis of parallel switched inductor Z-source inverters are derived for application in renewable energy system. Compared with the classical Z-source inverter (ZSI) the proposed inverter significantly increases the voltage boost inversion ability and also can increase the power capacity and the reliability of inverter systems. The proposed topology and its performances are validated using simulation results which are obtained in Matlab/Simulink.

Keywords:

Voltage gain , parallel operation , Z-source inverter (ZSI) , Switched Inductor Z-source inverter (SL-ZSI) , Modulation index