Inverse Watkins–Johnson Topology-Based Inverter

A Z-source inverter (ZSI) uses an L-C impedance network between the source and the voltage source inverter (VSI). It has the property of stepping down or stepping up the input voltage, as a result, the output can be either higher or lower than the input voltage as per requirement. This topology also possesses robust electromagnetic interference noise immunity, which is achieved by allowing shoot through of the inverter leg switches. This letter proposes an inverter circuit based on the inverse Watkins-Johnson (IWJ) topology that can achieve similar advantages as that of a ZSI. The proposed circuit requires two switches and one pair of an LC filter apart from the VSI. The systematic development of this inverter topology is described starting from the basic IWJ circuit. Steady-state analysis and implementation of the proposed topology are also described. The pulse width modulation control strategy of the inverter is explained. An experimental prototype is used to validate the proposed circuit.