Switched-boost inverter based on Inverse Watkins-Johnson topology

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 (EMI) noise immunity, which is achieved by allowing shoot-through of the inverter leg switches. This paper proposes an inverter circuit based on Inverse Watkins-Johnson topology that can achieve similar advantages as that of a ZSI. The proposed circuit requires two switches and one pair of LC filter apart from the VSI. The systematic development of this inverter topology is described starting from the basic Inverse Watkins-Johnson circuit. Steady-state analysis and implementation of the proposed topology are also described. The PWM control strategy of the inverter is explained. An experimental prototype is used to valid the proposed circuit.