PERFORMANCE INVESTIGATION OF Z SOURCE INVERTER USING SINE PULSE WIDTH MODULATION TECHNIQUE

Abstract

A relatively new inverter namely the Z source inverter has been introduced along with its equivalent circuit, operation principle. Traditional inverter has been compared with Z Source inverter. Advantage and disadvantage has been discussed. Although currently they are not in used but their areas of application has been discussed for the quickly understanding of the Z Source inverter.Z Source inverter and its control stratergy has been analysed in detail. Whenever necessary ,simulation has been performed . Than the design of the closed loop controller for the impedance network is done for the z source inverter. If there is any disturbance occur in the input source than the close loop controller make the dc link voltage constant by adjusting the value of shoot through duty ratio. The Z-Source inverter converter power in a single stage and it has capability of buck and boost the voltage in a same system by varying the duty ratio and modulation index. Therefore this system is capable of making economical power conversion in the distributed generation application. When the input is subjected to any input disturbance than there effect should be minimized. This can be done by using the close loop control strategy If there is a step input change in the load side than this effect will be transfer to the ac load side due to energy resettling .So, the shoot through duty ratio should be adjusted to avoid the propagation of disturbance get transferred to ac side. Simulation result is obtained to for the validation of the proposed controller. Last section is dedicated to the development of the Z Source inverter hardware.