This paper proposes the use of performance
enhanced multi-stage Cascaded quasi Z-source Inverter (CqZSI) topology for adjustable speed drives in Photo Voltaic (PV) applications. For the same boost factor, a new PV powered three-stage CqZSI system has an advantage of lesser shoot-through duty ratio compared to the disadvantage of traditional ZSI with very less boost ratio, increased shoot-through ratio and high component stress at the power switches. A 25% reduction in shoot-through duty cycle is achieved by using the three-stage cascaded solution. The boost factor of the proposed system is 1.5 times higher than single-stage system for the same input voltage. Simulation of the three-stage CqZSI fed induction motor drive is done and verified by experimental results.
The performance of the cascaded three-stage qZSI system is compared based on efficiency boost factor and shoot through performance. This paper illustrates that the performance enhanced CqZSI topology is a good alternative topology for efficient and highly reliable PV power generation system.