DUAL VOLTAGE CONTROL OF REDUCED SWITCH HYBRID QUASI Z MULTILEVEL INVERTER FOR ISOLATED ENERGY SYSTEMS

Abstract

This paper investigates the performance of new reduced switch hybrid Quasi Z inverter with dual voltage control for isolated energy systems. The proposed hybrid inverter integrates the stepped DC link circuit and the Quasi Z source inverter to yield buck/boosted multilevel AC voltage. It features the advantages of reduced source and switch count, minimized stress and inrush current, use of single impedance network for buck/boost operation thus reducing the passive component requirement and mitigated harmonic profile. Efficient operation of the system is obtained by independent dual feedback control in a way to minimize the high frequency switching variations of the inverter switches. Improved efficiency by 5% is obtained by dual voltage control of proposed inverter thus enhancing system performance. Detailed theoretical analysis of the equivalent model for different operating modes is described and the simulation is performed for a seven level proposed inverter in MATLAB/Simulink. Experimentation of the prototype model of proposed inverter is done in laboratory and the results are validated.