Selection of suitable Topology and Switching Technique of ZSI for wind power application

Acomparative study of three topologies of recentlydeveloped voltage-fed z-source inverter (ZSI) such assimple ZSI, quasi-ZSI and trans-QZSIis presented inthis paper. Different control techniques, proposedearlier for simple ZSI such as simple boost control,maximum boost control and constant boost control,have been applied here for all type of ZSI topologies.The detailed comparative evaluation of all topologiesunder differentcontroltechniques isdone inwindpower applications. For the common boost factor andmodulation index, theoutput voltage of all ZSIswithsamedcpowersupply and load are evaluated. Theoperating principles are analysed and the boostfactor, voltage gain, duty ratio and voltage stressacross the switches are derived.Therelationshipsamong them are comparedeven under variablecircuit parameters and switch frequency whichsuggests trans-QZSI with maximum constant boostcontrol switching technique as the most suitablecombinationfor the wind power application.