Simulation And Experiment Of Cascaded H-bridge High Voltage Inverter

Multilevel inverter topologies are increasingly being used in medium and high power applications due to their many advantages such as low power dissipation on power switches,low harmonic contents,low electromagnetic interference (EMI) outputs,etc.The thesis summarized the features of main circuit topology and control scheme for the high-voltage inverter,and taked cascaded h-bridge multilevel high-voltage inverter as the research object.The study includes the following aspects:Firstly,the thesis analyzed the phase-shifting method of phase-shifting transform-er secondary winding,and designed a 311A power unit according to the selection program of main circuit and power devices ,which meets the 6kV/2600kW or 10kV/4300kW high-voltage inverter running,and also calculated the heat data of power devices and sink thermal resistance.Furthermore,to improve the reliability of inverter operation and achieve the instantaneous power failure restart , the method which uses sensor to detect motor speed is proposed.Secondly, the thesis focued on the relationship between carrier phase-shift and output characteristic of cascaded multilevel inverter,and verfied the theoretical analysis by the simulation and experimental.In addition,a new selection program of filter capacitor was designed to replace the traditional one,and the failure modes and causes of filter capacitor were conducted.Lastly , the simulink model of cascaded h-bridge multiple-level high-voltage inverter is described.And then,the thesis introduced the running performance of the simulation model,and the experiment on 6kV/500kW high-voltage inverter. It is shown that the designed inverter achieves the expected goals.