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Power Balance Control Schemes For Cascaded Multilevel Inverters

Posted on:2006-12-13Degree:MasterType:Thesis
Country:ChinaCandidate:Y F SunFull Text:PDF
GTID:2132360152989649Subject:Power electronics and electric drive
Abstract/Summary:PDF Full Text Request
The cascade multilevel (ML) inverter can reduce the voltage stress of the power switches and output filter inductance, also it is easy to modularize and some phase voltages are redundant, so it is very suitable for high voltage applications. Due to the demands of separate dc sources, the cascade ML inverter is very suited for alternative energies such as photovoltaic panels and fuel cells. In order to balance the charge/discharge of the batteries in each H-bridge cell, the output power balance for each H-bridge cell is a very importance issue for the cascade ML inverter. In this paper, the output power of each H-bridge cell with some kinds of waveforms is derived, based on which, this paper proposes several improved power balance control schemes for the cascaded ML inverter, including staircase strategies, selective harmonic elimination strategies and carrier disposition SPWM strategies. The degree of output power balance for carrier phase-shifted SPWM strategies is analyzed in detail. The proposed schemes ensure the output power balance in one cycle, meanwhile the THD of the output voltage is very small. They also have fast response, and are easy to be implemented. The effectiveness of the proposed improved control schemes are verified by the simulation results.
Keywords/Search Tags:Cascaded inverter, Multilevel, Power balance control
PDF Full Text Request
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