| Summary: | 碩士 === 國立雲林科技大學 === 電機工程系碩士班 === 97 === A novel space vector modulation strategy for the multilevel inverter is proposed and it can operate in the linear modulation region and the overmodulation region. The multilevel space vector in the novel space vector modulation strategy will be equivalent to a few two-level space vectors. This strategy can simplify the complexity to determine the location of reference voltage easily and the nearest three vector approach will be used as the synthesis basis. The calculation amount of the vector’s dwelling time can also decrease and the optimized switching sequence can be achieved to reduce the switching losses.
When the modulation index of multilevel inverter gradually increases from the linear modulation region to the overmodulation region, the novel space vector modulation strategy can also be synthesized simply, it does not need an additional circuit by the proposed strategy and it can reduce the harmonic distortion by adequate modification in the specific angle scope. Furthermore, the multilevel inverter operating in the low modulation index can reduce the harmonic distortion by using the devices which are not utilized originally.
Finally, simulations and experimental results will be used to verify the proposed modulation strategy. The experimental circuit is the three-phase five-level inverter and the digital control of the system uses TI Company’s TMS320LF2407A digit signal processor.
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