Dead-time effect and compensations of three-level neutral pointclamp inverters for high-performance drive applications

摘要

Due to the use of high-power devices and slow-switching frequencynin a three-level neutral point clamp inverter, the dead-time effect maynnot be compensated sufficiently fast by using methods developed for thentwo-level inverter. In this paper, the dead-time effect in a three-levelninverter with snubber circuits is analyzed to reveal that it does notnonly depend on load current direction, but also on magnitude. Thensnubber network also plays an important role in determining the outputnphase voltage during the dead-time period. Software techniques arenproposed to compensate the dead-time effect as soon as it occurs asndemanded by the slow-switching frequency. Experimental results showntheir effectiveness