Three-phase multilevel-voltage source converters with low switching frequencies and less distorted input voltages

A novel three-phase power converter which is suitable for high-voltage, high-power applications is proposed. This converter consists of a neutral-point-clamped (NPC) converter with a switching frequency at the power line frequency as the main power circuit, and an additional single-phase converter with a switching frequency at triple the power line frequency. This paper describes the operating principle, analysis, and synthesis of the input voltage waveforms in a single- and a double-converter system, as well as experimental results.<
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