Multiparalleling of IGBT inverters for high output power

The use of IGBT inverters for variable speed drives has gained tremendous popularity in recent times, because of the many advantages offered by this technology. Excellent control performance, high reliability and high efficiency as well as low cost and easy maintenance are the most important benefits. The output power of IGBT inverters in the low voltage range, however, is limited to some hundred kW using the IGBTs available today. To increase the output power of IGBT inverters, the method of paralleling complete inverter units provides an advantageous solution. In this paper, a multiparallel system is presented, which allows up to eight IGBT inverters to be connected in parallel and which offers many very advantageous features. An extremely high output power of some MW can be achieved in the low voltage range.