Comparison of Inverter Topologies for High-Speed Motor Drive Applications

This article investigates and compares the performance of three-phase inverters against sets of single-phase full-bridge inverters in motor drive applications. Comparisons are made for a common semiconductor device area and rms phase current ripple, and the regions of the design space in which each topology is advantageous are identified. It is found that separate full-bridge inverters are preferable for designs in which switching losses are dominant, whereas three-phase inverters are preferable for designs in which conduction losses are dominant. This result suggests that individual phase drive is desirable in applications requiring high switching frequencies, as in high-speed, low-inductance machines. A 10-kW system is constructed to enable experimental comparisons. The experimental results conducted at 3.6-kW validate analytical and simulation findings.