Half-Controlled Boost Rectifier for Low-Power High-Speed Permanent-Magnet Generators

Literature reports several future portable and distributed power supplies in the watt-to-kilowatt range based on rotating machinery equipped with a variable-speed permanent-magnet generator. In order to generate a constant direct-current output voltage, an ultracompact highly efficient low-power rectifier is required. A suitable concept, i.e., the half-controlled three-phase pulsewidth-modulation boost rectifier (HCBR), is analyzed in this paper. In previous literature, there is only limited information available, particularly concerning current stresses, common-mode characteristics, and operating principles. Therefore, the HCBR topology analysis is completed in this paper. Furthermore, a novel modulation scheme improving the power electronics efficiency is proposed using space-vector analysis. The integration into a compressed-air-to-electric-power system with a generator rotating at 350 000 r/min is presented, and the measurements verify the theoretical results with an efficiency increase of 2% for the novel modulation scheme.