Implementation issues of a fuzzy-logic-based three-phase active rectifier employing only Voltage sensors

Switch-mode rectifiers are becoming more and more interesting in those applications where bidirectional power flow, powerfactor correction, and electromagnetic interference reduction are required. Typical active rectifiers include current or voltage sensors, however, in order to obtain low-cost systems, their number should be reduced. In this paper, a current-sensorless active rectifier with feedforward fuzzy logic control is presented and discussed. The mathematical description of the system and the design of the fuzzy logic controller are introduced and analyzed; moreover the implementation on a SH7047 microcontroller is presented with emphasis on the most significant implementation issues. Experimental results are reported and discussed.