Active three-phase rectifier with only one current sensor in the DC-link

Abstract

Three-phase active rectifiers with six transistors are expected to be used in many future power electronic applications especially because of their clean power load of the grid. This topology is expensive and cost-reduction is an important issue. This paper proposes a three-phase active rectifier topology, where the number of current sensors are reduced from three to one and still the same performance is kept in respect to control bandwidth and protection. Instead of using three current sensors to the grid, one current sensor is put into the DC-link. Difficulties in respect to using one current sensor are discussed and solved. The topology is implemented in the laboratory and test results show the same results when comparing the performance using one or three current sensors. It can be concluded the topology can be used in future three-phase active rectifiers.