A Three-Phase Voltage Doubler Topology Consisted of Small Number of Switching Devices with Low Switching Frequency

Three-phase voltage doublers are used to boost DC link voltages for many applications, such as motor drives and uninterruptible power supplies. However, conventional topologies are complex and need many switching devices, which increases their cost. The conventional topologies have a power factor correction (PFC) function as well as a boosting function. A low-cost configuration is required for industry, and applications which do not need PFC exist. Consequently, it has been difficult to implement them for industrial use. This paper proposes a simple circuit topology of a three-phase voltage doubler. The proposed topology focuses on only boosting the voltage and it reduces the number of switching devices to less than half that of other topologies by sharing a bi-directional switch with three phases. It was evaluated in experiments with a 4-kW prototype. The results show that the proposed topology can boost the DC link voltage to twice that of a normal diode bridge rectifier over the whole load range.