Modified Three-Phase Isolated Swiss-Type Rectifier with Lower Number of Switching Devices

Three-phase isolated Swiss-type rectifier (3P-ISR) can achieve the high-performance AC-DC conversion with low switching frequency, but also feature a relatively large number of switching devices. A modified 3P-ISR with simplified structure to reduce the number of switching devices is proposed in this paper. The novel 3P-ISR changes the clamping bidirectional switches to the dispersed structures, therefore, reducing the number of clamping switches by half. As a result, the total number of switching devices is reduced from 14 to 12, which would result in a significant decrease in hardware costs. Moreover, operation modes and modulation scheme of the proposed 3P-ISR are also analyzed and designed. Theoretical analysis and calculation results show that the system performance of the proposed structure is not affected, and can achieve a constant DC output voltage along with balanced sinusoidal input current. Finally, the simulation model of the proposed 3P-ISR has been built with MATLAB/Simulink software platform. The simulation results validate the correctness and effectiveness of the proposed 3P-ISR, which can effectively reduce the number of switching devices to achieve high-power-density AC-DC conversion.