A Vienna rectifier has been widely applied when power density is a design objective and usually works with a high switching frequency. Therefore, it is necessary to decrease the switching loss to reduce the temperature of the device. Discontinuous pulse width modulation (DPWM) is able to reduce the switching loss of power of the device. However, the five-stage vector synthesis method of DPWM will increase the current harmonics. To reduce the current harmonic distortions caused by the DPWM method and reduce the switching loss of a Vienna rectifier, a modified DPWM modulation method with minimum switching loss for a Vienna rectifier is proposed in this paper, and the reduction of current harmonic is achieved by injecting the optimal zero-sequence component into three-phase modulation waves in the subsectors at the large-sector transitional area. Furthermore, the three-level topology has a problem of unbalanced neutral point potential. By changing the clamp mode in each subsector leading to different currents, leading to the neutral point, the neutral point potential is balanced. Finally, all these proposed modulation and control strategies are verified by simulation and experiment results. (c) 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
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