Abstract:

With its advantages of high power density and high reliability, Vienna rectifier is widely used in communication power supply and electric vehicle charging and other high-voltage high-power situations. In order to realize the power factor correction (PFC) circuit characteristics of Vienna rectifier, the AC side current should be controlled as a sine wave with the same frequency and phase as the grid voltage to reduce the zero crossing distortion of the current. To further improve the power density of Vienna rectifier, switching losses should be reduced as much as possible. From the perspective of space vector,the space vector modulation strategy applicable to Vienna is analyzed. According to different control targets, discontinuous pulse width modulation (DPWM) is proposed to reduce the maximum switching loss and the zero crossing distortion of the current. Finally, the two proposed DPWM strategies are compared with SVPWM strategy through simulation. The feasibility and superiority of the two proposed DPWM strategies are verified.

Key words: Vienna rectifier, zero-crossing distortion of current converter, discontinuous pulse width modulation (DPWM), switching loss