Current source type three-phase PWM rectifier circuit

The output of the current source type three-phase PWM rectifier has DC current source characteristics, and uses the sinusoidal modulation method to control the distribution of the DC current I i in each switching device.

Make the AC current waveform close to a sine wave and in the same phase as the power supply voltage. The function of the AC side capacitor is to filter out high-order harmonics related to the switching frequency.

The advantages of current source rectifiers are:

① Due to the existence of the output inductor, it does not have the problems of bridge arm direct current flow and output short circuit;

② The switching device directly pulse-width modulates the DC current, so its input current control is simple and the control speed is fast.

weakness is:

① The rectifier output inductor has large volume, weight and loss;

② Commonly used full-control devices are bidirectionally conductive, and the main circuit configuration is inconvenient and the conduction loss is large.