Voltage-type single-phase half-bridge rectifier circuit and current-type single-phase full-bridge circuit

Voltage type single-phase half-bridge rectifier circuit

1. Structure of the main circuit

1. Voltage doubler circuit: If we assume that T1/T2 is always in the off state, then during the positive half cycle of the input voltage, D1/on, the DC voltage uc1 on the capacitor Cd1 is approximately equal to the peak value uNm of the input power supply ; similarly, the DC voltage uc2 on the capacitor Cd2 is approximately equal to the peak value uNm of the input power supply , so the DC output voltage uo= uc1+ uc2=2 uNm

When T1/T2 is turned on at a certain duty cycle, the circuit becomes a Boost converter, so uo= uc1+ uc2＞2 uNm

2. Control the duration of the pole pulse:

The circuit adopts SPWM control mode. The phases of the gates ug1 and ug2 of the two IGBTs in the upper and lower bridge arms in the main circuit are complementary. The repetition frequency fc and duty cycle D depend on the intersection of the carrier uc and the sinusoidal modulation signal ug.

Current-mode single-phase full-bridge circuit

The circuit is a current-type rectifier circuit, which is very similar to the single-quadrant buck circuit (BUCK circuit) in topology. In order to adapt to the nature of the AC power supply, Ts in the figure is a bidirectional controllable switch , and a single-phase bridge circuit composed of D1-D4 is used to replace the parallel freewheeling diode.