PFC lossless absorption main circuit

The charging process in the normal charging mode is generally performed at home and in public places. The charging power level in the normal charging mode is usually 6.6kW, and the typical charging time is 5 to 8 hours. The charging power converters in normal charging mode and emergency charging mode are similar, and a single-stage AC/DC converter can also be used in normal charging mode. However, due to the single-stage converter with PFC function, the peak current of the switching tube is very large. In the two-stage converter, the PFC stage can use a traditional Boost circuit, and the switching tube can use either soft switching or hard switching. But in order to improve efficiency, a soft-switching Boost converter should be selected. The traditional AC/DC full-wave rectifier circuit uses a rectifier + capacitor filter circuit. This circuit is a combination of nonlinear devices and energy storage components. The waveform of the input AC voltage is sinusoidal, but the waveform of the input current is severely distorted and appears in a pulse shape. The resulting harmonic current has a harmful effect on the power grid and reduces the input power factor of the power supply. In this design, the rectifier circuit part uses an active power factor correction circuit (APFC) to avoid the above shortcomings. The circuit is shown in the figure.