A buck soft switching circuit and control method for supercapacitor charging

Abstract

The invention discloses a Buck soft switching circuit for supercapacitor charging, comprising a Buck circuit composed of an input voltage source Vh, an output voltage source Vl, a main inductance Lm, a main switching tube S2, and a main diode D1, and the output voltage source Vl A first capacitor C1 is connected between the negative electrode and the collector of the main switching tube S2, a main diode D1 is connected in parallel between the two ends of the main inductance Lm and the output voltage source V1, the collector of the main switching tube S2 and the first auxiliary switching tube Sa2 Collector connection, resonant capacitor Cr is connected between the emitter of the main switching tube S2 and the emitter of the first auxiliary switching tube Sa2, and the emitter of the first auxiliary switching tube Sa2 is also connected with the collector of the second auxiliary switching tube Sa3 , the emitter of the second auxiliary switching transistor Sa3 is connected to the resonant inductor Lr and the first auxiliary diode Da1, and the resonant inductor Lr and the first auxiliary diode Da1 are connected in series and then connected in parallel with the main diode D1. The invention also discloses a control method for the Buck soft switch circuit for accumulator charging. The soft switching circuit of the present invention reduces switching loss.

Description

technical field [0001] The invention belongs to the technical field of electric vehicle systems and uninterruptible power supply systems, and in particular relates to a Buck soft switch circuit for supercapacitor charging, and also relates to a control method for the above circuit. Background technique [0002] In recent years, due to the deteriorating energy and environmental problems, people's demand for electric vehicles has become more and more urgent. In electric vehicles, although the battery is a key part, the life of the battery is severely shortened due to the increase in the number of charges and discharges, and the power characteristics of the battery cannot meet the power requirements of the car under special conditions such as starting and accelerating. As an auxiliary power supply, supercapacitors can make up for this shortcoming. Therefore, the charging and discharging technology of supercapacitors has received enough attention in many countries, and extensive...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a Buck soft switching circuit for supercapacitor charging, which solves the problems of the existing supercapacitor charging auxiliary switch tube hard opening and hard turning off, large switching loss and short system working life

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