Boosted circuit of direct-hanging high-voltage power supply and soft start method

Abstract

The invention discloses a boosted circuit of a direct-hanging high-voltage power supply and a soft start method. The boosted circuit comprises an inductor L1, a switch S1, a diode D1 and a diode D2. One end of the inductor L1 is connected with a capacitor C1, the switch K1 and the anode of the diode D3; the other end of the switch K1 is connected with a low-voltage power supply; the other end of the inductor L1 is connected with the switch S1 and the anode of the diode D1; the cathode of the diode D1 is connected with a capacitor Cfly, a resistor RS3 and the anode of the diode D2. In an outputdirect-hanging high-voltage power supply application scene circuit, a novel three-level flying capacitor circuit is used and the unique soft start circuit is cooperated and all the switching voltagelevel of the system can be reduced by half. The low-voltage semiconductor switching characteristic is good and the selectivity is high so that the high frequency of the whole circuit can be realized,the inductance volume can be reduced, the volume of the whole mechanism can be reduced, and the cost of the whole system can be reduced.

Description

technical field [0001] The invention relates to the technical field of power supplies, in particular to a step-up circuit and a soft-start method for a direct-connected high-voltage power supply. Background technique [0002] In view of the increasingly serious environmental pollution, the country has begun to vigorously develop new energy vehicles, especially hydrogen fuel cell vehicles. Because the front end of the fuel cell receives hydrogen and oxygen, after the electrochemical reaction, in addition to generating electricity, the discharge is water. Without any pollution, it is regarded as an ideal clean energy. [0003] Although the fuel cell has many advantages, as a vehicle energy source, its output voltage and current characteristics are soft, its rated operating voltage is low, and it is unstable under interference. figure 1 It is shown that a DC / DC converter needs to be added between the fuel cell and the motor controller to convert and stabilize the voltage, so t...

AI Technical Summary

Problems solved by technology

[0006] image 3 In the circuit, when the switch KS2 is closed, the high-voltage battery charges C2 and C3 until the BUS voltage reaches the soft-start voltage amplitude, then KS2 is opened and K2 is closed. At this time, the BUS voltage is equal to the high-voltage battery voltage, and at this time due to The low-voltage power supply side of the input does not work, the voltage on the input side is 0, and the initial voltage of the flying capacitor is 0, so the BUS voltage will all be added to the diode D2, causing the diode to be damaged by overvoltage, or D2 must use a high-voltage switch tube can

Images