High-frequency direct-current converter switch tube turn-off speed real-time adjustment method

Abstract

The invention provides a high-frequency direct-current converter switch tube turn-off speed real-time adjustment method. According to the method, a controllable resistor is constructed in a driving circuit of a high-frequency direct-current converter. The controllable resistor is connected into a turn-off current loop of a switch tube driving circuit in series so as to achieve switch tube turn-off speed real-time adjustment. The switch tube turn-off speed can be regulated in real time along with load current, the switch tube turn-off speed is improved under the condition of light load, and turn-off loss of a switch tube is reduced under the condition of the light load. The high-frequency direct-current converter switch tube turn-off speed real-time adjustment method is reliable and feasible, can be used for efficiency improvement of the direct-current converter, and particularly can be applied to the high-power direct-current converter with an IGBT as the switch tube so as to improve working efficiency of the high-power direct-current converter under the condition of the light load.

Description

[0001] technical field [0002] The invention relates to a method for real-time adjustment of the turn-off speed of a switching tube, which belongs to the field of switching tube driving circuits of high-frequency DC converters. Background technique [0003] In the high-frequency DC converter, the driving circuit of the switching tube is the main factor affecting its turn-on speed, turn-off speed and turn-off voltage stress, which also seriously affects the efficiency of the high-frequency DC converter. However, turn-off speed and turn-off voltage stress are contradictory. The faster the turn-off speed of the switch tube, the greater the turn-off voltage stress on the switch tube; and vice versa. as attached figure 1 As shown, when the switching tube Q 0 When it is turned off, if the current drops faster, the distributed inductance L in the circuit s The induced voltage L generated on s × d i / d t The bigger the L s × d i / d t with U s and act together on the...

AI Technical Summary

Problems solved by technology

However, in the traditional drive circuit design, after the circuit design is completed, the parameters are fixed, and the drive circuit parameters are not adjusted according to the circuit current. Of course, the turn-off speed of the driven switching tube cannot be adjusted.

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