Load adaptive current peak limited power tube connection method

Abstract

The invention discloses a load adaptive current peak limited power tube connection method. In a power tube driving circuit of a high-frequency direct current converter, a controllable current source is constructed, and the controllable current source is in series connection with the connection loop of the driving circuit. By utilization of the constructed controllable current source, a junction capacity of a power tube Q is charged to disconnect a power tube. The output current of the controllable current source, namely the connection current of the power tube is controlled by the load current value of the converter, and therefore the connection speed of the power tube can be subjected to real time tracking adjustment along with change of the load current. The driving connection current value of the power tube is increased along with decrease of the load to raise a connection speed of the power tube under a condition being less than a rated load, the connection loss of the power tube under a condition being less than the rated load is lowered, and the working efficiency of the converter is raised. During the connection speed real-time adjustment process, the current peak flowing past the power tube is limited to a peak value flowing under a rated load condition and safe and reliable work of the power tube is ensured.

Description

technical field [0001] The invention belongs to the field of power tube drive circuits of high-frequency direct-current converters, in particular to the field of real-time control of the turn-on speed of the power tube. Background technique [0002] In the high-frequency DC converter, the drive circuit is the bridge between the control circuit and the main circuit. The drive circuit of the power tube affects its switching speed, voltage and current peaks, and also affects the EMI of the converter and the working efficiency of the converter. . However, the turn-on speed is inconsistent with the turn-on loss and the turn-on current peak. The faster the turn-on speed of the power tube is, the smaller the turn-on loss and the larger the current peak are; the slower the turn-on speed is, the greater the turn-on loss is, but the turn-on The current peak will be relatively small, therefore, the reasonable design of the driving circuit is particularly important. [0003] attached ...

AI Technical Summary

Problems solved by technology

[0003] attached figure 1 It is a traditional voltage source driving method. When the power transistor Q is turned on, due to the reverse recovery current of the freewheeling diode D and the junction capacitance C ds The discharge current, which will generate a current spike on the power switch tube, and the faster the turn-on speed, the larger the current spike

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