Control circuit of power module in power electronic transformer

Abstract

The invention provides a control circuit of a power module in a power electronic transformer, comprising: a positive half cycle detection module, the input end of the positive half cycle detection module is connected to the transformer secondary side signal output end, when it is detected that the current signal is in the positive half cycle , output high level through the output terminal; negative half cycle detection module, the input terminal of the negative half cycle detection module is connected to the output terminal of the transformer secondary signal, when it is detected that the current signal is in the negative half cycle, the output terminal outputs a high level ; The first AND gate, one input end of the first AND gate is connected to the output end of the positive half-cycle detection module, the other input end is connected to the driving signal, and the output end of the first AND gate is connected to a group of the secondary side rectifier bridge The control pole of the switch tube; the second AND gate, one input end of the second AND gate is connected to the output end of the negative half-cycle detection module, the other input end is connected to the inversion signal of the driving signal, and the output end of the second AND gate Connect to the control pole of another group of switches in the secondary side rectifier bridge.

Description

technical field [0001] The invention relates to the technical field of power electronic transformers, in particular to a control circuit of a power module in a power electronic transformer. Background technique [0002] The power unit of the power electronic transformer generally adopts a bridge topology circuit. When working in the forward direction, the MOS tube switch in the primary side bridge circuit operates. If the MOS tube in the secondary side bridge circuit is not turned on, the body diode in the MOS tube starts. rectification. Also in reverse operation, the MOS transistor in the secondary-side bridge circuit switches. If the MOS transistor in the primary-side bridge circuit is not turned on, the body diode of the MOS transistor acts as a rectifier. When the MOS tube is used as a body diode, the voltage drop is relatively large, and the power consumption is relatively large. In order to reduce the loss, the MOS tube is turned on when the diode is rectified so tha...

AI Technical Summary

Problems solved by technology

However, due to the existence of the threshold, the current goes through the body diode first after crossing zero, and then flows through the MOS tube after a certain period of time. Although the efficiency is improved, it is not optimal, and if the threshold is not set properly, there will be high Frequency conduction, but will increase the loss

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