High performance soft switch for electric automobile DC/DC converter

Abstract

The invention provides a high performance soft switch for electric automobile DC / DC converter, belonging to the technical field of automobile soft switch, which solves the problem in the prior art in which the switch consumption in DC / DC is big and the wide-scope soft switch cannot be realized. The switch includes a control module, a driving module, a switch network, a deformation module and a filter rectifying module which are in turn connected, wherein a feedback module is connected between the output end of the filter rectifying module and the control module; the feedback module is used for sampling the voltage on the output end load and attenuating the voltage to output to the control module; the control module compares and amplifies the voltage according to the collected signal of the feedback module and respectively outputs four paths of trigger pulse control driving modules with different phase positions to drive the on-off of the switch tube; four switch tubes are indirectly switched on and off under the control of the trigger pulse; an over-lapping angle is generated in different switching on and off processes. The invention reduces the consumption of the switch in the DC / DC via a zero-voltage and zero-current double closed loop constant pressure control mode and realizes the soft switch in a wide scope.

Description

technical field [0001] The invention belongs to the technical field of automobile soft switches, and relates to a high-performance soft switch used for DC / DC converters of electric vehicles. Background technique [0002] In electric vehicles, the DC / DC converter is an essential component. It is a voltage converter that effectively outputs the required voltage after changing the input voltage. It has the function of ensuring the normal power supply of the vehicle-mounted low-voltage battery. The vehicle uses it to charge the electric energy in the power battery into the on-board low-voltage battery to ensure the normal operation of the vehicle's low-voltage electronic devices. Due to the frequent operation of the low-voltage battery on the vehicle, the DC / DC must also be turned on and off frequently, but affected by the conduction and turn-off losses of the switch tube, the DC / DC conversion part is often damaged. [0003] At present, most DC / DC products use hard switching or...

AI Technical Summary

Problems solved by technology

[0005] The Chinese patent literature discloses a pulse width modulation and zero-current zero-voltage resonant switch joint control inverter method with the patent number 94113331.1. The soft switching in this method utilizes the load in the full-bridge inverter circuit and the parasitic inductance and capacitance of the line during the switching process. The resonance of voltage and current is formed in the process, the switching device is turned off when the current crosses zero, and the switching device is turned on when the voltage is zero. This invention reduces the loss of the switching tube to a certain extent, but there are several shortcomings: 1. Zero-current and zero-voltage switching when switching off the switching device is relatively simple, and the control process of the super-forearm and super-rear arm leads to a narrow realization range of the soft switch; 2. Zero-current control is not easy to realize on the lagging arm

3. The full bridge switch circuit adjusts the dead time during the whole phase shift control process, so that the output of the converter is not reliable enough

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