Method for solving magnetic bias

Abstract

The invention provides a method for solving magnetic bias. By adopting the method, low-speed adjustment can be conducted under the condition that magnetic bias is not serious, thereby guaranteeing that magnetic bias is prevented under most working conditions, and output external characteristics are not affected; and under the condition of severe magnetic bias, the capacitor voltage is rapidly discharged through a blocking capacitor voltage discharging circuit, further deterioration of the magnetic bias is inhibited, and high-reliability work of the system is guaranteed. The method is suitablefor all topologies with magnetic bias risks, completely solves the problem of magnetic bias generation through a software and hardware combination mode, and improves the reliability.

Description

technical field [0001] The invention relates to the field of high-frequency switching power supply and electric vehicle charging module, in particular to a method for solving bias magnetism. Background technique [0002] At present, there are many topologies in the power supply field, and many new architectures (including two-level, three-level and multi-level full-bridge topologies) are derived from the full-bridge topology as the basic structure. In the high-power field, the phase-shifted full bridge and dual active bridge (bidirectional topology) schemes are widely used. The common characteristics of these topologies are high frequency, isolation and transformer work in quadrants 1 and 3. Ideally, 1, The 3-quadrant drive is completely symmetrical, and there is no magnetic bias phenomenon in the transformer in a complete cycle. However, in the actual circuit, due to the difference in electronic components and the timing accuracy of the software control strategy, there will...

AI Technical Summary

Problems solved by technology

The above method has a good effect in solving the case of driving asymmetry and slowly changing cumulative bias. For some special working conditions, such as sudden full load or sudden unloading, the calculation result of the loop will cause the duty cycle to change rapidly. The duty cycle of each beat is different. Since the duty cycle changes rapidly, the magnetic bias may be very serious within a few or dozens of switching cycles. The transformer is saturated and the current rises rapidly, and the circuit has a large Therefore, in this case, a method to quickly solve the bias magnetic field is proposed, that is, by connecting the switching tube in parallel with the DC blocking capacitor, by quickly releasing the energy of the DC blocking capacitor, the capacitor voltage drops rapidly, and at the same time matching and adjusting the drive of the switching tube Timing strategy to effectively solve the magnetic bias problem

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