Mutual inductor magnetic balance method and device of multi-state switch circuit

Abstract

The invention relates to a mutual inductor magnetic balance method of a multi-state switch circuit. The mutual inductor magnetic balance method comprises the steps of S1, sampling a difference mode current of a mutual inductor; S2, comparing the difference mode current with a reference signal; and S3, controlling duty cycle of a main switching tube of a bridge arm of the multi-state switch circuit according to a comparison result so as to acquire magnetic balance of the mutual inductor. By implementing the mutual inductor magnetic balance method and device of the multi-state switch circuit, the difference mode current of the mutual inductor is sampled, the duty cycle of the main switching tube of the bridge arm of the multi-state switch circuit is controlled, and thus, the magnetic balance of the mutual inductor can be further acquired.

Description

technical field [0001] The invention relates to a multi-state switch circuit, more specifically, to a method and device for magnetic balance of a transformer of a multi-state switch circuit. Background technique [0002] The multi-state switch structure usually includes a transformer and a set of bridge arms composed of diodes and switch tubes. Although the magnetic coupling characteristics of the transformer itself in the multi-state switch structure can realize the current sharing control of the common-mode current, due to the discreteness of the system device parameters, the deviation of the inductance, the voltage change, the driving delay, and the dead time, etc., A low-frequency voltage drop will develop across the transformers in the multi-state switching configuration. When the product of amplitude and seconds generated by the pressure difference exceeds the allowable value of the magnetic core, it will cause the transformer to saturate, resulting in that the maximu...

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Problems solved by technology

Although the magnetic coupling characteristics of the transformer itself in the multi-state switch structure can realize the current sharing control of the common-mode current, due to the discreteness of the system device parameters, the deviation of the inductance, the voltage change, the driving delay, and the dead time, etc., Will create a low frequency voltage drop across the transformer in a multi-state switching configuration

When the product of amplitude and seconds generated by the pressure difference exceeds the allowable value of the magnetic core, it will cause the transformer to saturate, resulting in that the maximum magnetic induction intensity B value of the actual transformer is much higher than the theoretically calculated magnetic induction intensity B value. In severe cases, it will cause Fryer problem

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