Transformer magnetic bias prevention circuit of bidirectional transducer

Abstract

The invention discloses a transformer magnetic bias prevention circuit of a bidirectional transducer. The transformer magnetic bias prevention circuit comprises a primary-side bridge circuit B, a secondary-side bridge circuit C and a resonant network A; the resonant network A comprises a power transformer Tr, a resonant inductor Lr and a blocking capacitor Cr; the primary-side bridge circuit B comprises a switch tube Q1, a switch tube Q2, a switch tube Q3 and a switch tube Q4; the secondary-side bridge circuit C comprises a switch tube Q5, a switch tube Q6, a witch tube Q7 and a switch tube Q8. By the arrangement, the problem about transformer magnetic bias is solved ingeniously; the blocking capacitor is added in the resonant network and can naturally perform reverse callback on the situation that volt-second products of positive and negative cycles are not equal, a natural negative feedback is formed, a magnetic core of the transformer can be sustained in a state of volt-second equilibrium, and magnetic bias of the transformer can be well prevented.

Description

technical field [0001] The invention relates to a transformer protection circuit, in particular to a circuit for preventing transformer bias magnetization of a bidirectional converter. Background technique [0002] With the rapid development of smart grid and energy interconnection, products that convert and transmit electric energy in two directions have become market hotspots in this field. The power transformer is the core device of the bidirectional converter, and the reliable and efficient operation of the transformer is the top priority of the converter. However, due to the discreteness of the parameters of the power circuit and the driving circuit, the volt-second products of the positive and negative cycles of the transformer are often not equal. After several switching cycles, the deviation of the volt-second products will gradually accumulate. As the voltage increases, it will eventually lead to serious bias magnetization of the transformer, which will lead to mag...

AI Technical Summary

Problems solved by technology

However, due to the discreteness of the parameters of the power circuit and the driving circuit, the volt-second products of the positive and negative cycles of the transformer are often not equal. After several switching cycles, the deviation of the volt-second products will gradually accumulate. It will eventually lead to severe magnetic bias of the transformer, which will lead to magnetic saturation and cause the transformer to burn out due to overcurrent

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