A high-frequency center-tapped planar transformer in a half-bridge llc resonant converter

Abstract

The invention discloses a high-frequency center tap planar transformer in a half-bridge LLC resonant converter. Eight layers of structures are adopted, primary side windings are located in the first layer, the third layer, the sixth layer and the eighth layer, two secondary side windings are located at the second layer, the seventh layer, the fourth layer and the fifth layer respectively, primaryside additional windings comprise two rectangular additional windings, the windings at the first layer, the third layer, the fifth layer and the seventh layer are in series connection to constitute anadditional winding, the windings at the second layer, the fourth layer, the sixth layer and the eighth layer are in series connection to constitute another additional winding, two adjacent layers ofadditional windings cross with each other and are wound completely right oppositely, so that equivalent inductance Lr' and equivalent capacitance Cr' between the two additional windings replace independent resonant inductance Lr and resonant inductance Cr in a resonant network, magnetic inductance Lm is provided by a center tap planar transformer, and needed magnetic inductance values are obtainedby grinding gaps of a magnetic core; the primary side windings or the secondary side windings are located in the corresponding rectangular additional windings of the layer respectively.

Description

technical field [0001] The invention relates to a planar transformer, in particular to a high-frequency intermediate-tap planar transformer (L-C-L-T integrated high-frequency intermediate-tap transformer) in a half-bridge LLC resonant converter, which belongs to the field of integrated circuits. Background technique [0002] At present, power converters used in communication power supplies, server DC / DC power supplies and distributed power systems all have requirements for high power density, high efficiency and high reliability. In terms of high power density, how to reduce the size of the power converter has become the focus of research. Among them, the volume of the magnetic element accounts for about 30% of the volume of the power converter, which has become a bottleneck for the further development of the power converter. In fact, the most effective way to improve the power density is to increase the operating frequency of the power converter and reduce the volume of th...

AI Technical Summary

Problems solved by technology

Usually, the leakage inductance of the planar transformer is not enough to meet the requirements of the resonant inductance Lr, and an additional inductance is required to form the resonant inductance Lr

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