Coupling inductor and power converter

Abstract

The invention provides a coupling inductor and a power converter. The coupling inductor comprises at least two input ends, an output end, a common magnetic core, at least two first windings and at least two second windings, wherein the common magnetic core comprises at least two magnetic columns; the number of the magnetic columns corresponds to that of the input ends; each of the at least two magnetic columns is wound with a first winding and a second winding in parallel; the first windings and the second windings on the at least two magnetic columns are connected with each other between the at least two input ends and the output end to form mutually coupled inductors, so that when currents flowing into the at least two input ends are equal, the first winding and the second winding on each magnetic column generate opposite magnetic potentials. According to the technical scheme, when the currents flowing into the at least two input ends are equal, the first winding and the second winding on each magnetic column generate the opposite magnetic potentials, so that magnetic potentials generated by a common mode current offset each other, and leakage flux is reduced.

Description

technical field [0001] The invention relates to the field of circuits, in particular to a coupling inductor and a power converter. Background technique [0002] Currently, multilevel parallel converters are widely used. By using the interleaved parallel technology, the multilevel parallel converter can reduce the output ripple current and increase the output switching frequency, so the output inductance can be reduced, thereby reducing the volume and cost of the inductor. [0003] For example, taking a five-level power converter using a two-phase coupled inductor as an example, when the common mode current flows through the coils on the two magnetic legs of the coupled inductor, the directions of the magnetic fluxes generated by the coils on the two magnetic legs are opposite , therefore, the common-mode magnetic flux in the upper and lower yokes is zero, while the magnetic flux in the two magnetic columns will generate a large common-mode magnetic potential, resulting in m...

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Problems solved by technology

[0003] For example, taking a five-level power converter using a two-phase coupled inductor as an example, when the common mode current flows through the coils on the two magnetic columns of the coupled inductor, the directions of the magnetic fluxes generated by the coils on the two magnetic columns are opposite , therefore, the common-mode magnetic flux in the upper and lower yokes is zero, while the magnetic flux in the two magnetic columns will generate a large common-mode magnetic potential, resulting in magnetic flux leakage in the air, that is, the magnetic flux leakage caused by the common-mode current can not be ignored

[0004] Due to the large common mode current, there is a large leakage flux in the coupled inductor, the leakage flux will generate eddy current loss in the winding, and generate stray loss in the metal part outside the winding. At the same time, the leakage flux will also affect The normal operation of surrounding Hall sensors, current transformers (current transformer, CT) and other magnetic components

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