Three-phase common mode reactor

Abstract

The invention relates to a three-phase common-mode reactor and aims to provide the three-phase common-mode reactor. The three-phase common-mode reactor is used in a three-phase inversion circuit with relatively large common-mode harmonic component, and the effect of filtering the common-mode harmonic can be achieved very well. The three-phase common-mode reactor comprises an upper iron yoke, two iron core posts wound with coils and a lower iron yoke, wherein the two iron core posts wound with the coils are arranged in parallel between the upper iron yoke and the lower iron yoke, three coils with same turns are wound around each the iron core post wound with the coils, the coils are isolated, and a group of dotted ends on the three coils of the iron core post are respectively connected with a group of non-dotted ends of the three coils of another iron core post.

Description

technical field [0001] The present invention relates to a kind of electric power equipment, in particular, relates to a kind of three-phase common mode reactor. Background technique [0002] In the common three-phase inverter output circuit, the proportion of zero-sequence components is not large, and only a three-phase sine wave filter reactor needs to be connected to the output side of the inverter. When some special three-phase inverter circuits have large common-mode harmonic content, conventional three-phase reactors cannot generate large common-mode inductance and play a role in filtering common-mode harmonics. [0003] A conventional three-phase reactor consists of three iron core columns wound with coils and upper and lower iron yokes. The conventional method is to add a ring core to the three-phase line, but the magnetic conductivity of the ring core is relatively low, and the common mode inductance is difficult to increase; moreover, the ring core is not easy to f...

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Problems solved by technology

The conventional method is to add a ring core to the three-phase line, but the magnetic conductivity of the ring core is relatively low, and the common mode inductance is difficult to increase; moreover, the ring core is not easy to fix when it is placed on the cable, so this kind of added Reactors with toroidal cores can only be used when the required common mode inductance is small

When the three-phase circuit contains high zero-sequence common-mode components, the vector sum of the magnetic fluxes in the three iron core columns wound with coils is not zero, and the zero-sequence common-mode harmonics cannot be filtered out by using conventional three-phase reactors. Wave

If three-phase four-column reactors, three-phase five-column reactors, or three single-phase reactors are used instead, although zero-sequence common-mode inductance can be generated, its common-mode inductance is equivalent to that of three-phase differential-mode inductance, and it is difficult to meet the requirements of the above circuit. The inductance required to filter the common mode harmonic content in the circuit

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