ELECTROMAGNETIC COMPENSATOR OF CURRENT OF THIRD HARMONIC IN THREE-PHASE FOUR-WIRE NETWORKS Russian patent published in 2019 - IPC H02J3/01 

FIELD: electrical engineering.

SUBSTANCE: third-harmonic electromagnetic current compensator contains a three-phase half-wave rectifier, four current transformers, one of which is connected by its primary winding to a neutral wire, and the other three – in the phase wires of the network, characterized in that it additionally introduced a filter with a bandwidth of 150 Hz, three current relays and three circuits of series-connected capacitors and a resistor, the windings of the three current relays are connected in parallel with the secondary windings of three current transformers included in the phase conductors of the network, and series-connected disconnecting contacts of three current relays shunt the secondary winding of a current transformer connected to the neutral wire of the network, and parallel to the windings of three current relays are connected circuits of series-connected capacitor and resistor, the beginnings of the secondary windings of three current transformers included in the phase conductors of the network are connected to a common point and connected to the beginning of the secondary winding of the current transformer included in the neutral wire, and the ends of three current transformers included in the phase conductors of the network are connected to the anodes of a three-phase half-wave rectifier, cathodes of which are connected to a common point and connected through a filter with a bandwidth of 150 Hz to the end of the secondary winding of a current transformer included in the neutral wire of the network.

EFFECT: improving the accuracy of the third harmonic compensation.

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