DIFFERENTIAL PROTECTION METHOD FOR CURRENT CONVERTER AND RELAY PROTECTION DEVICE Russian patent published in 2018 - IPC H02H7/10 

FIELD: electrical engineering.

SUBSTANCE: differential protection method for current source converter comprises steps of: sampling, by a relay protection device, secondary side currents of current transformers on two sides of a protected current source converter, to obtain incomer-side three-phase currents, and outgoer-side three-phase currents; rectifying the incomer-side three-phase currents and the outgoer-side three-phase currents, to obtain an incomer-side input current and an outgoer-side output current which are equivalent; converting the incomer-side input current and the outgoer-side output current according to a current ratio of the current transformers on the two sides, to obtain a transient differential current and a transient restraint current; obtaining a differential current and a restraint current according to the transient differential current and the transient restraint current; and achieving differential protection according to the differential current and the restraint current. Embodiments of the present invention further disclose a relay protection device correspondingly.

EFFECT: ensuring reliable differential protection of current converters.

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