Differential Protection of Dry - Type Transformer

For the prefabricated compact transformer device, the dry-type transformer differential protection is the main transformer protection is installed according to the principle of circulating current. Transformer differential protection is mainly used to protect two-winding or three-winding transformer windings within and lead to the phase of the occurrence of a variety of short-circuit fault, but also can be used to protect the transformer single-phase inter-turn short circuit fault.
25kva pole mounted transformer are installed on both sides of the winding transformer, the secondary side of which is connected according to the circulating current method, that is, if the same level side of both sides of the current transformer is toward the bus side, the same level terminal is connected, Between the two lines connected in parallel current relay. The current flowing through the relay coil is the secondary current difference of the current transformer on both sides, which means that the differential relay is connected to the differential circuit.