Method and device for compensating the residual current watté in the networks polyphase with protection to the high voltage inductive in the case of accidental earthing

摘要

368,255. Protective cut-out arrangements. AKT.-GES. BROWN, BOVERI, ET CIE, Baden, Switzerland. Oct. 23, 1930, No. 31914. Convention date, Feb. 7. [Class 38 (v).] In the protection of polyphase high-tension networks by means of limiting reactances, in addition to the reactance L connected to the line-connected transformer or choke T to deal with the capacitycurrent component of the leakage current to earth, an additional impedance Z is connected, on fault, through selective relays Ra, Rb, Rc to the line to deal with the power component of the leakage current. In the arrangement shown, the impedance Z is connected to the free ends of subsidiary windings a, a1, b, b1, c, cl which are connected to the corners of a delta-connected transformer or choke H across the phases. In the event of an earth fault, the loss of voltage on one of the phases causes the closure of one of the relays and the connection of the impedance Z to a suitable point on the choke H. An auxiliary star-connected winding with neutral point 0 may be connected with the winding Hand takes the place of the choke T.