PROCESS LOCATING POINT OF SINGLE-PHASE SHORT-CIRCUIT IN CABLE LINES LAID IN GROUND Russian patent published in 1999 - IPC

FIELD: electrical engineering. SUBSTANCE: process locating point of single-phase short-circuit in cable lines laid in ground consists in preliminary finding of supposed point of fault with the use of any distance measuring methods, in placement of faulty conductor and cable sheath in series with circuit going from audio frequency generator to conductor and cable sheath, in energizing of primary winding of variable-ratio transformer which secondary winding incorporating phase-shifting network connected in parallel is placed between ground and sheath at cable end nearest to generator. Sensor with radio transmitter is positioned in addition on ground surface above cable at point of supposed fault. Sensor is positioned do that it responds predominantly to field of solitary currents. Information on parameters of field of solitary current is transmitted over radio communication to point where variable-ratio transformer is located. Field of solitary current is compensated at supposed point of fault by adjustment of value and phase of voltage of transformer and by registration of zero value of field of solitary current. Then cable locator is moved along cable routing and change of electromagnetic field created by currents flowing through cable is recorded. EFFECT: increased precision of location of points of single-phase short-circuits in cable lines laid in ground. 1 dwg