PROTECTION DEVICE AGAINST SINGLE-PHASE GROUND FAULT OF STATOR WINDING SYNCHRONOUS GENERATOR WORKING IN BLOCK WITH TRANSFORMER

Abstract

There has been offered a device that protects against single-phase ground fault of the stator winding of the synchronous generator operating in a block with a transformer which calculates and responses to the current in the location of the ground fault, by using the combined principle of superposition of  direct current to the circuit comprising the stator winding insulation for determining resistance stator winding insulation with respect to ground, using discharge energy previously charged capacitor for determining the transitional resistance at the site of an earth fault, zero-sequence voltage monitoring and accounting of the capacity of the stator winding insulation with respect to ground.