DISCRIMINATOR FOR DETECTING ABNORMALITY IN POWER SOURCE SYSTEM

摘要

PURPOSE:To prevent the outbreak of accidents by winding a coil on a grounding wire, taking in the induced current generated in the coil and detecting a corona discharge state. CONSTITUTION:Electricity is supplied from a power receiving transformer 1 to respective induction motor 2. A coil 7a is wound on the grounding wire 6 of a grounding transformer 5 and the induced current generated in the coil is drawn out as a corona signal by a corona detector 7. After said signal is converted 8 to a voltage, the voltage is fed through an amplifier 9 and an HPF10, and the corona signal and the high band noises in the prescribed time duration are stored in a memory 11 in accordance with the output of a constant phase controller 13. The outputs of the memory 11 are added and averaged 14 successively to remove random noises, and are applied to abnormal level setters 15 and 16. When the times of high abnormal level exceeds set values, a starter 18 is started to operate a recorder 20, a time display device 21, and an alarm 22. When the corona signal is of a low level, the signals are recorded with a memory 19.