DEVICE FOR PROTECTING AC ELECTRIC ENGINE AGAINST ABNORMAL MODES OF OPERATION Russian patent published in 1996 - IPC

FIELD: protection of three-phase async and sync electric engines of generators against impermissible heating of rotor windings. SUBSTANCE: device has current transformers 1, rectifier 2 to which posistors 3 and stabilizer diode 13 are connected, amplitude detector 11 which has input connected to posistors, threshold unit 5 which has operation threshold pre-set input connected with stabilizing diode, and actuating member connected to output of threshold unit. Operation input of threshold unit 5 is connected with output of amplitude detector. EFFECT: improved efficiency of protection. 4 cl, 2 dwg