Fault diagnosis system for rotor winding of rotary electric machine

摘要

A fault diagnosis system for a rotor winding of rotary electric machines is disclosed, in which the rotor winding of rotary field type (1) is excited in DC fashion by an excitation circuit (2, 3, 4, 9), on which an AC voltage is superposed, the impedance of the rotor winding (1) is calculated from the current and voltage of the AC portion flowing in the rotor winding (1), and the resulting impedance is compared with a reference impedance thereby to decide a fault, if any, of the rotor winding (1), thus making possible accurate diagnosis of a rotary electric machine even while it is running.