METHOD OF DIAGNOSING COMMUTATION OF ARMATURE WINDINGS AND QUALITY OF POWER SUPPLY TO DIRECT CURRENT COMMUTATOR MOTORS Russian patent published in 2009 - IPC G01R31/06 

FIELD: electrical engineering.

SUBSTANCE: invention relates to diagnosis of electrical machines. Two variable inductance transducers are installed inside the collector chamber near the brush holder. The transducers have identical frequency characteristics and are connected towards each other. The transducers lie at a small distance from each other. During operation of the motor, signals of induced electromotive force (EMF) reach the input of a voltmetre from the transducers. These signals are subtracted and a differential signal of EMF induced in the transducers is obtained. Quality of commutation is determined from the effective value of differential signal. To evaluate quality of power supply, spectral analysis of the differential signal is done. Absence in the differential signal spectrum of harmonic components, which are multiples of the frequency of the alternating current network at the input of the supply rectifier, corresponds to absence of rippling of the supply voltage of the motor, while their presence indicates the need for monitoring and regulating parametres of the elements of the supply rectifier: diodes, rectifier valves, capacitors, resistors.

EFFECT: provision for objective evaluation of quality of commutation of armature windings with simultaneous evaluation of quality of power supply, as well as simplification of the measuring and analysis procedures.

3 cl, 4 dwg