INDUCTION MOTOR CURRENT MONITORING PROCESS Russian patent published in 1995 - IPC

FIELD: electric measurements. SUBSTANCE: RMS value of input current is converted into d.c. signal which is converted into digital code, and digital equivalents of current under measurement are compared with tolerated values; prior to current conversion into digital code, operations are introduced for measuring supply voltage, subtracting rated voltage from supply voltage, shaping signal equal to product of difference signal by input current signal, determining obtained signal to supply voltage signal ratio, subtracting this signal from input current signal. EFFECT: improved validity of induction motor input current monitoring due to elimination of effect of supply voltage measurement on check results when testing motor at no load and short-circuit running. 1 dwg