Patent ID: 6112156
Filing Date: 2000-08-29
Classification: G01R

Abstract:
A motor abnormality detection apparatus for detecting an abnormality of a motor, comprising:a current measurer for measuring current flowing through said motor;a voltage measurer for measuring voltage applied to said motor;a motor state detector for detecting an operation state of said motor;a current estimator for estimating current flowing through said motor based on the measured value of said voltage measurer and the detection result of said motor state detector; andan abnormality detector for detecting abnormalities of said motor based on the measured value of said current measurer and the estimated value of said current estimator;wherein said current estimator includes means for using an observer which is expressed by the following equation: ##EQU7## in which R is a resistance of a motor coil, L is an inductance of the motor coil, K.sub.f is a counter-electromotive force constant, .omega. is an angular velocity of a motor rotor, V.sub.d and V.sub.q are voltages of d-q axis, i.sub.d and i.sub.q are currents of d-q axis, and a symbol is an estimated value of a corresponding variable.