| 摘要 |
PURPOSE:To readily discriminate between a normal motor and a malfunctioned motor by moving an average vector of currents reversely to a vector point of the malfunctioned motor. CONSTITUTION:Voltage signals Sa corresponding to the average vector Ia/n of currents flowed through many motors are regulated in magnitude and phase by a phase delay circuit 13 and converted to voltage signals Saa. An adder 11 adds the signal Saa and voltage signals Si corresponding to the currents Isl-Isn flowed to the respective motors and outputs a signal DELTASai. A malfunction discriminator 12 outputs a malfunction signal Abi when the value of the signal DELTASai is larger than the reference signal Ref. Since the average vector of the current is moved to a broken line Iaa/n, a circle E which includes a normal motor becomes substantially the same radius as a circle C, and can readily discriminate between the normal motor and the malfunctioned motor. |
