Patent ID: 8766589

Claim:
A motor control unit comprising: a motor control signal output unit that outputs a motor control signal; a drive circuit that supplies driving current to a motor based on the motor control signal; and an abnormality detection unit that detects a current-carrying failure in an electric power supply path to the motor based on a voltage parameter corresponding to a voltage that is applied to the motor, wherein the abnormality detection unit determines whether a first determination condition is satisfied, the first determination condition including a condition that an actual current value that indicates an electric current actually supplied to the motor is smaller than or equal to a predetermined current value that indicates a non-current carrying state and the voltage parameter is higher than or equal to an upper limit of a predetermined range corresponding to the predetermined current value, and the abnormality detection unit determines whether a second determination condition is satisfied, the second determination condition including a condition that the actual current value is smaller than or equal to the predetermined current value and the voltage parameter is lower than or equal to a lower limit of the predetermined range, the abnormality detection unit measures a first duration that is a duration of time that a state where the first determination condition is satisfied continues, and a second duration that is a duration of time that a state where the second determination condition is satisfied continues, an inductive voltage value calculation unit that determines an inductive voltage value that is generated in the motor, and when the first duration or the second duration exceeds a predetermined reference period that is set based on a rotation period of the motor when the motor is rotating at a high speed that the voltage parameter falls outside the predetermined range due to an influence of inductive voltage, the abnormality detection unit determines that a current-carrying failure has occurred.