| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor control device that can achieve a high breaking property of a three-phase brushless motor.SOLUTION: There is provided a switching circuit 70 that supplies a current from a power source P to coils U, V, and W of a three-phase brushless motor 7 by switching switches 71 to 76, the switching circuit switching on/off of the switches 74 to 76 at breaking while turning off the switches 71 to 73 such that only a combination of the coil U and V at motor angles from 0° to 60° and 180° and 240°, only a combination of the coils U and W from 60° to 120° and 240° to 300°, and only a combination of the coils V and W from 120° to 180° and 300° to 360°, are short-circuited. At the moment when the motor angle reaches 0°, 120°, and 240°, respectively, an induction electromotive force having a peak waveform with higher voltage than a power source voltage is generated in the coil that is not short-circuited at the moment, and a current Ib generated by the induction electromotive force flows to the power source P through parasitic diodes 71a to 73a and is consumed.SELECTED DRAWING: Figure 8 |
