| 摘要 |
A method of determining the position of a rotor of a permanent-magnet motor. The method uses two different schemes to determine the position of the rotor. A first scheme is used when the rotor rotates within a first speed range, by sequentially exciting and freewheeling a winding of the motor, measuring a parameter that depends on the rate of change of current in the winding, and comparing the parameter against a threshold. A second scheme is used when the rotor rotates within a second speed range, by generating a voltage signal that is proportional to the voltage across the winding, generating a further voltage signal that depends on the rate of change of current in the winding, and comparing the two signals. |
