| 摘要 |
A tracking circuit and method are disclosed for tracking an orientation of a rotor of a motor, such as a three-phase sensorless, synchronous, sine wave permanent-magnet motor, during a loss of source power to a motor drive. The circuit comprises an electrical energy store for generating a drive signal during periods of loss of source power, and a phase locked loop, which is arranged to receive as inputs the drive signal and an induced signal generated during rotation of the rotor during the periods of loss of source power, so that variations in the drive signal become locked to variations in the induced signal. The method comprises storing electrical energy in the store during periods of source power supply to the motor drive and generating a drive signal from the electrical energy store during periods of loss of source power to the motor drive. The method further comprises varying the drive signal in dependence of an induced signal generated by the rotation of the rotor during a loss of source power to the motor drive, to track the orientation of rotor. |
