| 摘要 |
A method of operating a brushless motor having a stationary assembly with at least two different energizable windings for producing spaced apart magnetic fields in time sequence, and a rotor adapted to rotate in response to the magnetic fields. The method includes the steps of simulating rotor position in accordance with the back emf condition of at least one winding, energizing a selected one of the windings in accordance with the simulated rotor position, sensing an underspeed condition when the motor speed is less than a minimum value for a length of time, and preventing energization of any of the windings when the motor speed is less than the minimum value for the length of time. An electrically commutated motor controller apparatus controls the speed of a variable speed motor compressor driven by an electrically commutated motor. A controller circuit includes a circuit for producing feedback signals representative of a back emf of the motor. A compressor speed circuit generates actual compressor speed signals from the feedback signals produced by the controller circuit. A duty cycle generator produces a speed control signal as a function of the actual compressor speed signals, and the speed control signal is transmitted to the controller circuit for adjusting the speed of the electrically commutated motor driven compressor. Other motor controls, refrigeration systems and methods of control and operation are also disclosed.
|
