Control of a brushless motor
AssigneeDyson Technology Limited
InventorTuncay CELIK
Life of this patent
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Abstract
A method of controlling a brushless motor that includes rectifying an alternating voltage to provide a rectified voltage, and exciting a winding of the motor with the rectified voltage. The winding is excited in advance of predetermined rotor positions by an advance period and is excited for a conduction period over each electrical half-cycle of the motor. The length the advance period and/or the conduction period is defined by a waveform that varies periodically with time. The method then includes adjusting the phase of the waveform relative to the alternating voltage in response to a change in one of motor speed and RMS value of the alternating voltage. Additionally, a control system that implements the method, and a motor system that incorporates the control system.
Claims20
A method of controlling a brushless motor, the method comprising:
- rectifying an alternating voltage to provide a rectified voltage;
- exciting a winding of the motor with the rectified voltage, the winding being excited in advance of predetermined rotor positions by an advance period and being excited for a conduction period over each electrical half-cycle of the motor, the length of at least one of the advance period and the conduction period being defined by a waveform that varies periodically with time;
- and
- adjusting the phase of the waveform relative to the alternating voltage in response to a change in one of motor speed and RMS value of the alternating voltage.
Dependencies are inferred from the claim text.