Control of a brushless motor
AssigneeDyson Technology Limited
InventorsAndrew Charlton Clothier, Stephen Greetham, Nicholas Dalibor Tuftnell
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 having a ripple of at least 50%, exciting a winding of the motor with the rectified voltage, and performing a first process or a second process in response to current in the winding exceeding a threshold that is proportional to the rectified voltage. The first process includes freewheeling the winding, while the second process includes continuing to excite the winding for an overrun period and freewheeling the winding at the end of the overrun period. Additionally, a control system that implements the method, and a motor system that incorporates the control system.
Claims16
A method of controlling a brushless motor, the method comprising:
- rectifying an alternating voltage to provide a rectified voltage having a ripple of at least 50%;
- exciting a winding of the motor with the rectified voltage;
- and
- performing one of a first process and a second process in response to current in the winding exceeding a threshold proportional to the rectified voltage,
- wherein the first process comprises freewheeling the winding, and the second process comprises continuing to excite the winding for an overrun period and freewheeling the winding at the end of the overrun period.
Dependencies are inferred from the claim text.