Constant-power electric system
AssigneeDyson Tehcnology Limited
InventorsAndrew Charlton Clothier, Tuncay Celik
Life of this patent
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Abstract
An electric system that includes a single-phase permanent-magnet electric machine and a control system for driving the electric machine. The control system sequentially excites and freewheels a winding of the electric machine so as maintain substantially constant power over an operating speed range spanning at least 10 krpm and/or an excitation voltage range extending between a minimum voltage and a maximum voltage, the minimum voltage being less than 80% of the maximum voltage. Additionally, a product comprising the electric system.
Claims23
An electric system comprising a single-phase permanent-magnet electric machine and a control system for driving the electric machine, wherein the control system sequentially excites and freewheels a winding of the electric machine, the winding is excited in advance of zero-crossings of back EMF by an advance angle, the winding is freewheeled over a freewheel angle, the control system varies the advance angle and the freewheel angle in response to changes in the speed of the electric machine so as to maintain substantially constant power over an operating speed range spanning at least 10 krpm, and the control system increases the advance angle and decreases the freewheel angle in response to an increase in the speed of the electric machine.
An electric system comprising a single-phase permanent-magnet electric machine and a control system for driving the electric machine, wherein the control system sequentially excites and freewheels a winding of the electric machine, the winding is excited by an excitation voltage in advance of zero-crossings of back EMF by an advance angle, the winding is freewheeled over a freewheel angle, and the control system varies at least one of the advance angle and the freewheel angle in response to changes in the excitation voltage so as to maintain substantially constant power over an excitation voltage range extending between a minimum voltage and a maximum voltage, the minimum voltage being less than 80% of the maximum voltage.
An electric system comprising a single-phase permanent-magnet electric machine and a control system for driving the electric machine, wherein the control system sequentially excites and freewheels a winding of the electric machine, the winding is excited in advance of zero-crossings of back EMF by an advance angle, the winding is freewheeled over a freewheel angle, and the control system varies at least one of the advance angle and the freewheel angle in response to changes in the speed of the electric machine so as to maintain substantially constant power over an operating speed range having a minimum greater than 60 krpm and a maximum greater than 80 krpm.
Dependencies are inferred from the claim text.