Control of an electric machine
AssigneeDyson Technology Limited
InventorsAndrew Charlton Clothier, Tuncay Celik
Life of this patent
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Abstract
A method of controlling an electric machine that includes sequentially exciting and freewheeling a winding of the electric machine. The winding is excited by an excitation voltage and is freewheeled over a freewheel angle. The method then includes varying the freewheel angle in response to changes in the excitation voltage. Additionally, a control system for an electric machine, and a product incorporating the control system and electric machine.
Claims15
A method of controlling an electric machine, the method comprising:
- sequentially exciting and freewheeling a winding of the electric machine, wherein the winding is excited by an excitation voltage and is freewheeled over a freewheel angle;
- and
- varying the freewheel angle in response to changes in the excitation voltage,
- wherein the method comprises decreasing the freewheel angle in response to a decrease in excitation voltage.
A method of controlling an electric machine, the method comprising:
- sequentially exciting and freewheeling a winding of the electric machine, wherein the winding is excited by an excitation voltage and is freewheeled over a freewheel angle;
- and
- varying the freewheel angle in response to changes in the excitation voltage,
- wherein the method comprises storing a lookup table of control values for a plurality of voltages, selecting from the lookup table a control value according to the level of the excitation voltage, and freewheeling the winding for a period of time defined by the control value.
A method of controlling an electric machine, the method comprising:
- sequentially exciting and freewheeling a winding of the electric machine, wherein the winding is excited by an excitation voltage and is freewheeled over a freewheel angle;
- and
- varying the freewheel angle in response to changes in the excitation voltage,
- wherein each electrical half cycle comprises a single drive period and a single freewheel period, and the method comprises exciting the winding during the drive period and freewheeling the winding during the freewheel period.
A method of controlling an electric machine, the method comprising:
- sequentially exciting and freewheeling a winding of the electric machine, wherein the winding is excited by an excitation voltage and is freewheeled over a freewheel angle;
- and
- varying the freewheel angle in response to changes in the excitation voltage and in response to changes in speed of the electric machine,
- wherein the method comprises decreasing the freewheel angle in response to one of a decrease in excitation voltage and an increase in speed.
Dependencies are inferred from the claim text.