CONTROL SYSTEM FOR AN ELECTRIC MACHINE

• US 20100254685A1
• Filed: 03/31/2010
• Published: 10/07/2010
• Est. Priority Date: 04/04/2009
• Status: Active Grant

• Current Assignee: Dyson Technology Limited (Beeswax Holdings UK Limited)
• Original Assignee: Dyson Technology Limited (Beeswax Holdings UK Limited)
• Inventors: DAI, Hanping
• Granted Patent: US 9,225,281 B2
• Time in Patent Office: Days
• US Class Current: 388/801
• CPC Class Codes: G01D 1/00 Measuring arrangements giving results other than momentary value of variable, of general application G01D3/00 takes precedence; in tariff metering apparatus G01D4/00; transducers not specially adapted for a specific variable G01D5/00
• CPC Class Codes: G01D 15/00 Component parts of recorders for measuring arrangements not specially adapted for a specific variable
• CPC Class Codes: H02P 27/08 with pulse width modulation
• CPC Class Codes: H02P 6/14 Electronic commutators
• CPC Class Codes: H02P 6/16 Circuit arrangements for detecting position

Abstract

A control system for an electric machine, the control system including a position sensor and a drive controller. The drive controller generates one or more control signals for use in exciting a winding of the electric machine. Control signals for each electrical half-cycle of one mechanical cycle are generated by the drive controller in response to a single edge of a signal output by the position-sensor.

Claims

1. A control system for an electric machine, the control system comprising a position sensor and a drive controller, the drive controller generating one or more control signals for exciting a winding of the electric machine, wherein the drive controller generates control signals for each electrical half-cycle of one mechanical cycle in response to a single edge of a signal output by the position-sensor.

2. A control system as claimed in claim 1, wherein the drive controller averages the interval between successive edges of the position-sensor signal over at least one mechanical cycle to obtain a half-cycle time, the drive controller generates a first set of control signals in response to an edge of the position-sensor signal, and the drive controller generates one or more subsequent sets of control signals at times separated by an interval corresponding to the half-cycle time.

3. A control system as claimed in claim 1, wherein the drive controller generates control signals in response to one only of a rising edge and a falling edge of the position-sensor signal.

4. A control system as claimed in claim 1, wherein the position sensor is a Hall-effect sensor.

5. A control system as claimed in claim 1, wherein the control system comprises an inverter and a gate driver module, and the control signals generated by the drive controller are delivered to the gate drive module, and the gate driver module controls the opening and closing of switches of the inverter in response to the control signals.

6. A battery-powered product comprising an electric motor and a control system as claimed in claim 1.

7. A vacuum cleaner comprising an electric motor and a control system as claimed in claim 1.

8. A control system for an electric machine, the control system comprising a position sensor and a drive controller, the drive controller generating one or more control signals for exciting a winding of the electric machine, wherein the drive controller generates control signals for each half of an electrical cycle in response to one only of a rising edge and a falling edge of a signal output by the position sensor.

9. A control system as claimed in claim 8, wherein the drive controller averages the interval between successive edges of the position-sensor signal to obtain a half-cycle time, generates a first set of control signals in response to one only of a rising edge and a falling edge of the signal, and generates a second set of control signals subsequent to the first set of control signals at an interval corresponding to the half-cycle time.

10. A control system as claimed in claim 8, wherein the position sensor is a Hall-effect sensor.

11. A control system as claimed in claim 8, wherein the control system comprises an inverter and a gate driver module, and the control signals generated by the drive controller are delivered to the gate drive module, and the gate driver module controls the opening and closing of switches of the inverter in response to the control signals.

12. A battery-powered product comprising an electric motor and a control system as claimed in claim 8.

13. A vacuum cleaner comprising an electric motor and a control system as claimed in claim 8.