VARIABLE MOTOR DRIVE SYSTEM FOR A RESERVOIR WITH CIRCULATING FLUID

• US 20100017954A1
• Filed: 07/15/2009
• Published: 01/28/2010
• Est. Priority Date: 07/24/2008
• Status: Active Grant

• Current Assignee: Nidec Motor Corporation (Nidec Corporation)
• Original Assignee: Emerson Electric Company
• Inventors: Clark, Bret S., Sullivan, Michael P., Peterson, Gregory A., Morgan, Donald E.
• Granted Patent: US 8,226,374 B2
• Time in Patent Office: Days
• US Class Current: 4/541.200
• CPC Class Codes: A61H 2201/1207 with electric or magnetic drive
• CPC Class Codes: A61H 2201/5007 computer controlled
• CPC Class Codes: A61H 2201/5046 Touch screens
• CPC Class Codes: A61H 33/005 Electrical circuits therefor
• CPC Class Codes: A61H 33/0087 Therapeutic baths with agitated or circulated water
• CPC Class Codes: A61H 33/60 Components specifically designed for the therapeutic baths of groups A61H33/00 plumbing E03C1/00
• CPC Class Codes: A61H 33/601 Inlet to the bath
• CPC Class Codes: A61H 33/6068 Outlet from the bath

Abstract

A motor drive for an electric motor of a variable fluid circulating system includes a processing module and a power module. The processing module receives a signal profile and generates a control signal based on the signal profile. A power module generates a carrier signal based on the control signal and a direct current (DC) voltage. The power module pulse width modulates the carrier signal to generate a drive signal in the electric motor that matches the signal profile. The power module powers the electric motor based on the drive signal to adjust injection of a fluid into a reservoir.

Claims

1. A motor drive for an electric motor of a variable fluid circulating system comprising:

a processing module that receives a first signal profile and generates a control signal based on the first signal profile; and

a power module that generates a carrier signal based on the control signal and a direct current (DC) voltage,

wherein the power module pulse width modulates the carrier signal to generate a first drive signal in the electric motor that matches the first signal profile, and

wherein the power module powers the electric motor based on the first drive signal to adjust injection of a fluid into a reservoir.

2. The motor drive of claim 1, wherein the power module adjusts amplitude of at least one of the carrier signal and the first drive signal based on the control signal.

3. The motor drive of claim 1, wherein the power module adjusts offset of at least one of the carrier signal and the first drive signal based on the control signal.

4. The motor drive of claim 1, wherein the power module adjusts frequency of at least one of the carrier signal and the first drive signal based on the control signal.

5. The motor drive of claim 1, wherein the power module adjusts phase modulation of at least one of the carrier signal and the first drive signal based on the control signal.

6. The motor drive of claim 1, wherein the power module adjusts period of at least one of the carrier signal and the first drive signal based on the control signal.

7. The motor drive of claim 1, wherein the power module pulse width modulates the carrier signal to generate the first drive signal to match the first signal profile during a first time period, and

wherein the power drive module generates a second drive signal to match the second signal profile during a second time period.

8. The motor drive of claim 7, wherein the first drive signal has a first amplitude and the second drive signal has a second amplitude, and

wherein the first amplitude is different than the second amplitude.

9. The motor drive of claim 7, wherein the first drive signal has a first offset and the second drive signal has a second offset, and

wherein the first offset is different than the second offset.

10. The motor drive of claim 7, wherein the first drive signal has a first frequency and the second drive signal has a second frequency, and

wherein the first frequency is different than the second frequency.

11. The motor drive of claim 7, wherein the first drive signal has a first period and the second drive signal has a second period, and

wherein the first period is different than the second period.

12. The motor drive of claim 1, wherein said power module superimposes a waveform onto the carrier signal when pulse width modulating the carrier signal to generate the drive signal.

13. The motor drive of claim 12, wherein the waveform is one of a sine, waveform, a square waveform, a triangle waveform, and a stepped waveform.

14. The motor drive of claim 1, wherein the power module cycles the electric motor between ON and OFF states to generate the drive signal.

15. The motor drive of claim 1, wherein the power module cycles the electric motor between M ON states to generate the drive signal, where M is an integer greater than 1.

16. The motor drive of claim 1, wherein the power module cycles the electric motor to convert the DC voltage to generate the carrier signal, which is a 3-phase alternating current (AC) signal.

17. The motor drive of claim 1, wherein the power module limits speed, amplitude, offset, frequency and period of the electric motor.

18. The motor drive of claim 1, wherein the power module generates and pulse width modulates the carrier signal to vary pressure, flow volume and flow rate of the fluid injected into the reservoir based on the drive signal.

19. A variable fluid circulating system for at least one of a spa, a tub, and a pool comprising:

a user interface that generates a first control signal;

a motor drive comprising;

a processing module that comprises a microprocessor that generates a second control signal based the first control signal; and

a power module that generates a carrier signal based on the second control signal and a direct current (DC) voltage,

wherein the power module pulse width modulates the carrier signal to generate a first drive signal with a first signal profile;

an electric motor that is powered by the pulse width modulated carrier signal and that generates the first drive signal based on the pulse width modulated carrier signal; and

a pump that receives the first drive signal via a mechanical coupling that is connected to the electric motor.

20. The variable fluid circulating system of claim 19, further comprising memory that stores N signal profiles, where N is an integer,

wherein the processing module selects one of the N signal profiles based on the first control signal and generates a second control signal based the selected one of the N signal profiles.

21. The variable fluid circulating system of claim 20, wherein the power module pulse width modulates the carrier signal to generate a second drive signal that matches the selected one of the N signal profiles.

22. The variable fluid circulating system of claim 21, wherein the power module generates the first drive signal during a first time period, and

wherein the power drive module generates the second drive signal during a second time period.

23. The variable fluid circulating system of claim 22, wherein the first drive signal has a first amplitude, a first offset, a first frequency, and a first period,

wherein the second drive signal has a second amplitude, a second offset, a second frequency, and a second period, and

wherein the first amplitude is different than the second amplitude, the first offset is different than the second offset, the first frequency is different than the second frequency, and the first period is different than the second period.

24. The variable fluid circulating system of claim 19, wherein the power module pulse width modulates the carrier signal to generate the first drive signal that is amplitude modulated and frequency modulated based on the pulse width modulated carrier signal.

25. The variable fluid circulating system of claim 24, wherein speed of the electric motor varies based on the amplitude modulation and the frequency modulation.

26. The variable fluid circulating system of claim 25, wherein the power module adjusts variance in the DC voltage based on the first control signal, and

wherein rate of change in the speed varies based on the variance.

27. The variable fluid circulating system of claim 19, wherein the pump injects and varies the flow of a fluid into a reservoir of the one of the spa, the tub and the pool based on the drive signal.

28. The variable fluid circulating system of claim 19, wherein the pump injects and varies pressure, flow volume and flow rate of a fluid injected into a reservoir of the one of the spa, the tub and the pool based on the drive signal.

29. The variable fluid circulating system of claim 19, wherein the user interface comprises a selector, and

wherein the power module adjusts amplitude, offset and frequency of the drive signal based on state of the selector.

30. The variable fluid circulating system of claim 29, wherein the processing module selects one of N signal profiles based on change in state of the selector, where N is an integer greater than 1, and

wherein the N signal profiles have N distinct amplitudes, N distinct offsets and N distinct frequencies.