Flow control

• US 10,415,569 B2
• Filed: 10/03/2017
• Issued: 09/17/2019
• Est. Priority Date: 08/26/2004
• Status: Active Grant

• Current Assignee: Danfoss Power Electronics A/S (Danfoss A/S), Pentair Water Pool And Spa Incorporated (Pentair Plc (Ireland))
• Original Assignee: Pentair Water Pool And Spa Incorporated (Pentair Plc (Ireland))
• Inventors: Stiles, Jr., Robert W., Berthelsen, Lars Hoffmann, Westermann-Rasmussen, Peter, Kjaer, Gert, Lungeanu, Florin
• Primary Examiner(s): Bertheaud, Peter J
• Application Number:
  US15/724,232
• Publication Number:
  US 20180023574A1
• Time in Patent Office: 714 Days
• Field of Search: 417 20, 417 22, 417 441, 417 42, 417 43
• CPC Class Codes: F04B 2203/0208 Power
• CPC Class Codes: F04B 2203/0209 Rotational speed
• CPC Class Codes: F04B 2205/05 Pressure after the pump outlet
• CPC Class Codes: F04B 2205/09 Flow through the pump
• CPC Class Codes: F04B 49/065 and making use of computers
• CPC Class Codes: F04B 49/106 Responsive to pumped volume
• CPC Class Codes: F04B 49/20 by changing the driving speed
• CPC Class Codes: F04B 49/22 by means of valves F04B49/03 takes precedence
• CPC Class Codes: F04D 13/06 the pump being electrically driven
• CPC Class Codes: F04D 15/0066 by changing the speed, e.g. of the driving engine
• CPC Class Codes: F04D 15/0227 Lack of liquid level being detected using a flow transducer
• CPC Class Codes: F04D 15/0236 Lack of liquid level being detected by analysing the parameters of the electric drive, e.g. current or power consumption

Abstract

A pumping system for at least one aquatic application includes a motor coupled to a pump and a controller in communication with the motor. The controller is adapted to determine a first motor speed of the motor, determine a reference power consumption using a reference flow rate and a curve of speed versus power consumption for the reference flow rate, and generate a difference value between the reference power consumption and a present power consumption. The controller drives the motor to reach a steady state condition at a second motor speed based on the difference value.

Claims

1. A pumping system for at least one aquatic application, the pumping system comprising:

a motor coupled to a pump; and

a controller in communication with the motor;

the controller adapted to determine a first motor speed of the motor;

the controller adapted to determine a reference power consumption using a reference flow rate and a curve of speed versus power consumption for the reference flow rate;

the controller adapted to generate a difference value between the reference power consumption and a present power consumption;

the controller driving the motor to reach a steady state condition at a second motor speed based on the difference value.

2. The pumping system of claim 1, wherein the controller is adapted to determine the reference flow rate for use with the curve by at least one of calculation, a look-up table, a graph, and/or a curve.

3. The pumping system of claim 2, wherein the reference flow rate is based on at least one of a volume of the at least one aquatic application, a number of turnovers desired per day, and/or a time range that the pumping system is permitted to operate.

4. The pumping system of claim 1 and further comprising a user interface in communication with the controller, wherein the controller is adapted to retrieve a reference flow rate for use with the curve from the user interface.

5. The pumping system of claim 1 and further comprising a sensor configured to measure a present shaft speed of the motor, wherein the first motor speed is determined from the present shaft speed.

6. The pumping system of claim 1, wherein the controller is adapted to determine the present power consumption based on at least one of a current and/or a voltage provided to the motor.

7. The pumping system of claim 1, wherein the controller is adapted to determine the present power consumption based on at least one of a power factor, a resistance, and/or a friction of the motor.

8. The pumping system of claim 1, wherein the controller is adapted to use at least one of integral, proportional, proportional-integral, proportional-derivative, and proportional-integral-derivative control to generate the second motor speed based on the difference value.

9. The pumping system of claim 1, wherein the controller is adapted to limit the second motor speed based on a predetermined range of relative change in motor speed as compared to the first motor speed.

10. The pumping system of claim 1, wherein the controller drives the motor to reach the steady state condition at the second motor speed based on the difference value and an integration constant.

11. The pumping system of claim 10, wherein the integration constant is dependent on a magnitude of the difference value.

12. A method of controlling a pumping system comprising a controller, a motor, and a pump, the controller in communication with the motor, the motor coupled to the pump, the method comprising:

determining, using curves of speed versus power consumption for discrete flow rates, a reference power consumption based on a first motor speed of the motor and a reference flow rate; and

driving the motor to reach a steady state condition at a second motor speed based on a difference value between the reference power consumption and a present power consumption.

13. The method of claim 12 and further comprising determining the first motor speed directly from a sensor reading a present shaft speed.

14. The method of claim 12 and further comprising determining the reference flow rate based on at least one of a volume of at least one aquatic application, a number of turnovers desired per day, and/or a time range that the pumping system is permitted to operate.

15. The method of claim 12 and further comprising determining the present power consumption based on at least one of a current and/or a voltage provided to the motor.

16. The method of claim 12 and further comprising determining the present power consumption based on at least one of a power factor, a resistance, and/or a friction of the motor.

17. The method of claim 12 and further comprising generating the second motor speed based on the difference value using at least one of integral, proportional, proportional-integral, proportional-derivative, and proportional-integral-derivative control.

18. The method of claim 12 and further comprising generating the second motor speed based on the difference value and an integration constant, wherein the integration constant is dependent on a magnitude of the difference value.

19. The method of claim 18 and further comprising repeating the steps of determining the reference power consumption and driving the motor to reach the steady state condition at the second motor speed at predetermined time intervals.

20. The method of claim 19 and further comprising adjusting the predetermined time intervals based on the integration constant.