Flow control

• US 8,801,389 B2
• Filed: 12/01/2010
• Issued: 08/12/2014
• 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: Danfoss Low Power Drives, Pentair Water Pool And Spa Incorporated (Pentair Plc (Ireland))
• Inventors: Stiles, Robert W. Jr., Berthelsen, Lars Hoffmann, Westermann-Rasmussen, Peter, Kjaer, Gert, Lungeanu, Florin
• Primary Examiner(s): Freay, Charles
• Assistant Examiner(s): COMLEY, ALEXANDER BRYANT
• Application Number:
  US12/958,228
• Publication Number:
  US 20110076156A1
• Time in Patent Office: 1,350 Days
• Field of Search: 417/42, 417/43, 417/44.1, 417/20, 417/22
• US Class Current: 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

Embodiments of the invention provide a pumping system for at least one aquatic application. The pumping system includes a pump, a motor coupled to the pump, and a controller in communication with the motor. The controller determines a first motor speed, obtains a reference flow rate, determines a present flow rate, and determines a present power consumption. The controller calculates a difference value between the reference flow rate and the present flow rate, and uses at least one of integral, proportional, and derivative control to generate a second motor speed based on the difference value. The controller attempts to drive the motor at the second motor speed until reaching a steady state condition.

Claims

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

a pump;

a motor coupled to the pump; and

a controller in communication with the motor, the controller determining a first motor speed, the controller obtaining a reference flow rate, the controller determining a present flow rate, the controller accessing curves of speed versus flow rate for discrete power consumptions to determine the present flow rate, the controller determining a present power consumption, the controller calculating a difference value between the reference flow rate and the present flow rate, the controller using at least one of integral, proportional, and derivative control to generate a second motor speed based on the difference value, and the controller attempting to drive the motor at the second motor speed until reaching a steady state condition.

2. The pumping system of claim 1, wherein the first motor speed is determined from a present shaft speed of a synchronous motor.

3. The pumping system of claim 1, wherein the reference flow rate is calculated based on at least one of a volume of the at least one aquatic application, a number of turnovers desired per day, and a time range that the pumping system is permitted to operate.

4. The pumping system of claim 1, wherein the present power consumption is based on at least one of current and voltage provided to the motor.

5. The pumping system of claim 1, wherein the present power consumption is based on at least one of a power factor, resistance, and friction of the motor.

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

a pump;

a motor coupled to the pump; and

a controller in communication with the motor,

the controller determining a first motor speed,

the controller obtaining a reference flow rate,

the controller determining a present power consumption,

the controller determining a present flow rate, wherein a flow estimator uses curves of speed versus flow rate for discrete power consumptions to determine the present flow rate,

the controller calculating a difference value between the reference flow rate and the present flow rate,

the controller using at least one of integral, proportional, and derivative control to generate a second motor speed based on the difference value, and

the controller attempting to drive the motor at the second motor speed until reaching a steady state condition.

7. The pumping system of claim 6, wherein the first motor speed is determined from a present shaft speed of a synchronous motor.

8. The pumping system of claim 6, wherein the reference flow rate is calculated based on at least one of a volume of the at least one aquatic application, a number of turnovers desired per day, and a time range that the pumping system is permitted to operate.

9. The pumping system of claim 6, wherein the present power consumption is based on at least one of current and voltage provided to the motor.

10. The pumping system of claim 6, wherein the present power consumption is based on at least one of a power factor, resistance, and friction of the motor.

11. A method of controlling a pumping system, the method comprising:

providing a motor coupled to a pump;

providing a controller in communication with the motor;

determining a first motor speed value;

determining a present power consumption value;

obtaining a reference flow rate value;

determining a present flow rate value using curves of speed versus flow rate for discrete power consumptions;

generating a difference value between the reference flow rate and the present flow rate; and

driving the motor at a second motor speed based on the difference value until reaching a steady state condition.

12. The method of claim 11, wherein the first motor speed is determined directly from a sensor reading a present shaft speed.

13. The method of claim 11, wherein the first motor speed is determined from a present shaft speed of a synchronous motor.

14. The method of claim 11, wherein the reference flow rate is calculated based on at least one of a volume of the at least one aquatic application, a number of turnovers desired per day, and a time range that the pumping system is permitted to operate.

15. The method of claim 11, wherein the present power consumption is based on at least one of current and voltage provided to the motor.

16. The method of claim 11, wherein the present power consumption is based on at least one of a power factor, resistance, and friction of the motor.