Method and apparatus for pump control using varying equivalent system characteristic curve, AKA an adaptive control curve

• US 8,700,221 B2
• Filed: 12/30/2010
• Issued: 04/15/2014
• Est. Priority Date: 12/30/2010
• Status: Active Grant

• Current Assignee: Fluid Handling LLC (Xylem, Inc.)
• Original Assignee: Fluid Handling LLC (Xylem, Inc.)
• Inventors: Cheng, Andrew A., Gu, James J.
• Primary Examiner(s): Ali, Mohammad
• Assistant Examiner(s): WHITTINGTON, ANTHONY T
• Application Number:
  US12/982,286
• Publication Number:
  US 20120173027A1
• Time in Patent Office: 1,202 Days
• Field of Search: 700/282, 370/241, 165/157
• US Class Current: 700/282
• CPC Class Codes: F04D 15/0066 by changing the speed, e.g. of the driving engine
• CPC Class Codes: F04D 15/0088 Testing machines

Abstract

The present invention provides, e.g., apparatus comprising at least one processor; at least one memory including computer program code; the at least one memory and computer program code being configured, with at least one processor, to cause the apparatus at least to: respond to signaling containing information about an instant pressure and a flow rate of fluid being pumped in a pumping system, and obtain an adaptive control curve based at least partly on the instant pressure and flow rate using an adaptive moving average filter. The adaptive moving average filter may be based at least partly on a system flow equation:
SAMA_t=AMAF(Q_t/√{square root over (ΔP_t)}),
where the function AMAF is an adaptive moving average filter (AMAF), and the parameters Q and ΔP are a system flow rate and differential pressure respectively. The at least one memory and computer program code may be configured to, with the at least one processor, to cause the apparatus at least to obtain an optimal control pressure set point from the adaptive control curve with respect to an instant flow rate or a moving average flow rate as
SP_t=MA(Q_t)/SAMA_t,
where the function MA is a moving average filter (MA), to obtain a desired pump speed through a PID control.

Claims

1. Apparatus comprising:

at least one processor;

at least one memory including computer program code;

the at least one non-transitory tangible computer readable storage medium or memory and computer program code configured, with at least one processor, to cause the apparatus at least to;

respond to signaling containing information about an instant pressure and a flow rate of fluid being pumped in a pumping system,

obtain an adaptive control curve based at least partly on the instant pressure and flow rate using an adaptive moving average filter,

set up a control set point for a system process variable from the adaptive control curve to obtain a desired pump speed through a pump control or controller, including a PID control, and

determine a pump motor drive speed signal based at least partly on the control set point for the system process variable from the adaptive control curve.

2. Apparatus according to claim 1, where the adaptive control curve, SAMA_t, is based at least partly on a system flow equation:

SAMA_t=AMAF(Q_t/√

{square root over (Δ

P_t)}),

where the function AMAF is an adaptive moving average filter (AMAF), and the parameters Q and Δ

P are a system flow rate and differential pressure respectively.

3. Apparatus according to claim 2, wherein the at least one memory and computer program code are configured, with the at least one processor, to cause the apparatus at least to obtain an optimal control pressure set point from the adaptive control curve with respect to an instant flow rate or a moving average flow rate as

SP_t=MA(Q_t)/SAMA_t,

where the function MA is a moving average filter (MA).

4. Apparatus according to claim 1, wherein the adaptive moving average filter includes using a moving average filter function (MA), or an adaptive moving average filter function to obtain the adaptive control curve, respectively.

5. Apparatus according to claim 1, wherein the at least one non-transitory tangible computer readable storage medium or memory and computer program code are configured, with the at least one processor, to cause the apparatus at least to obtain pump speed using the pump control or controller, including the PID control, with the instant system pressure versus the set point obtained from the adaptive control curve.

6. Apparatus according to claim 1, wherein the at least one non-transitory tangible computer readable storage medium or memory and computer program code are configured, with the at least one processor, to cause the apparatus at least to include a threshold at beginning of the adaptive control curve for accommodating a pump initial speed.

7. Apparatus according to claim 1, wherein the apparatus forms part of the pump control or controller, including the PID controller, and including for use in a heating and cooling water system.

8. Apparatus according to claim 1, wherein the apparatus forms part of a primary control system or a secondary control system.

9. Apparatus according to claim 1, wherein the signaling for obtaining the adaptive control curve includes input processing control signals containing information about system or zone pressures or differential pressures together with system or zone flow rates, or other derivative signals, including as power or torsion.

20. Apparatus according to claim 1, wherein the apparatus further comprises:

either at least one input processor configured to receive process variable signals, including the signaling containing information about the instant pressure and the flow rate of fluid being pumped in the pumping system;

or

at least one output processor configured to provide the pump motor drive speed signal;

or

a combination thereof.

10. A method comprising:

implementing steps with apparatus comprising at least one processor and at least one non-transitory tangible computer readable storage medium or memory including computer program code, as follows;

responding to signaling containing information about an instant pressure and a flow rate of fluid being pumped in a pumping system;

obtaining an adaptive control curve based at least partly on the instant pressure and flow rate using an adaptive moving average filter;

setting up a control set point for a system process variable from the adaptive control curve to obtain a desired pump speed through a pump control or controller, including a PID control; and

determining a pump motor drive speed signal based at least partly on the control set point for the system process variable from the adaptive control curve.

11. A method according to claim 10, where the adaptive control curve is based at least partly on a system flow equation:

SAMA_t=AMAF(Q_t/√

{square root over (Δ

P_t)}),

where the function AMAF is an adaptive moving average filter function (AMAF), and the parameters Q and Δ

P are a system flow rate and differential pressure respectively.

12. A method according to claim 11, where the at least one non-transitory tangible computer readable storage medium or memory and computer program code are configured to, with the at least one processor, to cause the apparatus at least to obtain an optimal control pressure set point from the adaptive control curve with respect to an instant flow rate or a moving average flow rate as

SP_t=MA(Q_t)/SAMA_t,

where the function MA is a moving average filter function (MA).

13. A method according to claim 10, wherein the adaptive moving average filter includes using a moving average filter function (MA), or an adaptive moving average filter function to obtain the adaptive control curve, respectively.

14. A method according to claim 10, wherein the at least one non-transitory tangible computer readable storage medium or memory and computer program code are configured, with the at least one processor, to cause the apparatus at least to obtain pump speed using the pump control or controller, including the PID control, with the instant system pressure versus the set point obtained from the adaptive control curve.

15. A method according to claim 10, wherein the at least one non-transitory tangible computer readable storage medium or memory and computer program code are configured, with the at least one processor, to cause the apparatus at least to include a threshold at beginning of the adaptive control curve for accommodating a pump initial speed.

16. A method according to claim 10, wherein the apparatus forms part of the pump control or controller, including the PID controller, and including for use in a heating and cooling water system.

17. A method according to claim 10, wherein the apparatus forms part of a primary control system or a secondary control system.

18. A method according to claim 10, wherein the signaling for obtaining the adaptive control curve may include input processing control signals containing information about system or zone pressures or differential pressures together with system or zone flow rates, or other derivative signals, including as power or torsion.

21. A method according to claim 10, wherein the method further comprises:

either receiving in at least one input processor process variable signals, including the signaling containing information about the instant pressure and the flow rate of fluid being pumped in the pumping system;

or

providing with at least one output processor the pump motor drive speed signal;

or

a combination thereof.

19. Apparatus, including a system having a pump controller, the pump controller comprising:

at least one processor;

at least one non-transitory tangible computer readable storage medium or memory and computer program code configured, with at least one processor, to cause the pump controller at least to;

respond to signaling containing information about an instant pressure and a flow rate of fluid being pumped by a pump in a pumping system,

obtain an adaptive control curve based at least partly on the instant pressure and flow rate using an adaptive moving average filter,

set up a control set point for a system process variable from the adaptive control curve to obtain a desired pump speed through the pump control or controller, including a PID control, and

determine a pump motor drive speed signal based at least partly on the control set point for the system process variable from the adaptive control curve.

22. Apparatus according to claim 19, wherein the apparatus further comprises:

either at least one input processor configured to receive process variable signals, including the signaling containing information about the instant pressure and the flow rate of fluid being pumped in the pumping system;

or

at least one output processor configured to provide the pump motor drive speed signal to the pump;

or

a combination thereof.