CONTROLLER FOR A MOTOR AND A METHOD OF CONTROLLING THE MOTOR

• US 20090290989A1
• Filed: 07/21/2009
• Published: 11/26/2009
• Est. Priority Date: 04/09/2004
• Status: Active Grant

• Current Assignee: Regal Beloit America, Inc. (Regal Rexnord Corp.)
• Original Assignee: Regal Beloit America, Inc. (Regal Rexnord Corp.)
• Inventors: Mehlhorn, William Louis, Phillips, Andrew William
• Granted Patent: US 8,353,678 B2
• Time in Patent Office: Days
• US Class Current: 417/44.1
• CPC Class Codes: F04D 15/0066 by changing the speed, e.g. of the driving engine
• 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 method of controlling a motor operating a pumping apparatus of a fluid-pumping application. The pumping apparatus includes a pump having an inlet to receive a fluid and an outlet to exhaust the fluid, and the motor coupled to the pump to operate the pump. The method includes the acts of controlling the motor to operate the pump and monitoring the operation of the pump. The monitoring act includes monitoring a power of the motor, and determining whether the monitored power indicates an undesired flow of fluid through the pump. The method further includes the act of controlling the motor to cease operation of the pump when the determination indicates an undesired flow of fluid through the pump and zero or more other conditions exist.

Claims

1. A method of controlling a motor operating a pumping apparatus of a fluid-pumping application, the pumping apparatus comprising

a pump having an inlet to receive a fluid and an outlet to exhaust the fluid, and

the motor coupled to the pump to operate the pump, the method comprising:

controlling the motor to operate the pump;

monitoring the operation of the pump, the monitoring act comprising

monitoring a power of the motor, and

determining whether the monitored power indicates a condition of the pump; and

controlling the motor to operate the pump based on the condition of the pump and zero or more other conditions.

2. A method as set forth in claim 1 wherein the condition of the pump is an undesired flow of fluid through the pump.

3. A method as set forth in claim 1 wherein the condition of the pump is a desired flow of fluid through the pump.

4. A method as set forth in claim 1 wherein the act of monitoring a power comprises sensing a motor voltage, sensing a motor current, and determining a power of the motor based on the sensed motor voltage and the sensed motor current.

5. A method as set forth in claim 4 wherein the pumping apparatus further comprises a voltage sensor and a current sensor coupled to the motor, wherein sensing a motor voltage comprises sensing a voltage applied to the motor with the voltage sensor, and wherein sensing a motor current comprises sensing a current through the motor with the current sensor.

6. A method as set forth in claim 1 wherein the act of monitoring a power comprises sensing a voltage applied to the motor, determining an averaged motor voltage based on the sensed voltage, sensing a current through the motor, determining an averaged motor current based on the sensed current, determining a power factor for the motor based on the sensed voltage and the sensed current, and determining the motor power with the averaged motor voltage, the averaged motor current, and the motor power factor.

7. A method as set forth in claim 6 wherein the act of determining a power factor for the motor comprises sensing a first zero-crossing of the sensed voltage, sensing a second zero-crossing of the sensed current, and determining the power factor for the motor based on the sensed zero-crossings.

8. A method as set forth in claim 1 wherein the determining act comprises determining whether the monitored power indicates a low fluid inlet flow, and wherein the act of controlling the motor to operate the pump comprises controlling the motor to cease operation of the pump when the determination indicates a low fluid inlet flow and zero or more other conditions exist.

9. A method as set forth in claim 1 wherein the determining act comprises determining whether the monitored power indicates a high fluid outlet flow, and wherein the act of controlling the motor to operate the pump comprises controlling the motor to cease operation of the pump when the determination indicates a high fluid outlet flow and zero or more other conditions exist.

10. A method as set forth in claim 1 wherein the method further comprises calibrating the motor to obtain a power calibration value, and wherein the determining act comprises determining whether the monitored power is within a window of the power calibration value, the window indicative of a desired flow of fluid through the pump.

11. A method as set forth in claim 1 wherein the method further comprises calibrating the motor to obtain a power calibration value, and wherein the determining act comprises determining whether the monitored power is not within a window of the power calibration value, the window indicative of a desired flow of fluid through the pump.

12. A method as set forth in claim 11 wherein the act of calibrating the motor comprises initiating a calibration event, determining a power of the motor in response to initiating the calibration event, and setting the power calibration value to the determined power.

13. A method as set forth in claim 1 wherein the determining act comprises determining whether the monitored power is less than a threshold indicative of a low fluid inlet flow.

14. A method as set forth in claim 1 wherein the determining act comprises determining whether the monitored power is greater than a threshold indicative of a high fluid outlet flow.

15. A method as set forth in claim 1 wherein the method further comprises monitoring a pump inlet side pressure, determining whether the monitored pressure indicates a low fluid inlet flow, and controlling the motor to cease operation of the pump when the determination indicates a low fluid inlet flow and zero or more other conditions exist.

16. A method as set forth in claim 1 wherein the zero or more other conditions consists of zero conditions.

17. A method as set forth in claim 1 wherein the method further comprises indicating a normal operation state for the pumping apparatus, and wherein the act of controlling the motor to operate the pump comprises controlling the motor to cease operation of the pump when the determination indicates an undesired flow, the pumping apparatus is in a normal operation state, and zero or more other conditions exist.

18. A method as set forth in claim 1 wherein the act of controlling the motor to operate the pump comprises initiating operation of the motor to prime the pump, wherein the method further comprises indicating a lockout state when initiating operation of the motor to prime the pump, and ceasing the lockout state, and wherein the act of controlling the motor to operate the pump comprises controlling the motor to cease operation of the pump when the determination indicates an undesired flow, the pumping apparatus is in a normal operation state, and zero or more other conditions exist.

19. A method as set forth in claim 18 wherein the lockout state lasts a time period.

20. A method as set forth in claim 18 wherein the method comprises calibrating the motor to obtain a power calibration value, wherein ceasing the lockout state comprises monitoring a power of the motor and determining whether the monitored power is within a window of the power calibration value for a time period, the window indicative of a desired flow of fluid through the pump.

21. A method as set forth in claim 18 wherein ceasing the lockout state comprises monitoring a power of the motor pump and determining whether the monitored power is greater than a threshold for a time period.

22. A method as set forth in claim 21 wherein the time period is an instantaneous time period.