Electrical motor monitoring system and method

• US 6,262,550 B1
• Filed: 12/17/1999
• Issued: 07/17/2001
• Est. Priority Date: 12/17/1999
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Premerlani, William J., Koegl, Rudolph A., Krahn, John R., Kliman, Gerald B.
• Primary Examiner(s): Nappi, Robert E.
• Assistant Examiner(s): Leykin, Rita
• Application Number:
  US09/465,935
• Time in Patent Office: 578 Days
• Field of Search: 318/565, 388/909
• US Class Current: 318/565
• CPC Class Codes: G01R 31/343 in operation
• CPC Class Codes: G05B 2223/06 Remote monitoring
• CPC Class Codes: G05B 23/0264 Control of logging system, e.g. decision on which data to store; time-stamping measurements
• CPC Class Codes: Y10S 388/909 Monitoring means

Abstract

An integrated motor monitoring system collects, analyzes, and stores to database(s) on-line and off-line coordinated real-time motor data for industrial AC and DC motors. On-line coordinated real-time motor data from both on-motor sensors and remote sensors at a motor control center are collected simultaneously and processed. Off-line measurements are performed with integrated stimulus and measurement apparatus. Monitoring units at the motor and motor control center each collect specific data on the motor. The database provides current and historical data on the motor for analyses conducted at the motor or at the motor control center. Additionally the motor monitoring system has the capability of relating motor system or process events with motor performance.

Claims

1. A motor monitoring system comprising:

an on-site motor instrument unit having an on-site motor sensor for monitoring a motor, wherein the on-site sensor generates a signal representative of a first motor condition;

an on-site motor computer unit electronically connectable to the on-site motor measurement unit, and processing the signal representative of the first motor condition;

an off-site motor control center having a remote sensor for remotely monitoring a second motor condition, wherein the remote sensor generates a signal representative of a second motor condition;

an off-site motor control center computer unit electronically connectable to the off-site motor control center and processing the signals representative of the second motor condition; and

a communications link between the on-site motor computer unit and the off-site computer;

wherein at least one of the on-site motor computer and the off-site motor control center computer synchronize information representative of the second motor condition with information representative of the first motor condition.

2. A motor monitoring system as in claim 1 wherein the second motor condition includes at least one condition from a group of conditions consisting of electrical power drawn by the motor, voltages drawn by the motor, currents drawn by the motor, and leakage current.

3. A motor monitoring system as in claim 1 wherein the communications link includes synchronization information to synchronize the information representing the first motor condition and the second motor condition.

4. A motor monitoring system as in claim 1 wherein the first motor condition includes at least one condition of a group of conditions consisting of motor speed, vibration, temperature, sound, radio frequency (RF) emissions, commutator profile, rotor position and magnetic stray flux.

7. A motor monitoring system as in claim 1 wherein the second motor condition includes a waveform of current or voltage powering the motor.

8. A motor monitoring system as in claim 1 further comprising a database accessible to at least one of said on-site motor computer unit and said off-site motor control center computer unit having synchronized data representing the first motor condition and the second motor condition.

5. A motor monitoring system comprising:

an on-site motor instrument unit having an on-site motor sensor for monitoring a motor, wherein the on-site sensor generates a signal representative of a first motor condition;

an on-site motor computer unit electronically connectable to the on-site motor measurement unit, and processing the signal representative of the first motor condition;

an off-site motor control center having a remote sensor for remotely monitoring a second motor condition, wherein the remote sensor generates a signal representative of a second motor condition;

an off-site motor control center computer unit electronically connectable to the off-site motor control center and processing the signals representative of the second motor condition;

a communications link between the on-site motor computer unit and the off-site computer; and

a third motor condition, which is monitored when the motor is off-line, and data regarding the third motor condition is stored a database.

6. A motor monitoring system comprising:

an on-site motor instrument unit having an on-site motor sensor for monitoring a motor, wherein the on-site sensor generates a signal representative of a first motor condition;

an on-site motor computer unit electronically connectable to the on-site motor measurement unit, and processing the signal representative of the first motor condition;

an off-site motor control center having a remote sensor for remotely monitoring a second motor condition, wherein the remote sensor generates a signal representative of a second motor condition;

an off-site motor control center computer unit electronically connectable to the off-site motor control center and processing the signals representative of the second motor condition; and

a communications link between the on-site motor computer unit and the off-site computer, wherein the communications link is an Ethernet network in communication with the off-site motor control center computer unit and the on-site motor computer unit.

9. A method for monitoring a motor using an on-site motor instrument unit having an on-site motor sensor, an on-site motor computer unit electronically connectable to the on-site motor measurement unit, an off-site motor control center having an off-site sensor, an off-site motor control center computer unit electronically connectable to the off-site motor control center, and a communication link between the on-site motor computer unit and the off-site computer, wherein the method comprises the steps of:

a. the on-site sensor monitoring a first motor condition at the motor and providing data on the first motor condition to the on-site motor computer unit;

b. the on-site sensor monitoring a second motor condition remotely from the motor and providing data on the second motor condition to the off-site motor control center computer unit;

c. transmitting the data on at least one of the first motor condition and the second motor condition to at least one of the on-site motor computer unit and the off-site motor control center computer unit;

d. synchronizing the data on the first motor condition with the data on the second motor condition.

10. A method for monitoring a motor as in claim 9 wherein in step (c) the data on the first motor condition and the second motor condition are exchanged over the communication link.

11. A method for monitoring a motor as in claim 9 further comprising the step of comparatively displaying the synchronized data on the first motor condition and on the second motor condition.

12. A method for monitoring a motor as in claim 11 wherein the synchronized data is displayed by at least one of the on-site motor computer unit and the off-site motor control computer unit.

13. A method for monitoring a motor as in claim 9 wherein the second condition is at least one condition from a group of conditions consisting of electrical power drawn by the motor, voltages drawn by the motor, currents drawn by the motor, and leakage current.

15. A method for monitoring a motor as in claim 9 further comprising the steps of monitoring a third motor condition occurring when the motor is off-line and storing data regarding the first, second and third motor conditions in a database.

14. A method for monitoring a motor using an on-site motor instrument unit having an on-site motor sensor, an on-site motor computer unit electronically connectable to the on-site motor measurement unit, an off-site motor control center having an off-site sensor, an off-site motor control center computer unit electronically connectable to the off-site motor control center, and a communication link between the on-site motor computer unit and the off-site computer, wherein the method comprises the steps of:

a. the on-site sensor monitoring a first motor condition at the motor and providing data on the first motor condition to the on-site motor computer unit;

b. the on-site sensor monitoring a second motor condition remotely from the motor and providing data on the second motor condition to the off-site motor control center computer unit;

c. transmitting the data on at least one of the first motor condition and the second motor condition to at least one of the on-site motor computer unit and the off-site motor control center computer unit, wherein the data on the first motor condition and the second motor condition are captured in response to a predetermined external event;

d. synchronizing the data on the first motor condition with the data on the second motor condition.

16. A motor monitoring system comprising:

a motor at a motor site;

an on-site motor measurement unit having an on-site motor sensors mounted proximate to the motor, wherein the on-site sensor generates a signal representative of a first motor condition;

an on-site motor computer unit electronically connected to the on-site motor measurement unit, and processing the signal generated by the on-site motor sensor, wherein the on-site motor computer unit stores data in a database representative of the signal generated by the on-site motor sensor;

an off-site motor control center having a remote sensor measuring motor performance from a location remote from the motor site, wherein the remote sensor generates a signal representative of a second motor condition;

an off-site motor control center computer unit electronically connected to the off-site motor control center and processing the signal representative of the second motor condition, wherein the off-site motor control center computer unit stores data in the database that is representative of the signals generated by the sensor at the off-site motor control center;

wherein the on-site motor computer unit and the off-site motor control center computer unit synchronize the signal representative of a second motor condition with the signal representative of the first motor condition.

17. A method for determining torque in a rotating electrical motor having a dynamic electrical sensor comprising the steps of:

a. sensing with the electrical sensor an alternating current waveform and an alternating voltage waveform being applied to drive the motor;

b. generating a voltage phasor based on a signal generated by the sensor in step (a);

c. determining a flux linkage phasor based on the voltage phasor and a frequency of the alternating voltage;

d. generating an alternating flux linkage waveform based on a flux linkage phasor generated in step (c);

e. determining dynamic torque from a cross-product of the alternating flux linkage waveform and alternating current waveform.

18. A method as in claim 17 further comprising determining the average torque from the dynamic torque.