Technique to detect motor leakage flux anomalies

1. An apparatus to detect a motor leakage flux anomaly, the apparatus comprising:

a motor comprising an outer frame and a winding, wherein the motor is configured to drive a pump;

a sensor attached to the outer frame, wherein the sensor configured to

sense a sinusoidal waveform of magnetic flux caused by current that flows in the winding of the motor; and

a signal processor configured to:

receive a signal from the sensor that contains information about the sensed sinusoidal waveform, wherein the sinusoidal waveform has a component of distortion caused at least in part by the magnetic flux created by the current that flows in the winding of the motor;

receive another signal that contains information about a pure sinusoidal waveform of a fundamental frequency of the sinusoidal waveform;

compare the signal and the other signal;

extract a non-sinusoidal magnetic flux waveform of magnetic flux distortion based on the comparison;

compare the extracted non-sinusoidal magnetic flux waveform of magnetic flux distortion to a baseline non-sinusoidal magnetic flux waveform signature of the motor recorded during a period of proper operation; and

generate a corresponding signal that contains information about anomalies in the motor based on the comparison of the extracted non-sinusoidal magnetic flux waveform of magnetic flux distortion to the baseline non-sinusoidal magnetic flux waveform signature.

2. The apparatus of claim 1 , wherein the sensor is a motor magnetic flux sensor arranged in relation to the winding.

3. The apparatus of claim 2 , wherein the sensor is a leakage magnetic flux sensor.

4. The apparatus of claim 1 , wherein the signal processor is configured to extract the non-sinusoidal magnetic flux waveform of magnetic flux distortion through subtraction of the pure sinusoidal waveform from the sinusoidal waveform of magnetic flux distortion.

5. The apparatus of claim 1 , wherein the signal processor is further configured to determine information about either a mechanical or an electrical pending failure of a component of the motor based on the magnetic flux distortion.

6. The apparatus of claim 5 , wherein the mechanical failure includes vibration caused by a misalignment, an out of balance condition, or one or more failing bearings, and the electrical failure includes a partially shorted winding, a broken rotor bar, an eccentric air gap, or damaged laminations.

7. The apparatus of claim 5 , wherein the signal processor is configured to determine the mechanical or the electrical pending failure of a component of the motor, through one or more of:

amplification of the non-sinusoidal magnetic flux waveform of magnetic flux distortion though a dynamically boosted gain for further analysis;

analysis of the baseline non sinusoidal flux waveform signature and the non-sinusoidal magnetic flux waveform of magnetic flux distortion to determine one or more minimum deviations of amplitude and frequency of the baseline non-sinusoidal flux waveform signature over time; or

establishment of an alarm threshold for a deviation value that indicates an abnormal condition or a potential abnormal condition.

8. The apparatus of claim 1 , wherein the signal processor is configured to perform a spectral analysis on the non-sinusoidal magnetic flux waveform of magnetic flux distortion to determine the anomalies.

9. The apparatus of claim 1 , wherein the motor is an AC induction motor configured to draw a pure sinusoid waveform of current when supplied with a sinusoid AC voltage.

10. The apparatus of claim 1 , wherein the signal processor is further configured to provide the corresponding signal that contains information about the anomalies in the motor as a control signal.

11. The apparatus of claim 10 , wherein the provided corresponding signal contains information about one or more of a vibration caused by the misalignment, an out of balance condition, one or more failing bearings, a partially shorted winding, a broken rotor bar, an eccentric air gap, or damaged laminations.

12. A method to detect a motor leakage anomaly, the method comprising:

sensing, by a sensor, a sinusoidal waveform of magnetic flux caused by a current flowing in a winding of a motor that drives a pump, wherein the sinusoidal waveform of magnetic flux has a component of distortion caused at least in part by a magnetic flux created by the current flowing;

receiving, by a signal processor, a first signal from the sensor, wherein the first signal contains information about the sensed sinusoidal waveform of magnetic flux;

receiving, by the signal processor, a second signal, wherein the second signal contains information about a pure sinusoidal waveform of a sensed fundamental frequency of the magnetic flux;

comparing the first signal and the second signal;

extracting a non-sinusoidal magnetic flux waveform of magnetic flux distortion based on the comparison;

comparing the extracted non-sinusoidal magnetic flux waveform of magnetic flux distortion to a baseline non-sinusoidal magnetic flux waveform signature of the motor; and

generating, by the signal processor, a corresponding signal that contains information about anomalies in the motor based upon the comparison of the extracted non-sinusoidal magnetic flux waveform of magnetic flux distortion to a baseline non-sinusoidal magnetic flux waveform signature of the motor.

13. A pump motor anomaly detection system, the system comprising:

a pump;

a motor comprising an outer frame and a winding, wherein the motor is configured to drive the pump;

a sensor attached to the outer frame, wherein the sensor is configured to sense sinusoidal waveform of magnetic flux caused by a current that flows in the winding of the motor;

a memory configured to store a baseline non-sinusoidal magnetic flux waveform signature of the motor recorded during a period of proper operation; and

a controller configured to:

receive a first signal from the sensor that contains information about the sensed sinusoidal waveform of magnetic flux, wherein the sinusoidal waveform of magnetic flux has a component of distortion caused at least in part by the magnetic flux created by the current;

receive a second signal that contains information about a pure sinusoidal waveform of a fundamental frequency of the magnetic flux;

compare the first signal and the second signal;

extract a non-sinusoidal magnetic flux waveform of magnetic flux distortion based on the comparison;

compare the extracted non-sinusoidal magnetic flux waveform of magnetic flux distortion to the stored baseline non-sinusoidal magnetic flux waveform signature of the motor; and

generate a signal that contains information about an anomaly in the motor based on the comparison of the extracted non-sinusoidal magnetic flux waveform of magnetic flux distortion to the stored baseline non-sinusoidal magnetic flux waveform signature of the motor.

14. The system of claim 13 , wherein the sensor is a leakage magnetic flux sensor or a current sensor.

15. The system of claim 13 , wherein the controller is further configured to determine one or more of a vibration caused by a misalignment, an out of balance condition, one or more failing bearings, a partially shorted winding, a broken rotor bar, an eccentric air gap, or damaged laminations based on the comparison of the extracted non-sinusoidal magnetic flux waveform of magnetic flux distortion to the stored baseline non-sinusoidal magnetic flux waveform signature of the motor.

16. The system of claim 13 , wherein the second signal is sensed from a supply voltage of the motor.

17. The system of claim 13 , wherein the controller is further configured to perform one or more of an amplification or a spectral analysis of the extracted non-sinusoidal magnetic flux waveform of the magnetic flux distortion.

18. The system of claim 13 , wherein the anomaly in the motor is an abnormal condition to cause immediate damage or a potential abnormal condition not to cause immediate damage.