Technique to detect motor leakage flux anomalies

1. An apparatus to detect a motor leakage flux anomaly from a winding of a motor in a frame, the apparatus comprising:

a sensor attached to the frame of the motor, wherein the sensor is configured to sense a sinusoidal waveform of magnetic flux caused by a 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 to the other signal;

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

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;

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;

determine a minimum deviation of the non-sinusoidal magnetic flux waveform of the magnetic flux distortion over time;

compare the minimum deviation to a pre-established alarm threshold associated with the pending failure; and

include a result of the comparison of the minimum deviation to a pre-established alarm threshold in the corresponding signal.

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. A system to detect a pending failure of a component of a motor, the system comprising:

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

a controller coupled to the flux detector, the controller comprising:

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 signal processor configured to:

receive a signal from the flux detector 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;

decompose the received signal to determine the sensed sinusoidal waveform of the magnetic flux caused by the current and a non-sinusoidal magnetic flux waveform of the distortion caused at least in part by the magnetic flux created by the current;

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

generate a corresponding signal that contains information about the pending failure of the component of the motor based on the comparison of the non-sinusoidal magnetic flux waveform of the distortion to the baseline non-sinusoidal magnetic flux waveform signature stored in the memory;

determine a minimum deviation of the non-sinusoidal magnetic flux waveform of the distortion over time;

compare the minimum deviation to a pre-established alarm threshold associated with the pending failure; and

include a result of the comparison of the minimum deviation to a pre-established alarm threshold in the corresponding signal.

8. The system of claim 7 , wherein the signal processor is further configured to:

determine a pure sinusoidal waveform of a fundamental frequency of the sinusoidal waveform;

compare the signal to the pure sinusoidal waveform; and

extract the non-sinusoidal magnetic flux waveform of the distortion based on the comparison of the signal to the pure sinusoidal waveform.

9. The system of claim 8 , wherein the signal processor is configured to determine the pure sinusoidal waveform of a fundamental frequency of the sinusoidal waveform by sensing the sinusoidal waveform from a supply voltage of the motor.

10. The system of claim 7 , wherein the signal processor is further configured to:

receive another signal from the flux detector during the period of proper operation;

extract the non-sinusoidal magnetic flux waveform from the other signal; and

store the extracted non-sinusoidal magnetic flux waveform as the baseline non-sinusoidal magnetic flux waveform signature of the motor.

11. The system of claim 7 , wherein the flux detector is a leakage magnetic flux sensor or a current sensor.

12. The system of claim 7 , wherein the signal processor is further configured to determine the pending failure as 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.

13. The system of claim 7 , wherein the signal processor is further configured to perform one or more of an amplification or a spectral analysis of the non-sinusoidal magnetic flux waveform of the distortion.

14. The system of claim 7 , wherein the pending failure is an abnormal condition to cause immediate damage or a potential abnormal condition not to cause immediate damage.

15. The system of claim 7 , wherein the minimum deviation is a amplitude deviation or a frequency deviation.

16. A method to detect a pending failure of a component of a motor that drives a pump, the method comprising:

sensing, by a flux detector attached to a frame of the motor in relation to a winding of the motor, a sinusoidal waveform of magnetic flux caused by a current that flows in the winding of the motor;

receiving, by a signal processor, a signal from the flux detector 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;

decomposing, by the signal processor, the received signal to determine the sensed sinusoidal waveform of the magnetic flux caused by the current and a non-sinusoidal magnetic flux waveform of the distortion caused at least in part by the magnetic flux created by the current;

comparing, by the signal processor, the non-sinusoidal magnetic flux waveform of the distortion to a baseline non-sinusoidal magnetic flux waveform signature of the motor stored in a memory;

generating, by the signal processor, a corresponding signal that contains information about the pending failure of the component of the motor based on the comparison of the non-sinusoidal magnetic flux waveform of the distortion to the baseline non-sinusoidal magnetic flux waveform signature stored in the memory;

determining a minimum deviation of the non-sinusoidal magnetic flux waveform of the distortion over time;

comparing the minimum deviation to a pre-established alarm threshold associated with the pending failure; and

including a result of the comparison of the minimum deviation to a pre-established alarm threshold in the corresponding signal.

17. The method of claim 16 , further comprising:

determining, by the signal processor, a pure sinusoidal waveform of a fundamental frequency of the sinusoidal waveform by sensing the sinusoidal waveform from a supply voltage of the motor;

comparing, by the signal processor, the signal to the pure sinusoidal waveform; and

extracting, by the signal processor, the non-sinusoidal magnetic flux waveform of the distortion based on the comparison of the signal to the pure sinusoidal waveform.

18. The method of claim 16 , further comprising:

receiving, by the signal processor, another signal from the flux detector during the period of proper operation;

extracting, by the signal processor, the non-sinusoidal magnetic flux waveform from the other signal; and

storing, by the signal processor, the extracted non-sinusoidal magnetic flux waveform as the baseline non-sinusoidal magnetic flux waveform signature of the motor.

19. The method of claim 16 , further comprising:

determining, by the signal processor, the pending failure as an abnormal condition to cause immediate damage or as a potential abnormal condition not to cause immediate damage.