Backspin monitor

A system comprising:

• one or more processors;
• and
• at least one computer-readable storage medium having stored therein instructions which, when executed by the one or more processors, cause the one or more processors to:
• access sensor data gathered by one or more sensors that characterizes signals on power input connections of an electric motor configured to drive a subterranean well pump during a forward operation event, the power input connections driving different phases of the electric motor;
• convert the sensor data to waveform data having a bounded range of time generated by a signal buffer, and wherein the range of time correlates to predefined frequencies for computing reference fundamental frequencies and subsequent fundamental frequencies;
• recognize that the electric motor is operating in the forward operation event;
• identify, from the waveform data, reference electrical characteristics of the power input connections from first portions of the signals occurring during the forward operation event, the reference electrical characteristics of the signals are based on reference phase angle differences between the different phases;
• identify, from the waveform data, subsequent electrical characteristics of the power input connections subsequent to the first portions of the signals occurring during an uncharacterized operation event of the electric motor, the subsequent electrical characteristics are based on subsequent phase angle differences between the different phases;
• and
• determine whether the uncharacterized operation event is a backspin event relative to the forward operation event based on a comparison of the subsequent electrical characteristics to the reference electrical characteristics including a comparison of the subsequent fundamental frequencies being less than the reference fundamental frequencies and a threshold frequency, wherein the threshold frequency is less than the reference fundamental frequencies.

A non-transitory computer-readable storage medium comprising at least one instruction for causing a computer or processor to:

• access sensor data gathered by one or more sensors that characterizes signals on power input connections of an electric motor configured to drive a subterranean well pump during a forward operation event, the power input connections driving different phases of the electric motor;
• convert the sensor data to waveform data having a bounded range of time generated by a signal buffer, and wherein the range of time correlates to predefined frequencies for computing reference fundamental frequencies and subsequent fundamental frequencies;
• recognize that the electric motor is operating in the forward operation event;
• identify, from the waveform data, reference electrical characteristics of the power input connections from first portions of the signals occurring during the forward operation event, the reference electrical characteristics of the signals are based on reference phase angle differences between the different phases;
• identify, from the waveform data, subsequent electrical characteristics of the power input connections subsequent to the first portions of the signals occurring during an uncharacterized operation event of the electric motor, the subsequent electrical characteristics are based on subsequent phase angle differences between the different phases;
• and
• determine whether the uncharacterized operation event is a backspin event relative to the forward operation event based on a comparison of the subsequent electrical characteristics to the reference electrical characteristics including a comparison of the subsequent fundamental frequencies being less than the reference fundamental frequencies and a threshold frequency, wherein the threshold frequency is less than the reference fundamental frequencies.