Abstract: Systems, methods, and apparatus, including computer programs encoded on computer-readable media, for monitoring an electromotive force (EMF) for an electrical submersible pump (ESP) having a permanent magnet motor (PMM) are disclosed. One or more voltages and one or more currents may be monitored in a cable coupled to the ESP having the PMM and being used in a well system. It may be determined whether at least one of the one or more voltages in the cable exceeds a voltage threshold and whether at least one of the one or more currents in the cable exceeds a current threshold. A notification may be generated to indicate an EMF condition if at least one of the one or more voltages and the one or more currents in the cable exceeds at least one of the one or more thresholds.

Abstract: Safety control apparatus for limiting voltages on electrical conductors included in a motor power cable that are connected to a motor of an electrical submersible pump assembly are described. The safety control apparatus include circuitry, which when electrically coupled to the electrical conductors of the motor power cable, is configured to controllably connect and disconnect the electrical conductors to and from, respectively, a motor load element, to provide a braking function limiting the motor rotational speed, and thereby limit the voltage level that the rotation of the motor may induce onto the electrical conductors.

Abstract: Safety control apparatus for limiting voltages on electrical conductors included in a motor power cable that are connected to a motor of an electrical submersible pump assembly are described. The safety control apparatus include circuitry, which when electrically coupled to the electrical conductors of the motor power cable, is configured to controllably connect and disconnect the electrical conductors to and from, respectively, a motor load element, to provide a braking function limiting the motor rotational speed, and thereby limit the voltage level that the rotation of the motor may induce onto the electrical conductors.

Abstract: Processing device-based systems and methods for controlling an electric motor of an electric submersible pump system in a balanced current condition using a variable speed drive despite an impedance imbalance of an electric cable connecting the electric motor to the variable speed drive. The systems and methods can utilize estimated motor shaft angular position and speed values, as well as values of three-phase motor currents measured at an output of an inverter of the variable speed drive as input information. Positive-sequence and negative-sequence current components may be extracted from measured current values and compared to reference values. The system provides an overall voltage command in the abc reference frame to a pulse width modulation controller, which generates an inverter switching pattern that will control the electric motor of the electric submersible pump system in a balanced current condition.

Abstract: Systems, methods, and apparatus, including computer programs encoded on computer-readable media, for monitoring an electromotive force (EMF) for an electrical submersible pump (ESP) having a permanent magnet motor (PMM) are disclosed. One or more voltages and one or more currents may be monitored in a cable coupled to the ESP having the PMM and being used in a well system. It may be determined whether at least one of the one or more voltages in the cable exceeds a voltage threshold and whether at least one of the one or more currents in the cable exceeds a current threshold. A notification may be generated to indicate an EMF condition if at least one of the one or more voltages and the one or more currents in the cable exceeds at least one of the one or more thresholds.

Abstract: Processing device-based systems and methods for controlling an electric motor of an electric submersible pump system in a balanced current condition using a variable speed drive despite an impedance imbalance of an electric cable connecting the electric motor to the variable speed drive. The systems and methods can utilize estimated motor shaft angular position and speed values, as well as values of three-phase motor currents measured at an output of an inverter of the variable speed drive as input information. Positive-sequence and negative-sequence current components may be extracted from measured current values and compared to reference values. The system provides an overall voltage command in the abc reference frame to a pulse width modulation controller, which generates an inverter switching pattern that will control the electric motor of the electric submersible pump system in a balanced current condition.