Abstract: A system for detecting a backspin condition of a motor in an electrical submersible pump is described herein. The system comprises a variable speed drive for powering the motor via a power cable; and a controller, the controller having a memory, a computer processor, and a computer program product stored on the memory and executable by the processor. The computer program product comprises the instructions of: monitoring an input current or impedance on the power cable to determine changes in motor current impedance, comparing changes in the motor current impedance to a historical threshold value for backspin events to determine whether the motor is backspinning; impeding operable power to the motor when it is determined the motor is backspinning; supplying a low AC voltage to the motor after it is determined the motor is backspinning; and determining whether or not the motor has stopped backspinning by monitoring the low AC voltage.

Abstract: Systems and methods for controlling an electrical drive such as is used with electric submersible pumps used in downhole oil production, wherein the drive automatically determines the proper phasing to drive the pump motor in a forward direction. In one embodiment, a method includes generating a drive signal having an initial phasing and driving the pump to establish a column of fluid in the borehole. The drive signal is then discontinued, allowing the column of fluid to fall through the pump and cause the pump to backspin and generate a signal having phasing corresponding to the reverse rotational direction. The forward phasing is then determined to be the opposite of the phasing corresponding to the reverse rotational direction. The pump can be restarted in the forward direction, or an operator can be notified of the proper phasing to produce forward rotation of the pump.

Abstract: Systems and methods for using variable speed drives to restart downhole submersible pump motors. In one embodiment, a downhole pump is controlled using a variable speed drive that includes a control system configured to detect interruptions in the operation of the pump system. After an interruption that requires the restart of the pump motor, the control system determines the reverse rotational speed of the pump motor and restarts the motor when this speed is sufficiently low. The control system may be configured to reduce the output voltage of the variable speed drive and sweep through a range of output frequencies to determine the frequency at which the current drawn by the motor is lowest. This is the frequency at which the drive's output matches the speed of the motor and the apparent impedance of the motor is highest. When the speed is low enough, the motor is restarted.

Abstract: A system for detecting a backspin condition of a motor in an electrical submersible pump is described herein. The system comprises a variable speed drive for powering the motor via a power cable; and a controller, the controller having a memory, a computer processor, and a computer program product stored on the memory and executable by the processor. The computer program product comprises the instructions of: monitoring an input current or impedance on the power cable to determine changes in motor current impedance, comparing changes in the motor current impedance to a historical threshold value for backspin events to determine whether the motor is backspinning; impeding operable power to the motor when it is determined the motor is backspinning; supplying a low AC voltage to the motor after it is determined the motor is backspinning; and determining whether or not the motor has stopped backspinning by monitoring the low AC voltage.

Abstract: Systems and methods for controlling an electrical drive such as is used with electric submersible pumps used in downhole oil production, wherein the drive automatically determines the proper phasing to drive the pump motor in a forward direction. In one embodiment, a method includes generating a drive signal having an initial phasing and driving the pump to establish a column of fluid in the borehole. The drive signal is then discontinued, allowing the column of fluid to fall through the pump and cause the pump to backspin and generate a signal having phasing corresponding to the reverse rotational direction. The forward phasing is then determined to be the opposite of the phasing corresponding to the reverse rotational direction. The pump can be restarted in the forward direction, or an operator can be notified of the proper phasing to produce forward rotation of the pump.

Abstract: Systems and methods for using variable speed drives to restart downhole submersible pump motors. In one embodiment, a downhole pump is controlled using a variable speed drive that includes a control system configured to detect interruptions in the operation of the pump system. After an interruption that requires the restart of the pump motor, the control system determines the reverse rotational speed of the pump motor and restarts the motor when this speed is sufficiently low. The control system may be configured to reduce the output voltage of the variable speed drive and sweep through a range of output frequencies to determine the frequency at which the current drawn by the motor is lowest. This is the frequency at which the drive's output matches the speed of the motor and the apparent impedance of the motor is highest. When the speed is low enough, the motor is restarted.