Method and apparatus for controlling a submergible pumping system

A control system for a submergible pumping system positionable in a well, the pumping unit submergible in fluids within the well including a pump and an electric motor operatively coupled to the pump, the control system comprising:

• a command circuit configured to receive an input command signal representative of a desired operational parameter of the pumping unit;
• a power supply circuit coupled to the command circuit, the power supply circuit being configured to receive alternating current electrical power from a source and to convert the alternating current electrical power to direct current electrical power having a voltage level based upon the desired operational parameter;
• and
• a direct current bus cable coupled to the power supply circuit and to the pumping unit for transmitting the direct current electrical power to the pumping unit.

A method for controlling a submergible pumping system, the system including a pump operatively coupled to an electric motor, the system being positionable within a well to pump viscous fluid within the well, the method comprising the steps of:

• (a) electrically coupling a power supply circuit to the pumping system via a direct current bus cable, the power supply circuit being disposed outside the well;
• (b) at least partially submerging the pumping system in the viscous fluids within the well;
• (c) generating a command signal representative of a desired operating parameter of the pump;
• (d) converting alternating current electrical power from a source to direct current electrical power in the power supply circuit, the direct current electrical power having a voltage level based upon the command signal;
• and
• (e) transmitting the direct current electrical power to the pumping system via the direct current bus cable to energize the motor and drive the pump.

A method for controlling a submergible pumping system including an electric motor operatively coupled to a pump, the system being submergible in viscous fluids within a well for pumping the fluids from the well, the method comprising the steps of:

• (a) electrically coupling the electric motor to a power supply system, the power supply system including a power supply circuit disposed outside the well, a switching circuit disposed adjacent to and electrically coupled to the electric motor, and a direct current bus cable electrically coupled between the power supply circuit and the switching circuit;
• (b) at least partially submerging the pumping system in the viscous fluid;
• (c) converting alternating current electrical power to direct current electrical power in the power supply circuit, an electrical parameter of the direct current electrical power being based upon a desired operating parameter of the pumping system;
• (d) applying the direct current electrical power to the switching circuit via the direct current bus cable;
• and
• (e) applying the direct current electrical power to the electric motor from the switching circuit.

A method for controlling a submergible pumping system including an electric motor operatively coupled to a pump, the system being submergible in a viscous fluid within a well for pumping the fluid from the well, the method comprising the steps of:

• (a) electrically coupling a power supply circuit to the pumping system via a direct current bus cable, the power supply circuit being disposed outside the well;
• (b) at least partially submerging the pumping system in the viscous fluid within the well;
• and
• (c) applying variable voltage direct current power from the power supply circuit to the pumping system to drive the pump at a desired speed.