Abstract: A submersible well fluid system for operating submerged in a body of water may include an electric machine and a fluid end. The electric machine includes a rotor and a stator residing in a first housing at specified conditions. The fluid end may include an impeller and be coupled to the electric machine. The submersible well fluid system may also include an adjustable speed drive for the electric machine in the housing. The submersible well fluid system may also include a chemical distribution system for supplying treatment chemicals to the submersible well fluid system, a barrier fluid supply system for supplying a barrier fluid to the submersible well fluid system, and a pressure management system.

Abstract: A submersible well fluid system for operating submerged in a body of water may include an electric machine and a fluid end. The electric machine includes a rotor and a stator residing in a first housing at specified conditions. The fluid end may include an impeller and be coupled to the electric machine. The submersible well fluid system may also include an adjustable speed drive for the electric machine in the housing. The submersible well fluid system may also include a chemical distribution system for supplying treatment chemicals to the submersible well fluid system, a barrier fluid supply system for supplying a barrier fluid to the submersible well fluid system, and a pressure management system.

Abstract: A first line-to-line terminal voltage of a three-phase electric motor is measured while the three-phase electric motor free-spins. A second line-to-line terminal voltage of a three-phase electric motor is measured while the three-phase electric motor free-spins. A motor's rotor position is determined based on the first line-to-line terminal voltage and the second line-to-line terminal voltage. Three-phase current is sent to the motor after the rotor position has been determined. The three-phase current being in-phase with the rotor position.

Abstract: Certain aspects of the subject matter described here can be implemented in a downhole-type electric submersible pump system. An electric machine can be disposed downhole in a wellbore. The electric machine is coupled to rotate with an impeller that can be disposed downhole in the wellbore. The electric machine includes a stator assembly with at least three stator sections axially arranged and spaced apart from each other along a longitudinal axis of the electric machine. The electric machine also includes a rotor assembly with at least three rotor sections arranged axially along the longitudinal axis of the electric machine. The rotor assembly is carried within and supported to rotate by the stator assembly.

Abstract: A first line-to-line terminal voltage of a three-phase electric motor is measured while the three-phase electric motor free-spins. A second line-to-line terminal voltage of a three-phase electric motor is measured while the three-phase electric motor free-spins. A motor's rotor position is determined based on the first line-to-line terminal voltage and the second line-to-line terminal voltage. Three-phase current is sent to the motor after the rotor position has been determined. The three-phase current being in-phase with the rotor position.

Abstract: A submersible fluid system for operating submersed in a body of water includes an electric machine and a fluid-end. The fluid-end includes a fluid-end housing having an inlet to a fluid rotor, the fluid rotor coupled to the electric machine and carried to rotate in the housing by a bearing in the housing. A fluid separator system receives a multiphase fluid and communicates a flow of the fluid to the inlet and a substantially liquid flow extracted from the multiphase fluid to the bearing.

Abstract: A submersible well fluid system for operating submerged in a body of water may include an electric machine and a fluid end. The electric machine includes a rotor and a stator residing in a first housing at specified conditions. The fluid end may include an impeller and be coupled to the electric machine. The submersible well fluid system may also include an adjustable speed drive for the electric machine in the housing. The submersible well fluid system may also include a chemical distribution system for supplying treatment chemicals to the submersible well fluid system, a barrier fluid supply system for supplying a barrier fluid to the submersible well fluid system, and a pressure management system.

Abstract: A submersible well fluid system for operating submerged in a body of water may include an electric machine and a fluid end. The electric machine includes a rotor and a stator residing in a first housing at specified conditions. The fluid end may include an impeller and be coupled to the electric machine. The submersible well fluid system may also include an adjustable speed drive for the electric machine in the housing. The submersible well fluid system may also include a chemical distribution system for supplying treatment chemicals to the submersible well fluid system, a barrier fluid supply system for supplying a barrier fluid to the submersible well fluid system, and a pressure management system.

Abstract: A submersible fluid system for operating submerged in a body of water includes a fluid-end that has a fluid rotor disposed in a fluid-end housing. An electric machine housing is coupled to the fluid-end housing and includes a hermetically sealed cavity. An electric machine, such as a motor and/or generator, is disposed entirely within the cavity of the electric machine housing. The electric machine includes an electric machine stator and an electric machine rotor. A magnetic coupling couples the electric machine rotor and the fluid rotor.

Abstract: Certain aspects of the subject matter described here can be implemented in a downhole-type electric submersible pump system. An electric machine can be disposed downhole in a wellbore. The electric machine is coupled to rotate with an impeller that can be disposed downhole in the wellbore. The electric machine includes a stator assembly with at least three stator sections axially arranged and spaced apart from each other along a longitudinal axis of the electric machine. The electric machine also includes a rotor assembly with at least three rotor sections arranged axially along the longitudinal axis of the electric machine.

Abstract: A submersible fluid system for operating submerged in a body of water includes a fluid-end with a fluid rotor disposed in a fluid-end housing. An electric machine housing is coupled to the fluid-end housing and has a hermetically sealed cavity containing a fluid at a pressure less than a hydrostatic pressure at a specified depth at which the submersible fluid system is designed to operate. An electric machine is disposed in the cavity of the electric machine housing and includes an electric machine rotor coupled to the fluid rotor and an electric machine stator.

Abstract: A submersible well fluid system for operating submerged in a body of water may include an electric machine and a fluid end. The electric machine includes a rotor and a stator residing in a first housing at specified conditions. The fluid end may include an impeller and be coupled to the electric machine. The submersible well fluid system may also include an adjustable speed drive for the electric machine in the housing. The submersible well fluid system may also include a chemical distribution system for supplying treatment chemicals to the submersible well fluid system, a barrier fluid supply system for supplying a barrier fluid to the submersible well fluid system, and a pressure management system.

Abstract: A submersible fluid system for operating submersed in a body of water includes an electric machine and a fluid-end. The fluid-end includes a fluid-end housing having an inlet to a fluid rotor, the fluid rotor coupled to the electric machine and carried to rotate in the housing by a bearing in the housing. A fluid separator system receives a multiphase fluid and communicates a flow of the fluid to the inlet and a substantially liquid flow extracted from the multiphase fluid to the bearing.

Abstract: A submersible fluid system for operating submerged in a body of water includes a fluid-end with a fluid rotor disposed in a fluid-end housing. An electric machine housing is coupled to the fluid-end housing and has a hermetically sealed cavity containing a fluid at a pressure less than a hydrostatic pressure at a specified depth at which the submersible fluid system is designed to operate. An electric machine is disposed in the cavity of the electric machine housing and includes an electric machine rotor coupled to the fluid rotor and an electric machine stator.

Abstract: A submersible fluid system for operating submerged in a body of water includes a fluid-end that has a fluid rotor disposed in a fluid-end housing. An electric machine housing is coupled to the fluid-end housing and includes a hermetically sealed cavity. An electric machine, such as a motor and/or generator, is disposed entirely within the cavity of the electric machine housing. The electric machine includes an electric machine stator and an electric machine rotor. A magnetic coupling couples the electric machine rotor and the fluid rotor.

Abstract: An electrical machine having a centrifugal compressor for producing a fluid flow to cool one or more portions thereof. In one embodiment, the fluid is separated into separate flows, each of the flows flowing through only a portion of an annular gap formed between a rotor and stator of the electrical machine. According to some embodiments, the centrifugal compressor pushes a fluid through the electrical machine, whereas, in other embodiments, the centrifugal compressor pulls the fluid through the electrical machine. The centrifugal compressor includes an impeller that is attached to a shaft of the rotor. According to other embodiments, the electrical machine may include longitudinal channels formed between a housing of the electrical machine and the stator. A first flow of the fluid travels through the annular gap, and a second flow travels through the longitudinal channels. The electrical machine may also include a damper disposed in the longitudinal channels.

Abstract: An electrical machine having a centrifugal compressor for producing a fluid flow to cool one or more portions thereof. In one embodiment, the fluid is separated into separate flows, each of the flows flowing through only a portion of an annular gap formed between a rotor and stator of the electrical machine. According to some embodiments, the centrifugal compressor pushes a fluid through the electrical machine, whereas, in other embodiments, the centrifugal compressor pulls the fluid through the electrical machine. The centrifugal compressor includes an impeller that is attached to a shaft of the rotor. According to other embodiments, the electrical machine may include longitudinal channels formed between a housing of the electrical machine and the stator. A first flow of the fluid travels through the annular gap, and a second flow travels through the longitudinal channels. The electrical machine may also include a damper disposed in the longitudinal channels.

Abstract: A rotor construction may comprise a rotor with a centrally located permanent magnet section having aligned magnet segments and having a central hole throughout its length. A thin rod of magnetic steel is located in this central hole to support the permanent magnets from within. At each end of the rod are located threaded sections for attachment to supporting end stubs. A high strength steel sleeve is interference fit over both the magnets and the end stubs to provide a mechanical link from stub to stub. The guide rod insures that the end stubs and central magnet are concentric during initial processing, prevents relative motion between the rotor components and provides support for the magnet once the sleeve is installed.

Abstract: An optimized flywheel energy storage system utilizing magnetic bearings, a high speed permanent magnet motor/generator, and a flywheel member. The flywheel system is constructed using a high strength steel wheel for kinetic energy storage, high efficiency magnetic bearings configured with dual thrust acting permanent magnet combination bearings, and a high efficiency permanent magnet motor generator. The steel wheel provides a cost effective, high speed construction for the energy storage rotor.

Abstract: An improved magnetic bearing that uses permanent magnets to provide the bias flux. The magnetic circuits generating the control flux and bias fluxes are substantially non-coincident but share the same path over some portions that include radial and axial airgaps allowing for a low reluctance and an efficient path for the electromagnetic flux. The flux paths of the permanent magnets are completely defined with minimized airgaps for achieving higher forces and efficiency and very low control currents that produce extremely large forces. A single coil and amplifier for the axial force control and two coils with one associated amplifier for each radial axis of control provides simplicity and cost effectiveness. A single thrust disk is provided that is reacted against for both radial and the axial displacement.