Abstract: A multi-stage pump includes a first set of pump stages directing fluid in a first direction from a first end of the multi-stage pump to a diffuser casing disposed at a central portion of the multi-stage pump. A second set of pump stages directs the fluid expelled from the diffuser casing in a second direction, opposite to the first direction, from a second end of the multi-stage pump to the diffuser casing. The diffuser casing receives the fluid from the first set of pump stages and directs the fluid toward the second end of the multi-stage pump and receives the fluid from the second set of pump stages and directs the fluid in a radial direction with respect to a longitudinal axis of the multi-stage pump.

Abstract: Arrangements for promoting the restriction of fluid flow along a shaft via providing a deformable ring member in an annulus between the shaft and housing. In an initial general condition, the deformable ring member permits free fluid flow in a general direction along the shaft while in a second, constricted condition, the deformable ring closes or blocks a gap or clearance normally conducive to free fluid flow to thereby restrict fluid flow. An actuation medium, which can take any of a very wide variety of forms, preferably promotes constriction of the deformable ring member directly or indirectly.

Abstract: A heat shield for a thrust bearing assembly of a pump. The heat shield includes a member having an inner surface and an outer surface. A raised flange is formed on a perimeter of the inner surface. The raised flange is configured to seal with a back surface of a thrust shoe holder, and form a cavity between the inner surface and the back surface of the thrust shoe holder. At least one weep hole is on the flange. The weep hole is configured to allow water to enter the cavity to form an insulating stagnant water layer.

Abstract: A control system for a harmonic neutralized frequency changer. The control system includes a processor, a narrow band harmonic controller and a fundamental current controller. The narrow band harmonic controller is communicably connected to the processor and is configured to reduce a positive sequence component, a negative sequence component and a zero sequence component of a harmonic generated by a cycloconverter of the harmonic neutralized frequency changer. The fundamental current controller is communicably connected to the processor and is configured to reduce a fundamental frequency component of current flowing in a neutralization inverter of the harmonic neutralized frequency changer.

Abstract: A system. The system includes a processor, a first module, a second module and a third module. The first module is communicably connected to the processor and is configured for calculating a q-axis voltage component and a d-axis voltage component. The second module is communicably connected to the processor and is configured for determining a voltage angle relative to the q-axis. The third module is communicably connected to the processor and is configured for (1) comparing the determined voltage angle to a predetermined value, (2) outputting the determined voltage angle if the determined voltage angle is less than the predetermined value, and (3) outputting the predetermined value if the predetermined value is less than the determined voltage angle.

Abstract: Arrangements for promoting the restriction of fluid flow along a shaft via providing a deformable ring member in an annulus between the shaft and housing. In an initial general condition, the deformable ring member permits free fluid flow in a general direction along the shaft while in a second, constricted condition, the deformable ring closes or blocks a gap or clearance normally conducive to free fluid flow to thereby restrict fluid flow. An actuation medium, which can take any of a very wide variety of forms, preferably promotes constriction of the deformable ring member directly or indirectly.

Abstract: Arrangements for promoting the restriction of fluid flow along a shaft via providing a deformable ring member in an annulus between the shaft and housing. In an initial general condition, the deformable ring member permits free fluid flow in a general direction along the shaft while in a second, constricted condition, the deformable ring closes or blocks a gap or clearance normally conducive to free fluid flow to thereby restrict fluid flow. An actuation medium, which can take any of a very wide variety of forms, preferably promotes constriction of the deformable ring member directly or indirectly.

Abstract: A two-level two-terminal modular multilevel converter subsystem. The subsystem includes a first capacitor and a second capacitor. The modular multilevel converter subsystem is configured to selectively place the first capacitor in series with the second capacitor. The modular multilevel converter subsystem is also configured to selectively place the first capacitor in parallel with the second capacitor relative to first and second output terminals of the modular multilevel converter subsystem.

Abstract: A modular multilevel converter system. The system includes a plurality of series connected two-terminal M2LC subsystems and a control system module. The two-terminal M2LC subsystems are arranged into at least two output phase modules. A first one of the output phase modules defines a total value of inductance and includes a positive arm and a negative arm. The control system module is configured to apply selectively reassigned modulated switch functions to only one of the following at a given instance of time: the two-terminal M2LC subsystems of the positive arm of the first one of the output phase modules or the two-terminal M2LC subsystems of the negative arm of the first one of the output phase modules. The selective reassigning of the modulated switch functions forces charge balance of the individual capacitors of the series connected two-terminal M2LC subsystems at a predetermined rate.

Abstract: A modular multilevel converter system. The system includes a plurality of series connected two-terminal M2LC cells arranged into at least two output phase modules. A first one of the output phase modules has an inductance and an effective capacitance associated therewith. The first one of the output phase modules is configured so that a natural resonant frequency of the inductance with the effective capacitance of the first one of the output phase modules is greater than at least one of the following: an operating frequency of the first one of the output phase modules; a switching frequency of the first one of the output phase modules; and a switching frequency of any of the M2LC cells of the first one of the output phase modules.

Abstract: A preload assembly for a thrust bearing. The preload assembly includes a carrier plate having a central annular protrusion, wherein the annular protrusion has an inner diameter and an outer diameter; an inner disc spring; an outer disc spring; and a housing having an annular channel for housing the carrier plate, the inner disc spring, and the outer disc spring.

Abstract: A system. The system includes a processor, a first module, a second module and a third module. The first module is communicably connected to the processor and is configured for calculating a q-axis voltage component and a d-axis voltage component. The second module is communicably connected to the processor and is configured for determining a voltage angle relative to the q-axis. The third module is communicably connected to the processor and is configured for (1) comparing the determined voltage angle to a predetermined value, (2) outputting the determined voltage angle if the determined voltage angle is less than the predetermined value, and (3) outputting the predetermined value if the predetermined value is less than the determined voltage angle.

Abstract: A system. The system is a modular multilevel converter system and includes a plurality of series connected modular multilevel converter cells. At least one of the modular multilevel converter cells is a three-level modular multilevel converter cell. The plurality of series connected modular multilevel converter cells are coupled to a rectifier system via a DC bus.

Abstract: A modular multilevel converter system. The system includes a plurality of series connected two-terminal M2LC subsystems and a control system module. The two-terminal M2LC subsystems are arranged into at least two output phase modules. A first one of the output phase modules defines a total value of inductance and includes a positive arm and a negative arm. The control system module is configured to apply selectively reassigned modulated switch functions to only one of the following at a given instance of time: the two-terminal M2LC subsystems of the positive arm of the first one of the output phase modules or the two-terminal M2LC subsystems of the negative arm of the first one of the output phase modules. The selective reassigning of the modulated switch functions forces charge balance of the individual capacitors of the series connected two-terminal M2LC subsystems at a predetermined rate.

Abstract: A two-level two-terminal modular multilevel converter subsystem. The subsystem includes a first capacitor and a second capacitor. The modular multilevel converter subsystem is configured to selectively place the first capacitor in series with the second capacitor. The modular multilevel converter subsystem is also configured to selectively place the first capacitor in parallel with the second capacitor relative to first and second output terminals of the modular multilevel converter subsystem.

Abstract: A system. The system is a modular multilevel converter system and includes a plurality of series connected two-terminal modular multilevel converter subsystems. The subsystems are magnetically coupled to an AC current source power supply.

Abstract: Systems and methods for improving the current pulse from multiple pairs of pulsed alternators used for driving large loads such as an electromagnetic launcher (i.e., “rail gun”) load. Conventional current pulse ripples are reduced by interleaving pulses from multiple pairs of contra-rotating pulsed alternators. Current pulses supplied by different pairs of pulsed alternators are timed so that they are interspersed between one another to provide more pulses for a given launch time. The interleaved current pulses increase the frequency and reduce the magnitude of the ripple on the average load current.

Abstract: A combined canned motor-pump operates directly in the process fluid without the need for shaft seals or buffer or lubricating fluids. The pump incorporates an integral gas-separating system that includes gas separating hydraulics and a flow path that returns the gas to the main gas/oil separator. The gas-separating system includes a pump inlet for accepting incoming multiphase flow, at least one blade rotatable about the axis of rotation, an open annulus region for separating gas from liquid in the multiphase flow, at least one radial hole in the shaft for directing separated gas to the axial hole, and a pump outlet for discharging liquid from the pump.

Abstract: In subsea multiphase pumping systems, the use of a gas-liquid cylindrical cyclone (GLCC) as a separator to recirculate liquid from pump discharge to pump suction, especially during high gas inlet conditions from a multiphase petroleum stream. Further contemplated is protection of the pump from momentary high gas inlet conditions due to an incoming slug flow profile from a petroleum stream, via transforming a naturally varying multiphase petroleum stream into separated phases for measured distribution to the pump suction and ensuring a minimum liquid flow.

Abstract: A control and regulation system for use with a harmonic neutralization frequency changer system. In the generalized frequency changer system, a direct converter frequency changer is used to convert bulk power, but unwanted harmonics are introduced. Input and output power distortion is monitored by a control system, and groups of high performance inverters inject shunt/series harmonic currents/voltages into a specially designed transformer to neutralize the power distortion to a specific acceptable level. Two control strategies are used including one that is based on discrete narrow band harmonic regulation and another that is based on wide band harmonic control. Each of these control strategies can be used at the input and/or output of the frequency changer and can be injected using shunt-current and series-voltage schemes.