Abstract: A regenerative drive system includes a plurality of power cells receiving power from a source and supplying power to one or more output phases, wherein each power cell is operable in multiple operation modes, each power cell including multiple switching devices including active front-end switching devices, and a central control system controlling operation of the plurality of power cells, wherein the central control system is configured to control the active front-end switching devices of each power cell with variable conduction angles in the multiple operation modes.

Abstract: Provided are embodiments for a system for reducing input harmonic distortion of a power supply. The system includes a power source coupled to a power supply. The power supply includes an input stage that is configured to receive an input signal from the power-supply, wherein the input signal is received at known input frequency, and a converting stage that is operated to convert the input signal to an output signal, wherein the output signal has an output frequency. The power supply also includes an output stage that is operated to generate output power based on the output signal, and a controller that is configured to provide control signals to the output stage of the power supply to modify the output signal. Also provided are embodiments for a power supply and method for reducing input harmonic distortion of the power supply.

Abstract: A system (500) for controlling a linear alternating current (AC) electrodynamic machine (400) includes a linear AC electrodynamic machine (400) with a stationary part (410) with a plurality of discrete stationary sections (412, 414, 416), each stationary section (412, 414, 416) having a poly-phase circuit; a variable frequency drive (VFD) (510) configured to be coupled to a utility power source and to provide output currents, wherein the VFD (510) is operable coupled to the stationary part (410) of the linear AC electrodynamic machine (400) for powering and controlling the stationary sections (412, 414, 416) of the stationary part (410); and a plurality of switches (512, 514, 516) coupled between the VFD (510) and the stationary part (410), wherein the plurality of switches (512, 514, 516) allow connecting or disconnecting the VFD (510) to or from the stationary sections (412, 414, 416).

Abstract: Provided are embodiments for a system for reducing input harmonic distortion of a power supply. The system includes a power source coupled to a power supply. The power supply includes an input stage that is configured to receive an input signal from the power-supply, wherein the input signal is received at known input frequency, and a converting stage that is operated to convert the input signal to an output signal, wherein the output signal has an output frequency. The power supply also includes an output stage that is operated to generate output power based on the output signal, and a controller that is configured to provide control signals to the output stage of the power supply to modify the output signal. Also provided are embodiments for a power supply and method for reducing input harmonic distortion of the power supply.

Abstract: A system (500) for controlling a linear alternating current (AC) electrodynamic machine (400) includes a linear AC electrodynamic machine (400) with a stationary part (410) with a plurality of discrete stationary sections (412, 414, 416), each stationary section (412, 414, 416) having a poly-phase circuit; a variable frequency drive (VFD) (510) configured to be coupled to a utility power source and to provide output currents, wherein the VFD (510) is operable coupled to the stationary part (410) of the linear AC electrodynamic machine (400) for powering and controlling the stationary sections (412, 414, 416) of the stationary part (410); and a plurality of switches (512, 514, 516) coupled between the VFD (510) and the stationary part (410), wherein the plurality of switches (512, 514, 516) allow connecting or disconnecting the VFD (510) to or from the stationary sections (412, 414, 416).

Abstract: Systems and method for controlling an alternating current (AC) electrodynamic machine (390) with a variable frequency drive (VFD) (380) include a control system (300) with a phase-locked-loop (PLL) circuit (382) for providing a stator flux angle signal (338) to the VFD (380), the PLL circuit (382) comprising a proportional integral (PI) regulator (332) providing an output signal (334); and a feedforward generator (350) in communication with the PLL circuit (382), wherein the feedforward generator (350) tracks a stator flux position of the AC electrodynamic machine (390) such that the feedforward generator (350) determines a stator frequency signal (352) based on stator flux signals (308, 310, 312) and supplies the stator frequency signal (352) downstream of the PI regulator (332), and wherein the stator frequency signal (352) is summed with the output signal (334) of the PI regulator (332) to provide a dynamically adapted output signal (335) of the PI regulator (332), and wherein the adapted output signal (33

Abstract: An electrical contact assembly includes a contact apparatus with stationary first and second contact members, a movable contact member having a generally planar profile and an armature operable to produce a force to cause the movable contact member to remain closed upon application of current through the first contact member, the movable contact member, and second contact member, and an actuator mechanism coupled to a side of the movable contact member and adapted to open and close the contact apparatus.

Abstract: Systems and method for controlling an alternating current (AC) electrodynamic machine (390) with a variable frequency drive (VFD) (380) include a control system (300) with a phase-locked-loop (PLL) circuit (382) for providing a stator flux angle signal (338) to the VFD (380), the PLL circuit (382) comprising a proportional integral (PI) regulator (332) providing an output signal (334); and a feedforward generator (350) in communication with the PLL circuit (382), wherein the feedforward generator (350) tracks a stator flux position of the AC electrodynamic machine (390) such that the feedforward generator (350) determines a stator frequency signal (352) based on stator flux signals (308, 310, 312) and supplies the stator frequency signal (352) downstream of the PI regulator (332), and wherein the stator frequency signal (352) is summed with the output signal (334) of the PI regulator (332) to provide a dynamically adapted output signal (335) of the PI regulator (332), and wherein the adapted output signal (33

Abstract: A system for soft starting a large AC motor may include a variable frequency drive (VFD) having a much lower voltage rating than the rated voltage of the AC motor. The VFD's voltage rating may be in a range of about 33% to about 67% of the AC motor's rated voltage. The AC motor may be coupled to a utility power source via conventional connections to leads of the AC motor's windings. The VFD may be connected to the AC motor via tapped connections within the windings of the AC motor such that the tap voltages are much less than the AC motor's rated voltage. A less expensive VFD may therefore be used to soft start the AC motor instead of a VFD having the same rated voltage as the AC motor. Methods of starting large AC motors with a VFD are also provided, as are other aspects.

Abstract: An electrical contact apparatus is disclosed. The contact apparatus has first contact member having a first contact, a movable contact member received adjacent to the first contact member, the movable contact member having an opposing contact positioned adjacent the first contact, and an armature operable to produce an electromagnetic closing force to cause the movable contact member to remain closed upon application of current through the first contact member, movable contact member. Contact assemblies and methods of operating the contact apparatus are disclosed, as are other aspects.

Abstract: A power electronic device is disclosed. The power electronic device may include a housing, a conductive element positioned within the housing and rated for at least a medium voltage, a cooling system in fluid communication with the conductive element, a plurality of temperature sensing tags and a data collection unit having a receiver that is configured to receive signals from the antennae of the temperature sensing tags. The cooling system may have a plurality of outlet conduit elements that are positioned within the housing. Each of the tags may be attached to one of the outlet conduits and may include a power supply, a temperature sensor, and an antenna.

Abstract: A power electronic device is disclosed. The power electronic device may include a housing, a conductive element positioned within the housing and rated for at least a medium voltage, a cooling system in fluid communication with the conductive element, a plurality of temperature sensing tags and a data collection unit having a receiver that is configured to receive signals from the antennae of the temperature sensing tags. The cooling system may have a plurality of outlet conduit elements that are positioned within the housing. Each of the tags may be attached to one of the outlet conduits and may include a power supply, a temperature sensor, and an antenna.

Abstract: An electrical contact apparatus is disclosed. The contact apparatus has first contact member having a first contact, a movable contact member received adjacent to the first contact member, the movable contact member having an opposing contact positioned adjacent the first contact, and an armature operable to produce an electromagnetic closing force to cause the movable contact member to remain closed upon application of current through the first contact member, movable contact member. Contact assemblies and methods of operating the contact apparatus are disclosed, as are other aspects.

Abstract: A system for soft starting a large AC motor may include a variable frequency drive (VFD) having a much lower voltage rating than the rated voltage of the AC motor. The VFD's voltage rating may be in a range of about 33% to about 67% of the AC motor's rated voltage. The AC motor may be coupled to a utility power source via conventional connections to leads of the AC motor's windings. The VFD may be connected to the AC motor via tapped connections within the windings of the AC motor such that the tap voltages are much less than the AC motor's rated voltage. A less expensive VFD may therefore be used to soft start the AC motor instead of a VFD having the same rated voltage as the AC motor. Methods of starting large AC motors with a VFD are also provided, as are other aspects.

Abstract: A system for braking a motor. The system includes at least one resistor and a contactor connected to the at least one resistor and a motor. The system further includes a variable frequency drive electrically connected to the motor, wherein the variable frequency drive comprises a controller operably connected to the contactor, wherein at least a portion of the contactor closes connecting the at least one resistor to the motor in response to a command from the controller. The variable frequency drive is configured such that motor flux levels may be maintained at a relatively high level as motor torque current is reduced, resulting in a consistently high motor flux level as the motor speed decreases.

Abstract: A starting method and system for a motor where the motor may be started as an induction motor by applying a magnetizing current to build flux through the stator, with the field current set at the maximum permissible exciter stator current (i.e., the current that will cause rated no-load current in the main field at the transition speed). The motor stator currents will be maintained at a value that allows the motor to generate sufficient breakaway torque to overcome any stiction. At a specific transition speed or after a period of time, the drive will initiate a transition from induction motor control to synchronous motor control by removing the initial magnetizing current, and a field current is then applied to the motor through the DC exciter. Once this transition is completed, the drive may ramp up to the desired speed demand.

Abstract: A three-phase, multi-winding includes a core, the core including a hub and an outer shell around a perimeter of the hub. wherein the hub and the outer shell are in a fixed position with respect to each other. The core also includes multiple slots. In addition to the core, the multi-winding device includes a primary winding positioned in at least two of the slots; and multiple spatially distributed secondary windings, wherein at least one of the secondary windings is positioned proximate the primary winding in at least one of the two slots.

Abstract: A system for braking a motor. The system includes at least one resistor and a contactor connected to the at least one resistor and a motor. The system further includes a variable frequency drive electrically connected to the motor, wherein the variable frequency drive comprises a controller operably connected to the contactor, wherein at least a portion of the contactor closes connecting the at least one resistor to the motor in response to a command from the controller. The variable frequency drive is configured such that motor flux levels may be maintained at a relatively high level as motor torque current is reduced, resulting in a consistently high motor flux level as the motor speed decreases.

Abstract: An electrical device includes a plurality of single-phase power cells electrically connected to receive power from a source and deliver power to a load. The single-phase power cells include a first rank of regenerative power cells and a second rank of non-regenerative power cells. Each non-regenerative power cell may include an inverter bridge, a capacitor set electrically connected across terminals of the inverter bridge, and a three-phase bridge rectifier electrically connected across the terminals. The non-regenerative power cells may provide reactive power when the plurality of cells are used for braking of a motor.

Abstract: A three-phase, multi-winding includes a core, the core including a hub and an outer shell around a perimeter of the hub. wherein the hub and the outer shell are in a fixed position with respect to each other. The core also includes multiple slots. In addition to the core, the multi-winding device includes a primary winding positioned in at least two of the slots; and multiple spatially distributed secondary windings, wherein at least one of the secondary windings is positioned proximate the primary winding in at least one of the two slots.