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 variable frequency drive system (300) includes a power converter (310) with a plurality of power cells supplying power to one or more output phases (A, B, C), a main power source (320) for providing main input power to the power converter (310), an auxiliary power source (330) for providing auxiliary input power to the power converter (310), and a control system (314) in communication with the power converter (310) and controlling operation of the plurality of power cells, wherein the control system (314) comprises one or more processor(s) (315) configured via computer executable instructions to detect a main input voltage drop of the main power source (320) below a predefined power threshold, disconnect the main power source (320) in response to the main input voltage drop, and enable the auxiliary power source (330) to provide auxiliary input power to the power converter (310) in response to the main input voltage drop.

Abstract: A printed circuit board power cell having a printed circuit board including a DC bus disposed within the printed circuit board. The printed circuit board power cell includes a plurality of capacitors connected to the DC bus, a three-phase AC input disposed on the printed circuit board and a single-phase AC output disposed on the printed circuit board. The printed circuit board power cell also includes a power module connected to the DC bus, the three-phase AC input and the single-phase AC output, wherein the power module receives three phase AC input power via the three-phase AC input and responsively outputs a single-phase AC power via the single-phase AC output.

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 variable frequency drive system (300) includes a power converter (310) with a plurality of power cells supplying power to one or more output phases (A, B, C), a main power source (320) for providing main input power to the power converter (310), an auxiliary power source (330) for providing auxiliary input power to the power converter (310), and a control system (314) in communication with the power converter (310) and controlling operation of the plurality of power cells, wherein the control system (314) comprises one or more processor(s) (315) configured via computer executable instructions to detect a main input voltage drop of the main power source (320) below a predefined power threshold, disconnect the main power source (320) in response to the main input voltage drop, and enable the auxiliary power source (330) to provide auxiliary input power to the power converter (310) in response to the main input voltage drop.

Abstract: A printed circuit board (PCB) power cell (100) for arranging in a multi-cell power supply (500) includes a housing assembly (102) with a multiple section housing (104, 106), and a PCB assembly (120) positioned within the housing assembly (102), wherein the housing assembly (102) and the PCB assembly (120) are configured to provide an integrated voltage isolation of the power cell (100) which supports an output voltage of the multi-cell power supply (500). Furthermore, a multi-cell power supply (500) including a PCB power cell (100) with isolation is described.

Abstract: A printed circuit board (PCB) power cell (100) for arranging in a multi-cell power supply (500) includes a housing assembly (102) with a multiple section housing (104, 106), and a PCB assembly (120) positioned within the housing assembly (102), wherein the housing assembly (102) and the PCB assembly (120) are configured to provide an integrated voltage isolation of the power cell (100) which supports an output voltage of the multi-cell power supply (500). Furthermore, a multi-cell power supply (500) including a PCB power cell (100) with isolation is described.

Abstract: A printed circuit board power cell having a printed circuit board including a DC bus disposed within the printed circuit board. The printed circuit board power cell includes a plurality of capacitors connected to the DC bus, a three-phase AC input disposed on the printed circuit board and a single-phase AC output disposed on the printed circuit board. The printed circuit board power cell also includes a power module connected to the DC bus, the three-phase AC input and the single-phase AC output, wherein the power module receives three phase AC input power via the three-phase AC input and responsively outputs a single-phase AC power via the single-phase AC output.

Abstract: A system for delivering power to an offshore load is disclosed. The system may include an on-land source of three-phase power, an on-land AC-to-DC power conversion module, a DC transmission line, and an offshore DC-to-AC power inverter. The on-land AC-to-DC power conversion module may be configured to convert the three-phase power to DC power. The DC transmission line may have a source end and a load end, where the source end is configured to receive DC power from the on-land AC-to-DC power conversion module. The offshore DC-to-AC power inverter may be configured to receive DC power from the DC transmission line, convert the DC power to three-phase AC power, and deliver the three-phase AC power to an offshore load.

Abstract: Apparatus and methods in accordance with this invention provide a multi-cell power supply for receiving power from a source and delivering power at an output terminal to a load. The multi-cell power supply includes a first power cell coupled to the source, and a first current sensor circuit. The first power cell provides a first output current, and includes a first output terminal coupled to a reference node of the multi-cell power supply, and a second output terminal coupled to the output terminal. The first current sensor circuit includes a first current sensor and a power supply. The first current sensor is coupled to the first output terminal of the first power cell, and measures the first output current. The power supply is coupled to either the reference node or a floating ground node of the first power cell, and provides power to the first current sensor.

Abstract: Apparatus and methods in accordance with this invention provide a multi-cell power supply for receiving power from a source and delivering power at an output terminal to a load. The multi-cell power supply includes a first power cell coupled to the source, and a first current sensor circuit. The first power cell provides a first output current, and includes a first output terminal coupled to a reference node of the multi-cell power supply, and a second output terminal coupled to the output terminal. The first current sensor circuit includes a first current sensor and a power supply. The first current sensor is coupled to the first output terminal of the first power cell, and measures the first output current. The power supply is coupled to either the reference node or a floating ground node of the first power cell, and provides power to the first current sensor.

Abstract: Apparatus and methods in accordance with this invention provide a multi-cell power supply for receiving power from a source and delivering power at an output terminal to a load. The multi-cell power supply includes a first power cell coupled to the source, and a first current sensor circuit. The first power cell provides a first output current, and includes a first output terminal coupled to a reference node of the multi-cell power supply, and a second output terminal coupled to the output terminal. The first current sensor circuit includes a first current sensor and a power supply. The first current sensor is coupled to the first output terminal of the first power cell, and measures the first output current. The power supply is coupled to either the reference node or a floating ground node of the first power cell, and provides power to the first current sensor.

Abstract: A system for delivering power to an offshore load is disclosed. The system may include an on-land source of three-phase power, an on-land AC-to-DC power conversion module, a DC transmission line, and an offshore DC-to-AC power inverter. The on-land AC-to-DC power conversion module may be configured to convert the three-phase power to DC power. The DC transmission line may have a source end and a load end, where the source end is configured to receive DC power from the on-land AC-to-DC power conversion module. The offshore DC-to-AC power inverter may be configured to receive DC power from the DC transmission line, convert the DC power to three-phase AC power, and deliver the three-phase AC power to an offshore load.

Abstract: A method for designing a transformer using three secondary winding phase shift angles and a minimized core cross-sections. The method includes receiving an indication of an acceptable level of total harmonic distortion (THD) for the transformer, identifying a desired number of secondary windings per output phase of the transformer, simulating performance of various models for the transformer various potential phase shift angles, wherein each of the various models includes a set of phase shift angles for the secondary windings of the transformer. The method further includes identifying, based on the simulation, a transformer model that both has no more than three unique phase shift angles in the set and exhibits a primary side THD that is within the acceptable level, identifying an optimized core cross-sections, and reporting the identified transformer model having the three unique phase shift angle and the optimized core cross-sections.

Abstract: A method of reducing switching losses in a power supply includes the steps of advancing the output voltage of a first pole of a power cell by a first angle, retarding the output voltage of a second pole of the power cell by a second angle, and producing a combined output voltage of the power cell equal to a positive pulse of a duration angle equal to the sum of the first angle and the second angle for a first half of a switching cycle of the power cell, and equal to a negative pulse of a duration angle equal to the sum of the first angle and the second angle for a second half of the switching cycle of the power cell.

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 method for designing a transformer using three secondary winding phase shift angles and a minimized core cross-sections. The method includes receiving an indication of an acceptable level of total harmonic distortion (THD) for the transformer, identifying a desired number of secondary windings per output phase of the transformer, simulating performance of various models for the transformer various potential phase shift angles, wherein each of the various models includes a set of phase shift angles for the secondary windings of the transformer. The method further includes identifying, based on the simulation, a transformer model that both has no more than three unique phase shift angles in the set and exhibits a primary side THD that is within the acceptable level, identifying an optimized core cross-sections, and reporting the identified transformer model having the three unique phase shift angle and the optimized core cross-sections.

Abstract: A method of reducing switching losses in a power supply includes the steps of advancing the output voltage of a first pole of a power cell by a first angle, retarding the output voltage of a second pole of the power cell by a second angle, and producing a combined output voltage of the power cell equal to a positive pulse of a duration angle equal to the sum of the first angle and the second angle for a first half of a switching cycle of the power cell, and equal to a negative pulse of a duration angle equal to the sum of the first angle and the second angle for a second half of the switching cycle of the power cell.