Abstract: Described is an independent speed variable frequency generator system that may include a rotor and a stator. The system may further include a pilot generator stage including a magnetic field source positioned on the rotor and a set of pilot multiphase windings positioned on the stator. The system may also include a high frequency transformer stage including a first set of high frequency transformer multiphase windings positioned on the stator and a second set of high frequency transformer multiphase windings positioned on the rotor. The system may also include a main machine stage including a set of main field multiphase windings positioned on the rotor and a set of main armature multiphase windings positioned on the stator, where the second set of high frequency transformer multiphase windings are coupled directly to the set of main field multiphase windings. The system may include a generator control unit.

Abstract: An electric motor apparatus may include a rotor and a stator. The apparatus may include a main field motor stage having a set of stator armature windings positioned on the stator and a set of main field windings positioned on the rotor, where the set of stator armature windings is configured to receive a main multiphase power signal from an alternating current power bus having a first current that causes a first rotating magnetic flux that rotates relative to the stator, where the set of main field windings is configured to receive a secondary multiphase power signal having a second current that causes a second rotating magnetic flux that rotates relative to the rotor, and where a combination of the first rotating magnetic flux and the second rotating magnetic flux causes the rotor to turn at a predetermined reference frequency.

Abstract: A power supply system suitable for use by an aircraft is disclosed. The power system converts power from an unregulated DC power source to multiple AC and DC voltage outputs. The power supply system comprises an interleaved buck converter, and interleaved full-bridge converter, an interleaved inverter, and a control system. In one configuration, the interleaved inverter uses high-voltage DC generated by the interleaved four-bridge converter as its power input to generate a high-voltage AC output.

Abstract: Described is an independent speed variable frequency generator system that may include a rotor and a stator. The system may further include a pilot generator stage including a magnetic field source positioned on the rotor and a set of pilot multiphase windings positioned on the stator. The system may also include a high frequency transformer stage including a first set of high frequency transformer multiphase windings positioned on the stator and a second set of high frequency transformer multiphase windings positioned on the rotor. The system may also include a main machine stage including a set of main field multiphase windings positioned on the rotor and a set of main armature multiphase windings positioned on the stator, where the second set of high frequency transformer multiphase windings are coupled directly to the set of main field multiphase windings. The system may include a generator control unit.

Abstract: A current balancing system, and associated method and computer-readable medium are disclosed herein. The current balancing system comprises a plurality of power inverters, each power inverter included within a respective current loop and configured to generate a corresponding current amount. The current balancing system further comprises a plurality of inverter controllers, each inverter controller associated with a respective one of the plurality of power inverters and configured to receive a reference frame-transformed amount of the corresponding current amount. Each inverter controller is capable of independently controlling the corresponding current amount provided to a load.

Abstract: An alternating current (AC) power distribution system may include an independent speed variable frequency (ISVF) generator configured to generate an AC power signal having a frequency that is independent from a frequency of a prime mover. The system may also include at least one AC load configured to receive the AC power signal without performing a full-distribution-power-rated power conversion. In another embodiment, an AC power distribution system includes a generator configured to generate an AC power signal and an AC motor configured to receive the AC power signal without performing a full-distribution-power-rated power conversion, where the AC motor is configured to rotate at a rotational frequency that is independent from a frequency of the AC power signal.

Abstract: An independent speed variable frequency alternating current (AC) generator apparatus may include a rotor and a stator, the rotor configured to rotate relative to the stator. The apparatus may further include a magnetic field source attached to the rotor and configured to generate a first rotating magnetic field upon rotation of the rotor, where a rotational frequency of the first rotating magnetic field is dependent on a rotational frequency of the rotor. The apparatus may also include a main rotor winding attached to the rotor and configured to generate a second rotating magnetic field upon the rotation of the rotor, where a rotational frequency of the second rotating magnetic field is independent of the rotational frequency of the rotor.

Abstract: An EMI filter network may be used to provide interference filtering for multiple loads (referred to collectively as a dynamic load). In one aspect, the EMI filter network includes electrical switches that establish different configurations or arrangements of passive circuit elements (e.g., inductors and capacitors) where each configuration generates a different filter value. The EMI filter network may be communicatively coupled to a controller which changes the configuration of the EMI filter network using the switches in response to the dynamic load changing operational states. For example, each configuration of the EMI filter network may correspond to one of the operational states of the dynamic load. Thus, as the operational state of the dynamic load changes—e.g., different motors become operational—the controller alters the configuration of the EMI filter network to provide a filter value that corresponds to the current operational state of the dynamic load.

Abstract: A main field circuit of an electrical generator and associated system and method are disclosed. The main field circuit comprises a main field winding configured to conduct a main field current, and a counter-field winding arranged proximate to the main field winding. The main field circuit further comprises a switch element configured to selectively couple at least a portion of the main field current into the counter-field winding to reduce a magnitude of the main field current. Coupling at least a portion of the main field current into the counter-field winding may be performed responsive to one or predefined conditions, such as a predefined load fault condition and enabling a predefined field weakening operation.

Abstract: A system may include a first bus transfer switch configured to open and close connections between a generator control unit, a pilot permanent magnet generator stage of an independent speed variable frequency (ISVF) generator, and an external power source. The system may further include an inverter configured to set a main field winding of the ISVF generator into a motor state. The system may also include a second bus transfer switch configured to open and close a connection between a main armature winding of the ISVF generator, a power distribution bus, and a motor start driver configured to send a current through the main armature winding to generate a magnetic field pattern that causes the rotor to turn, enabling startup of an engine.

Abstract: A method is disclosed for controlling power distribution from a plurality of inverters to one or more loads. The method comprises determining, using one or more computer processors, a plurality of possible combinations of the plurality of inverters to meet load demands corresponding to the one or more loads. Each possible combination of the plurality of possible combinations includes a respective set of one or more inverters of the plurality of inverters. The method further comprises accessing, from a memory coupled with the one or more computer processors, one or more predefined efficiency functions associated with the one or more inverters; selecting, based on the one or more predefined efficiency functions, a combination from the plurality of possible combinations; and transmitting control signals to the set of one or more inverters corresponding to the selected combination to thereby power the one or more loads.

Abstract: In general, certain embodiments of the present disclosure provide methods and systems for determination and assessment of arc flash hazards at an equipment in an electrical power system operative at 400-Hz. According to various embodiments, a method is provided comprising determining an arc current at the equipment and generating an arc flash model based on the determined arc current. The method further comprises determining a value of arc flash incident energy by use of the arc flash model. In some embodiments, an arc flash protection boundary distance and/or a level of Prosomal Protection Equipment (PPE) are further determined by use of the value of arc flash incident energy for the equipment in the 400-Hz electrical power system.

Abstract: A system may include a first bus transfer switch configured to open and close connections between a generator control unit, a pilot permanent magnet generator stage of an independent speed variable frequency (ISVF) generator, and an external power source. The system may further include an inverter configured to set a main field winding of the ISVF generator into a motor state. The system may also include a second bus transfer switch configured to open and close a connection between a main armature winding of the ISVF generator, a power distribution bus, and a motor start driver configured to send a current through the main armature winding to generate a magnetic field pattern that causes the rotor to turn, enabling startup of an engine.

Abstract: An alternating current (AC) power distribution system may include an independent speed variable frequency (ISVF) generator configured to generate an AC power signal having a frequency that is independent from a frequency of a prime mover. The system may also include at least one AC load configured to receive the AC power signal without performing a full-distribution-power-rated power conversion. In another embodiment, an AC power distribution system includes a generator configured to generate an AC power signal and an AC motor configured to receive the AC power signal without performing a full-distribution-power-rated power conversion, where the AC motor is configured to rotate at a rotational frequency that is independent from a frequency of the AC power signal.

Abstract: Systems, methods, and apparatus for secondary windings to modify a permanent magnet (PM) field of a permanent magnet synchronous generator (PMSG) are disclosed. In one or more embodiments, a disclosed system for a PMSG comprises a permanent magnet (PM) of the PMSG to rotate and to generate a permanent magnet field. The system further comprises a plurality of stator primary windings (SPW), of the PMSG, to generate primary currents from the permanent magnet field. Further, the system comprises a plurality of stator secondary windings (SSW), of the PMSG, to draw secondary currents from a power source, and to generate a stator secondary winding magnetic field from the secondary currents. In one or more embodiments, the permanent magnet field and the stator secondary winding magnetic field together create an overall magnetic field for the PMSG.

Abstract: A synchronous machine (100) has a frame (110), a shaft (115), a main section (120), and an exciter section (125). The main section (120) has a stator winding (130) which is mounted on the frame, and a rotor winding (135) which is mounted on the shaft. The exciter section has a transformer (140) and a rectifier (145). The transformer has a primary winding (140A) mounted on the frame and a secondary winding (140B) mounted on the shaft. The rectifier is mounted on the shaft and rectifies an output of the secondary winding to provide a rectified output to the rotor. A control unit (170) provides a high-frequency control signal to the primary winding. This signal is magnetically coupled to the secondary winding, rectified, and then applied to the rotor to control the operation of the synchronous machine.

Abstract: An independent speed variable frequency alternating current (AC) generator apparatus may include a rotor and a stator, the rotor configured to rotate relative to the stator. The apparatus may further include a magnetic field source attached to the rotor and configured to generate a first rotating magnetic field upon rotation of the rotor, where a rotational frequency of the first rotating magnetic field is dependent on a rotational frequency of the rotor. The apparatus may also include a main rotor winding attached to the rotor and configured to generate a second rotating magnetic field upon the rotation of the rotor, where a rotational frequency of the second rotating magnetic field is independent of the rotational frequency of the rotor.

Abstract: A main field circuit of an electrical generator and associated system and method are disclosed. The main field circuit comprises a main field winding configured to conduct a main field current, and a counter-field winding arranged proximate to the main field winding. The main field circuit further comprises a switch element configured to selectively couple at least a portion of the main field current into the counter-field winding to reduce a magnitude of the main field current. Coupling at least a portion of the main field current into the counter-field winding may be performed responsive to one or predefined conditions, such as a predefined load fault condition and enabling a predefined field weakening operation.

Abstract: A programmable alternating current (AC) load in communication with an equipment under test (EUT) is disclosed, where the EUT generates an equipment under test voltage. The programmable AC load includes an active load profiler (ALP) for creating current modulation load profiles that are sent to the EUT. The ALP includes a voltage source inverter, a control module in operative communication with the voltage source inverter of the ALP, and a grid-connected inverter having an AC side and a direct current (DC) side. The AC side of the voltage source inverter is in communication with the EUT for receiving the equipment under test voltage. The control module sends a control duty signal to the voltage source inverter indicating a switching frequency and a duty cycle of the current modulation load profiles.

Abstract: A method and system for controlling power transfer includes the operations of receiving a power transfer value indicating a power level to be transferred either to or from an energy storage sub-system and receiving an input comprising a rotational speed of a rotating mass in the energy storage sub-system. The operations further include calculating a torque value corresponding to the power transfer value based on the rotational speed of the rotating mass and determining whether the torque value exceeds a maximum allowed torque. The operations further include defining an adjusted torque value as the maximum allowed torque value if the torque value exceeds the maximum allowed torque value or defining the adjusted torque value as the torque value if the torque value does not exceed the maximum allowed torque value, and providing the torque value to a direct torque controller for controlling the torque of the rotating mass.