Abstract: A system includes a permanent magnet (PM) machine including a first phase winding and a second phase winding and a permanent magnet configured to rotate relative to the first and second phase windings. The first phase winding has a main leg and a return leg extending from the first phase winding. The second phase winding has a main leg and a return leg extending from the second phase winding. A return switch unit is operatively connected to the return legs of the first phase winding and the second phase winding. The return switch unit includes a switch configured to connect the return legs of the first phase and second phase to a neutral node in the return switch unit in a normal state, and to disconnect the return legs of the first and second phase windings from the neutral node in a fault protection state.

Abstract: A system includes a transformer rectifier unit (TRU) having three inputs, a first AC bus configured to supply power to a first of the three inputs, a second AC bus configured to supply power to a second of the three inputs, and a third AC bus configured to supply power to a third of the three inputs. The system includes a power quality sense device electrically connected to each of the first, second and third AC busses. The system includes an electrically held contactor electrically connected between the TRU and the power quality sense device. The electrically held contactor is configured and adapted to be switched ON or OFF depending on whether the power quality sense device is energized or de-energized.

Abstract: Systems for parallel excitation for a synchronous machine are provided. Aspects include a rectification circuit coupled to an output of a permanent magnet generator, and an excitation winding connected to an output of the rectification circuit, a direct current (DC) power source connected between an output of the rectification circuit and the excitation winding, wherein the excitation winding supplies an excitation voltage to an excitation armature in a main generator during a during a plurality of operational modes, wherein the plurality of operational modes comprise a startup mode and a generator mode, wherein a DC excitation voltage is provided to the excitation windings by the DC power source during the startup mode, and wherein the DC excitation voltage is provided to the excitation windings by the rectification circuit during the generator mode.

Abstract: A high voltage DC (HVDC) system can include a generator configured to output alternating current (AC), a rectifier connected to the generator via AC phase lines, the rectifier configured to convert the AC to DC to output the DC to DC feeder lines, and a crowbar system. The crowbar system can include a switch module operatively connected to the AC phase lines to prevent AC from flowing to the rectifier in a cutoff state. The crowbar system can be configured to determine whether at least one cutoff condition exists. The at least one cutoff condition can be or include one or more of a DC overcurrent downstream of the rectifier, a DC overvoltage downstream of the rectifier, an AC overcurrent from the generator, or an arc fault. The crowbar system can be configured to control the switch module to the cutoff state if the at least one cutoff condition exists.

Abstract: A ram air turbine (RAT) system can include a generator configured to be turned by a RAT and to output an alternating current (AC) power, a generator control unit (GCU) configured to control an output of the generator, a rectifying module configured to rectify the AC power into a direct current (DC) power, and a DC load configured to receive the DC power from the rectifying module. The DC load can be operatively connected to the GCU to provide feedback from the DC load to the GCU. The GCU can be configured to control the output of the generator as a function of the feedback to prevent stalling of the RAT and/or doorbelling current and/or voltage in the system caused by disconnecting the generator from the DC load.

Abstract: Systems for a cascaded multiple feedback generator controller are provided. Aspects include a direct current (DC) power supply comprising a generator and a rectifier circuit connected to a load, a first voltage sensing device coupled to a first point of regulation, a second voltage sensing device coupled to a second point of regulation, a generator controller configured to receive a first voltage signal from the first voltage sensing device, receive a second voltage signal from the second voltage sensing device, determine an adjustment for the generator, the adjustment comprising a transient performance response and a voltage droop response, wherein the transient performance response is determined based on the first voltage signal, and wherein the voltage droop response is determined based on the second voltage signal, and operate the generator based on the adjustment for the generator.

Abstract: A system includes a transformer rectifier unit (TRU) having three inputs, a first AC bus configured to supply power to a first of the three inputs, a second AC bus configured to supply power to a second of the three inputs, and a third AC bus configured to supply power to a third of the three inputs. The system includes a power quality sense device electrically connected to each of the first, second and third AC busses. The system includes an electrically held contactor electrically connected between the TRU and the power quality sense device. The electrically held contactor is configured and adapted to be switched ON or OFF depending on whether the power quality sense device is energized or de-energized.

Abstract: A system includes a transformer rectifier unit (TRU) having three inputs, a first AC bus configured to supply power to a first of the three inputs, a second AC bus configured to supply power to a second of the three inputs, and a third AC bus configured to supply power to a third of the three inputs. The system includes a power quality sense device electrically connected to each of the first, second and third AC busses. The system includes an electrically held contactor electrically connected between the TRU and the power quality sense device. The electrically held contactor is configured and adapted to be switched ON or OFF depending on whether the power quality sense device is energized or de-energized.

Abstract: A system and method for differential protection is provided. Aspects includes determining a first current value associated with a first current transformer coupled to a first location in a differential protection zone, the first current transformer having a first transformer ratio, determining a second current value associated with a second current transformer coupled to a second location in the differential protection zone, the second current transformer having a second transformer ratio, and determining, by a controller, a type of fault associated with the differential protection zone based on the first current value and the second current value.

Abstract: A system includes a transformer rectifier unit (TRU) having three inputs, a first AC bus configured to supply power to a first of the three inputs, a second AC bus configured to supply power to a second of the three inputs, and a third AC bus configured to supply power to a third of the three inputs. The system includes a power quality sense device electrically connected to each of the first, second and third AC busses. The system includes an electrically held contactor electrically connected between the TRU and the power quality sense device. The electrically held contactor is configured and adapted to be switched ON or OFF depending on whether the power quality sense device is energized or de-energized.

Abstract: A ram air turbine (RAT) system can include a generator configured to be turned by a RAT and to output an alternating current (AC) power, a generator control unit (GCU) configured to control an output of the generator, a rectifying module configured to rectify the AC power into a direct current (DC) power, and a DC load configured to receive the DC power from the rectifying module. The DC load can be operatively connected to the GCU to provide feedback from the DC load to the GCU. The GCU can be configured to control the output of the generator as a function of the feedback to prevent stalling of the RAT and/or doorbelling current and/or voltage in the system caused by disconnecting the generator from the DC load.

Abstract: An example power distribution system includes a relay moveable to a position that holds at least one contactor closed. The relay is moved to the position in response to an alternate source powering a power distribution system rather than a main source powering the power distribution system.

Abstract: A controller is employed in conjunction with an electrical power distribution system (EPDS). The controller includes at least a first input for receiving DC power from a DC power bus and a power supply circuit connected to the first input to provide operational power to the controller. The controller further includes a power interrupt bridge circuit that monitors the voltage provided of the first input. In response to the monitored voltage being less than a threshold value, the power interrupt bridge circuit supplies power to the power supply circuit from a DC emergency source for a defined time period.

Abstract: An electrical system architecture has at least two sources of electrical power, each delivering power to an individual AC bus. The individual AC buses are connected by a tie bus. A first source of electric power delivers power into a first AC bus, and the first AC bus delivers power to a first set of users. A supply current sensor is between the first source of power and the first AC bus. A tie bus output sensor senses output power from the AC bus being delivered onto the tie bus. A plurality of user output current sensors sense current passing to each of the plurality of users. A control is operable to compare a sensed current in the supply current sensor, and sum the current in the tie bus output sensor, and the plurality of user output sensors. If the sum of the output sensors differs by more than a predetermined amount from the current sensed by the supply sensor, the control identifies a fault. The first AC bus is then disconnected from the tie bus.

Abstract: A system comprising a transformer rectifier unit (TRU) and a protection module operatively connected to an alternating current (AC) bus and configured to receive an AC power signal from the AC bus. The protection module is configured to monitor one or more parameters of the AC power signal and is configured to control a protection module output in response to the one or more parameters of the AC power signal. The protection module output is operatively connected to the TRU, which is configured to generate a direct current (DC) output signal. An associated method is also disclosed.

Abstract: A ram air turbine deployment module includes a normal power module that determines if normal power from an aircraft is available, an air-ground module that determines if the aircraft is off the ground, a ground-maintenance module that determines if the aircraft is presently having maintenance preformed, and decision logic that provides an output to a ram air turbine that deploys the ram air turbine if normal power from the aircraft is not available, the aircraft is off the ground, and the aircraft is not presently having maintenance performed.

Abstract: An electrical system architecture has at least two sources of electrical power, each delivering power to an individual AC bus. The individual AC buses are connected by a tie bus. A first source of electric power delivers power into a first AC bus, and the first AC bus delivers power to a first set of users. A supply current sensor is between the first source of power and the first AC bus. A tie bus output sensor senses output power from the AC bus being delivered onto the tie bus. A plurality of user output current sensors sense current passing to each of the plurality of users. A control is operable to compare a sensed current in the supply current sensor, and sum the current in the tie bus output sensor, and the plurality of user output sensors. If the sum of the output sensors differs by more than a predetermined amount from the current sensed by the supply sensor, the control identifies a fault. The first AC bus is then disconnected from the tie bus.

Abstract: An example power distribution system includes a relay moveable to a position that holds at least one contactor closed. The relay is moved to the position in response to an alternate source powering a power distribution system rather than a main source powering the power distribution system.

Abstract: A controller is employed in conjunction with an electrical power distribution system (EPDS). The controller includes at least a first input for receiving DC power from a DC power bus and a power supply circuit connected to the first input to provide operational power to the controller. The controller further includes a power interrupt bridge circuit that monitors the voltage provided of the first input. In response to the monitored voltage being less than a threshold value, the power interrupt bridge circuit supplies power to the power supply circuit from a DC emergency source for a defined time period.