Abstract: A method includes performing a test for transformer rectifier unit (TRU) backfeed protection by removing AC power supplied to the TRU but keeping the TRU contactor closed for a first predetermined span of time. The method includes observing the TRU for a second predetermined span of time. The method includes determining if the contactor opens during the second span of time, that a TRU backfeed protection is functional and passes the test, and determining if the contactor does not open during the second span of time, that the TRU backfeed protection has failed the test.

Abstract: A system includes a first AC bus configured to supply power from a first AC power source. A second AC bus is configured to supply power from a second AC power source. A first transformer rectifier unit (TRU) connects a first DC bus to the first AC bus through a first TRU contactor (TRUC). A second TRU connects a second DC bus to the second AC bus through a second TRUC. A ram air turbine (RAT) automatic deployment controller is operatively connected to the first TRUC and to the second TRUC to automatically deploy a RAT based on the combined status of the first TRUC and the second TRUC.

Abstract: In accordance with at least one aspect of this disclosure, a controller for an aircraft electrical system includes, a software safe module. In embodiments, the software safe module can be configured to determine whether there was a sudden power failure upon controller initialization, and cause operation of the controller in a software safe mode if there was a sudden power failure such that manual intervention is required to leave the software safe mode to prevent repetitive power failure of the controller.

Abstract: A closing mechanism controller includes contactor operating logic that generates a software or firmware based closing mechanism command signal. The controller also includes hardware interlock circuitry that generates an interlock signal, the hardware interlock circuity being configured to compare an interlock signal to the software based closing mechanism command signal and to provide an enable signal to the closing mechanism when the interlock signal matches the closing mechanism command signal.

Abstract: A system includes a transformer rectifier unit (TRU) including a backfeed sense module. A contactor is operatively connected to the TRU for selectively supplying DC power to a DC bus from the TRU with the contactor closed and isolating the DC bus from the TRU with the contactor opened. A contactor driver is operatively connected to receive a signal from the backfeed sense module and to control opening and closing of the contactor based on the signal. The contactor driver is configured to open the contactor upon receipt of the signal indicative of backfeed detected in the TRU.

Abstract: A system includes a first AC bus configured to supply power from a first generator. A second AC bus is configured to supply power from a second generator. An AC essential bus tie contactor (AETC) selectively connects between an AC essential bus and the first and second AC busses. An AETC controller is connected to switch the AETC between a first state connecting the AC essential bus to the first AC bus and a second state connecting the AC essential bus to the second AC bus. A sensor system is configured to detect at least one of delta current and overcurrent in the AC essential bus and in at least one of the first AC bus and the second AC bus. The sensor system is operatively connected to the AETC controller for switching the AETC between the first state and the second state based on input from the sensor system.

Abstract: In accordance with at least one aspect of this disclosure, a controller for an aircraft electrical system includes, a software safe module. In embodiments, the software safe module can be configured to determine whether there was a sudden power failure upon controller initialization, and cause operation of the controller in a software safe mode if there was a sudden power failure such that manual intervention is required to leave the software safe mode to prevent repetitive power failure of the controller.

Abstract: A system includes a first AC bus configured to supply power from a first generator. A first generator line contactor (GLC) selectively connects the first AC bus to the first generator. A second AC bus is configured to supply power from a second generator. A second GLC selectively connecting the second AC bus to the second generator. An auxiliary generator line contactor (ALC) is connected to selectively supply power to the first and second AC buses from an auxiliary generator. A first bus tie contactor (BTC) electrically connects between the first GLC and the ALC. A second BTC electrically connects between the ALC and the second GLC. A ram air turbine (RAT) automatic deployment controller is operatively connected to automatically deploy a RAT based on the combined status of the first GLC, the second GLC, the ALC, the first BTC, and the second BTC.

Abstract: A system includes a first AC bus configured to supply power from a first AC power source. A second AC bus is configured to supply power from a second AC power source. A first transformer rectifier unit (TRU) connects a first DC bus to the first AC bus through a first TRU contactor (TRUC). A second TRU connects a second DC bus to the second AC bus through a second TRUC. A first voltage sensor is connected to sense voltage of the first DC bus. A second voltage sensor is connected to sense voltage of the second DC bus. A ram air turbine (RAT) automatic deployment controller is operatively connected to the first voltage sensor and to the second voltage sensor to automatically deploy a RAT based on the combined status of the first voltage sensor and the second voltage sensor.

Abstract: A system includes a first AC bus configured to supply power from a first AC power source. A second AC bus is configured to supply power from a second AC power source. A first transformer rectifier unit (TRU) connects a first DC bus to the first AC bus through a first TRU contactor (TRUC). A second TRU connects a second DC bus to the second AC bus through a second TRUC. A ram air turbine (RAT) automatic deployment controller is operatively connected to the first TRUC and to the second TRUC to automatically deploy a RAT based on the combined status of the first TRUC and the second TRUC.

Abstract: A system includes a first AC bus configured to supply power from a first generator. A first generator line contactor (GLC) selectively connects the first AC bus to the first generator. A second AC bus is configured to supply power from a second generator. A second GLC selectively connecting the second AC bus to the second generator. An auxiliary generator line contactor (ALC) is connected to selectively supply power to the first and second AC buses from an auxiliary generator. A first bus tie contactor (BTC) electrically connects between the first GLC and the ALC. A second BTC electrically connects between the ALC and the second GLC. A ram air turbine (RAT) automatic deployment controller is operatively connected to automatically deploy a RAT based on the combined status of the first GLC, the second GLC, the ALC, the first BTC, and the second BTC.

Abstract: A system includes a first AC bus configured to supply power from a first AC power source. A second AC bus is configured to supply power from a second AC power source. A first transformer rectifier unit (TRU) connects a first DC bus to the first AC bus through a first TRU contactor (TRUC). A second TRU connects a second DC bus to the second AC bus through a second TRUC. A first voltage sensor is connected to sense voltage of the first DC bus. A second voltage sensor is connected to sense voltage of the second DC bus. A ram air turbine (RAT) automatic deployment controller is operatively connected to the first voltage sensor and to the second voltage sensor to automatically deploy a RAT based on the combined status of the first voltage sensor and the second voltage sensor.

Abstract: A system includes a first AC bus configured to supply power from a first generator. A first generator line contactor (GLC) selectively connects the first AC bus to the first generator. A second AC bus is configured to supply power from a second generator. A second GLC selectively connecting the second AC bus to the second generator. An auxiliary generator line contactor (ALC) is connected to selectively supply power to the first and second AC buses from an auxiliary generator. A first bus tie contactor (BTC) electrically connects between the first GLC and the ALC. A second BTC electrically connects between the ALC and the second GLC. A ram air turbine (RAT) automatic deployment controller is operatively connected to automatically deploy a RAT based on the combined status of the first GLC, the second GLC, the ALC, the first BTC, and the second BTC.

Abstract: A system includes a first AC bus configured to supply power from a first generator. A second AC bus is configured to supply power from a second generator. An AC essential bus tie contactor (AETC) selectively connects between an AC essential bus and the first and second AC busses. An AETC controller is connected to switch the AETC between a first state connecting the AC essential bus to the first AC bus and a second state connecting the AC essential bus to the second AC bus. A sensor system is configured to detect at least one of delta current and overcurrent in the AC essential bus and in at least one of the first AC bus and the second AC bus. The sensor system is operatively connected to the AETC controller for switching the AETC between the first state and the second state based on input from the sensor system.

Abstract: A system includes a first AC bus configured to supply power from a first generator. A first generator line contactor (GLC) selectively connects the first AC bus to the first generator. A second AC bus is configured to supply power from a second generator. A second GLC selectively connecting the second AC bus to the second generator. An auxiliary generator line contactor (ALC) is connected to selectively supply power to the first and second AC buses from an auxiliary generator. A first bus tie contactor (BTC) electrically connects between the first GLC and the ALC. A second BTC electrically connects between the ALC and the second GLC. A ram air turbine (RAT) automatic deployment controller is operatively connected to automatically deploy a RAT based on the combined status of the first GLC, the second GLC, the ALC, the first BTC, and the second BTC.

Abstract: A method and system for responding to a fast trip protective element trip in a generator system that re-excites the generator when a fast trip protection element trips and determines whether the generator immediately retrips the fast trip protection element, thereby determining whether a fault is located in the generator or in an attached load. If it is determined that the fault is located in the load, the system re-excites and reconnects the load after disabling the fast trip protection element for a specified period to allow for the load to clear its fault.

Abstract: A method and system for responding to a fast trip protective element trip in a generator system that re-excites the generator when a fast trip protection element trips and determines whether the generator immediately retrips the fast trip protection element, thereby determining whether a fault is located in the generator or in an attached load. If it is determined that the fault is located in the load, the system re-excites and reconnects the load after disabling the fast trip protection element for a specified period to allow for the load to clear its fault.

Abstract: A method of detecting a parallel source condition includes calculating a reactive power, comparing the reactive power to a predetermined threshold, and determining a parallel source condition in response to the reactive power exceeding the predetermined threshold.

Abstract: A method of detecting a parallel source condition includes calculating a reactive power, comparing the reactive power to a predetermined threshold, and determining a parallel source condition in response to the reactive power exceeding the predetermined threshold.