Acronym : arcangel-alpha

the ability to detect and isolate electrical faults is critical to the MEA.

Eaton is the world leader in arc fault protection technologies with over 100 related patents, over

250,000 recorded flight hours with Eaton arc fault protection components. Eaton is the only manufacturer qualified to the SAE AS5692 General Specification for Arc Fault Circuit Breakers.

The conventional 120VAC 400Hz aircraft electrical bus is evolving to a variable frequency system to allow elimination of the complex and heavy constant velocity gearbox generator drives from the engines. While this reduces the weight and

maintenance burdens, it does not improve the ability to efficiently distribute power over the fixed frequency system. New designs from Airbus and Boeing are beginning to implement 230 volt variable frequency AC and 270-540 volt DC electrical power distribution systems to enable the MEA concepts.

The ability of the algorithm design to resist ‘Nuisance tripping’ was planned to be assessed against existing electrical loads.

Arc detection algorithms development was planned using computer based analysis and modelling. The project included the building of Arc fault detection modules to implement the algorithms. These prototype modules were planned to be integrated into a power distribution system.

Finally, the Eaton team planned provided technical support for the field testing and verification of the integrated AFD/switching device solution.

This package involved the setting up of test facilities to enable the production of arcs and capture of the associated characteristics. This work dealt with the capture of information for both High Voltage Alternating Current (HVAC) and High Voltage Direct Current (HVDC) cases. This work was complimented by analytical assessment of some of the test cases for the purpose of developing confidence in modelling methods.

Two types of detection module were produced, one for HVAC and another for HVDC applications. These modules were designed to achieve a Technical Readiness Level 5 (TRL 5) level of development. This provided a “high fidelity” laboratory integration of components within a test bench type of enclosure.

The modules were assessed under test for their response to generated arcs. SAE standard AS5692 was used as the criteria for successful operation of the modules. The resistance of the modules to ‘Nuisance tripping’ is vital. The modules were operated in-line with several available typical aircraft loads to assess the ability of the modules to not react to normal electrical noise.

The validated modules were supplied to the project lead partner. This also included initial commissioning within the new Power Distribution System.

May 2012 Environmental study completed

March 2013 Detection Modules delivered

November 2013 Validation report issued

February 2014 Modules integrated

b) Environmental benefits
The development of 540VDC and 230VAC Arc

Fault Circuit Interruption (AFCI) technology will facilitate the development of an integrated electrical power distribution system by providing the required high voltage switching components with the technology to reduce the incidence and severity of damage, fires, and electrical defects caused by aging wire insulation that risks aircraft/crew safety. The use of these higher voltage systems will potentially reduce the aircraft weight and fuel consumption. By using higher voltages, current can be significantly reduced whilst still providing the same power and significantly reducing the weight of the wiring as smaller gauge wire is used.

The delivered modules are considered to have achieved a TRL5 level of maturity for HVAC and HVDC arc fault detection.