Solid state circuit breaker technology can enhance existing arc fault detection technology by providing a higher tolerance to nuisance tripping and by providing an opportunity to maintain some reduced level of control in the event of an electrical fault. By the appropriate control of power MOSFETs, power may be quickly removed upon the detection of an arc and quickly restored upon the extinction of the arc or to test if the arc has indeed been extinguished. This allows the use of sensitive detection thresholds, and, in an actual fault condition, may allow an aircraft to maintain enough control to complete a mission or to safely land. Phase 1 research will examine various arc quenching algorithms in a laboratory testbed. Arcing severity will be characterized through infrared sensors and power will be removed and then restored with varying schedules to examine the conditions under which an arc may be tolerably controlled through solid state switching. The proposed technology represents an augmentation that will be compatible with existing arc fault detection/interruption technologies. While applicable to both DC and AC electrical systems, it will have its greatest impact on DC arc fault control where only the severest of faults are presently detectable.
Benefits: By allowing a higher sensitivity fault detection threshold to be used, the proposed research enhances sensitivity for arc fault interrupter circuits, increasing the safety they can provide to both commercial and military aircraft. Since aircraft are routinely maintained in service beyond their intended design life, this represents an important addition to the state-of-the-art and a mature technology should enjoy wide acceptance in both markets. In the commercial nonaviation market, arc fault interrupters are presently mandated in new construction in the U.S. (market potential of over 4 million units per year), have been mandated for air conditioners beginning in 2004 (5.7 million units per year) and will see expanded use in the electric and hybrid electric vehicle markets.
Keywords: arc fault, wire insulation failure, self-resetting breaker, DC arc fault, circuit protection technology, mission critical operation, aged aircraft
