Aviation Power Failure Diagnosis Improved DS Evidence Theor

Currently, the various systems on the aircraft are more or less loaded with electronic control devices, these advanced electronic control devices are common needs of its power system to provide energy, so the role of aerospace power systems on the plane to play the other systems irreplaceable, apparently also become one of the major systems of the aircraft. A large number of advanced electronic devices are widely used on aircraft to replace the traditional use of hydraulic equipment, which also makes the power system performance and reliability, safety and other standards continue to improve. In reality, the aircraft will be faced with the work under some special circumstances, the harsh environment will make the aircraft a variety of devices seriously affected, such as electromagnetic interference with the normal operation of equipment, rainy weather to equipment caused by moisture on aircraft systems too large, etc., but if the supply source of the device fails, provided the value of the power supply does not meet the safety equipment the normal operation of other systems, which make the equipment either not work or not work properly, or even to a device a serious security threat, if the device is in this power supply under long-term work, which will lead to paralysis of the entire device, which can not continue to operate, often harm will transfer from the power system fault to other system equipment, and even affect flight performance of an aircraft, which can cause the aircraft not working, it takes enormous human and material resources to detect aircraft. The importance of aviation for the power failure and the purpose and significance of the research, which makes aerospace power system fault detection has become a top priority for the whole ground crew of aircraft maintenance work. Advanced fault diagnosis system can very well find hidden faults before aviation power system failures, and sends the test report for the maintenance of professional reference staff to ensure the safe operation of the aircraft, saving manpower and financial resources.Based on the current deepening aviation power failure detection type and DS evidence theory researches, this paper particularity aviation power failure detection, complexity and its own characteristics, difficulty, using a new DS evidence theory in this class of complex fault type fault prediction and determination. Improved DS evidence theory can be a good remedy DS evidence theory in high conflict failure insufficient evidence combination rule. Even if the resulting data to detect very small or extreme environments, the improved DS evidence theory can be well data fusion, to get satisfactory results.In this paper, aviation power system harmonics generated was further discussed. For aircraft AC power system, with the development of aviation technology, aircraft, airborne equipment (aircraft electrical equipment throughout the grid) structure constantly updated, constantly optimize the design, function continue to improve, but to work is a non-linear load. In actual flight, with the changing of airborne equipment, the power factor will vary widely, so the aircraft power system harmonic "pollution" problem has always existed, and harmonic "pollution" increasingly serious impact on the entire supply system. In this paper, the implementation of a new aviation IF DPWMA three-level PWM rectifier, and the high power factor converter, open tube low loss, low current harmonic content, to improve the quality of the aircraft AC grid power supply is of great significance, and its simulation and verification.