Research On Power Supply And Emergency Switching System For Flight Test Equipment Of C919 Airplane

New airplanes need install many test equipment to test the performance of the airplane and record test data in test flight. The power supply of the test equipment is the key to successful fight test. According to the requirement of different kind of test equipment, the test flight power supply system converter the aircraft electric power to suitable forms and distribute to different area.According to the flight test requirement of C919 airplane, this paper analyzes the supply and switching demand of test equipment, designs the power distribution system layout and the system switching function. Two sets of flight test equipment power supply system is developed. The ontology aircraft power supply of C919 airplane is 115 V 360-800 Hz, however the installed equipment needs two kinds of power supply: 28 V dc for 3 channel which has 4 kinds of working modes according flight states, and 115 V 400Hz for special ac device. In the paper, 28 V output AC/DC converter, 400 Hz output AC/AC converter and model switching device are design in detail and developed with product.The 12 pulse transformer rectifier is developed to realize AC/DC converting. The output power is 7 kW with high power density and high efficiency. A novel asymmetry 12 pulse P type auto-transformer rectifier for 270 dc power supply system is proposed. The novel structure is simple and has no balance reactor. The AC/AC converter with variable frequency input and fix frequency output is implemented by three-phase to single-phase matrix converter, and a novel control strategy is applied which feedback the output weigh composite voltage to improve output control. Finally, model switching device is developed to implement the switch process in Dual- Generator, Single-Generator, Dual-Generator closing and emergency working modes.Power Supply and Emergency Switching System for Flight Test Equipment of C919 102 th Airplane finish designing and debugging, a lot of function experiment are carried out. The results shows the system works stably, and it can supply high quality electric power to test equipment and switch smoothly from four working modes.