Protection of Lightning Indirect Effect for Power Supply System for Flight Test Equipment of C919 Airplane

In this paper, lightning indirect effect analysis and protection research on power supply system of C919 test equipment are carried out. The requirements and process of lightning indirect effect protection in power supply system of test equipment and the corresponding lightning test levels are determined. Analyzing the response of the system during pulse injection of different test levels, comparing with the response of the system under normal operation and device tolerance, it is found that lightning pulse impact the system seriously, causing surge peak, seriously affecting the normal work of the system. The interface protection circuit of the system is designed by using the transient suppression device. The results show that the transient voltage suppression diode (TVS) and voltage sensitive resistor (MOV) in parallel between the power supply and the system equipment, together with the series inductance, can effectively suppress the surge spike caused by lightning pulse, keeping all signals within the normal working range, namely the designed interface protection circuit has a good effect on lightning indirect effect protection of power supply system of test equipment.