Matching Design Method of Over-Voltage Protection for Civil Aircraft Main Generation System

With the development of aircraft electrical technology, the constant frequency power generation system on the aircraft has been gradually replaced by the variable frequency power generation system. The application of the variable frequency generator(VFG) makes the design of the civil aircraft main generation system(MGS) obsolete the original constant speed device(CSD) and reduce the system weight. However, working in the wide speed and frequency range intensifies the output variation of the VFG, which increases the difficulty of designing the voltage regulator and excitation module in GCU. Over-voltage fault of power generation system could cause hug e dam age to electrical equipment, not only directly affect the safety of aircraft flight, but also cause significant loss of aircraft reliability and economy. This paper provides a matching design method of over-voltage protection for civil aircraft MGS, which improves the safety design of MGS and reduces the time delay compared to traditional software-based method. In this paper, the importance and principle of over-voltage protection in MGS are introduced. Then the realization logic and matching design principle of over-voltage protection in Generator Control U nit(GCU) and over-voltage Protection Unit(OPU) are introduced respectively. In addition, the matching design method of over-voltage protection is expounded, and the performance simulation of system over-voltage protection is carried out by Simulink, which supports the correctness and rationality of this method.