Review and Prospect of Fault Diagnosis Method of Satellite Power System Based on Machine Learning
Aiming at the complex characteristics of the current satellite power supply system and the mass data produced in its operation process, an integrated fault diagnosis method based on deep learning and expert diagnosis was proposed. The deep learning has the capability to deeply investigate the incidence relation between abnormal data and faults, and the has the superiority of making full use of domain experts' experience and simulating their reasoning process expert system es for solutions. The combination of them both can improve the reliability of satellite power failure diagnosis and provide a new way of thinking for the development of satellite power failure diagnosis method. Introduction At present, all countries in the world have strengthened their support for space science and technology. Aerospace science and technology level can reflect the national comprehensive power. Due to complex space environments, it is inevitably for the satellite to meet faults during operation, which will seriously affect safe operations of the satellite. The power supply system plays an important role in the operation of the satellite because it can supply power to the satellite platform and the effective load. Some scholars have calculated more than 500 faults during the in orbit operation of the satellite, 55% of which were propulsion system and control system faults, 14% of which were power system failures, and the fault rate of the power system ranked the second among satellite faults[1,2,3] Whether the power system works normally or not is directly related to normal operations of the satellite. Therefore, it is of great significance to research fault diagnosis of the satellite. Fault Analysis of Satellite Power System Division of Power System Working States The work of the power system can be divided into the lighting period and ground shadow period. (1) During the lighting period, the energy generated by the solar battery array can meet normal operations of the satellite. In this case, it is necessary to test whether the battery has a charging demand. Charge the battery if it needs to be charged. If it does not need to be charged, remaining current shall be distributed. During this period, the shunt regulator continues to work and the charging regulator is in an uncertain state, but the discharge regulator does not work. (2) In the earth shadow period, the battery supplies power to the satellite. At this stage, the solar array, shunt regulation machine and charging regulator do not work, but the discharge regulators work. Classification of Power System Faults Faults of solar array battery often occur in the following positions: cables, power distribution switches, solar arrays, power controllers, batteries and so on. According to the study [4] on orbit faults of the satellite mainly occur on the solar array, as shown in Figure 1.