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The More Electric Aircraft (MEA) stands for the direction of aviation development in the new era, and the reliability of power systems on the MEA has attracted widespread attention. Based on the characteristics of MEA power systems, an equivalent method of electrical topology structure is presented in this article, and evaluation method is proposed which shows the reliability of the overall system with the reliability of specific nodes. Firstly, electrical topology structure of a MEA power system is converted into a network node diagram according to the proposed equivalent method. Then, the minimal path sets of specific nodes are obtained by the adjacent matrix algorithm, and the low-order minimal cut sets of disjointed are obtained. After that, the actual failure rate of components is converted to node failure rate, and the reliability of the overall system is evaluated by operational reliability indexes of specific nodes. Finally, taking the MEA A380 as an example, this paper compares and analyzes the reliability of AC loads, DC loads, and key loads to verify the validity and feasibility of the proposed evaluation method. This evaluation system can predict the weak points existing in the MEA power system, as well as providing theoretical support for maintenance schedule.

Large signal stability means that a system can be a transition to a new stable state without losing synchronism after a large disturbance. The large signal stability problem brought by large capacity electrical loads in ac/dc independent power system is prominent, which seriously affects the dynamic security of the system. In view of modeling characteristics of ac/dc system, a generalized state space average large signal modeling method for the ac/dc independent power system in dq-coordinates is proposed. A large signal model of the ac/dc independent power system is constructed, which includes generators, inverter units, rectifying units, and dc/dc converters. The simulation results indicate that the large signal model constructed in this paper can accurately reflect the dynamic characteristics of the system under large disturbances, such as startup and sudden change in load, which is helpful to understand and improve the dynamic performance of the system under large disturbance. Furthermore, with feasibility and effectiveness, the large signal model provides convenience and possibility for the theoretical analysis of large signal stability of ac/dc independent power systems in the future.

In Constant speed constant frequency (CSCF) AC power supply system, generator output constant frequency and constant voltage AC power by connecting engine with constant speed transmission device (CSD). However, CSCF has many disadvantages, such as complex structure, heavy weight, high cost and low energy conversion efficiency. By eliminating CSD in CSCF and taking output voltage and output frequency as feedback quantities, this paper proposes a dual excitation control method to achieve the same effect as CSCF power source. From the perspective of engineering applications, this improved method can greatly reduce the weight of aviation power generation system. It has a simple structure and can cut down the cost of power system operation and maintenance. Simulation results show that the method of dual excitation control presented in this paper is effective, and it also provides a new idea for the improvement in aviation power generation system.