Research On Characteristics Of Electrical Loads Of More-Electric-Aircraft

With the rapid development of aviation technology, More-Electric Aircraft(MEA) has become an inevitable trend. So, it is very important to explore the electrical system of aircraft with high efficiency and high reliability. This paper mainly studied the characteristics of electrical loads in the electrical system of MEA. It made a study of control strategies and a stability analysis for the typical nonlinear loads. Then it realized the display of the electrical parameters of each part to reduced the influence of the characteristic of electrical energy feedback on the stability of the power grid and earn a better performance of the system.This paper introduced the power supply of MEA and redundant power distribution system according to B787. It classified the electrical loads and then analyzed characteristics of all kinds of loads. The study focused on the characteristics of constant power of the nonlinear loads and established a small signal model of Constant Power Load(CPL). It discussed the stability of the parallel system with CPL and Constant Voltage Load(CVL) by using the Lyapunov second method in the large signal perturbation state. The stability of the synchronous generator with CPL was analyzed by using the state space averaging theory and the DQ axis transform theory. It derived the transfer function, established the precise state equation and got stable operating conditions finally. Models of typical CPL were built to get each single stable system, such as DC converters, static converters and radar pulse loads. The principle of choosing topology and control strategy was explained. The correctness of the theoretical design was verified by the simulation of parallel system.The stability and dynamic characteristics of the system were compared by the simulation test under different measures in order to obtain methods for improving the stability of power grid.ANSOFT SIMPLORER, a multi-field and high-performance simulation software, was used in conjunction with MATLAB to carry on the simulation analysis to electric circuits. The GUI of MATLAB was used to design the monitoring terminal and display electrical parameters of loads and statistical power. This helps to protect aircraft's automatic power system in time when the power grid is in trouble. This co-simulation technology will greatly improve the accuracy of the simulation and the credibility. It can shorten the design cycle and time of products to reduce costs.