The Design And Implementation Of Solid State Power Controller Based On Electric And Thermal Simulation

At present, the sapceraft is moving towards more electric and all electric. The number of airborne equipment is increasing and the power level of the whole vehicle is also promoting, which makes the better aircraft power distribution system is urgently needed. Solid-state power distribution method is gradually replace the conventional and remote control power distribution method as a result of its advantage in light weight, small volume and high degree of automation. As a key component of Solid-state power distribution system, the analysis, design and implementation method of SSPC has a significant value. This paper makes research on the dynamic switching process of SSPC, which establishes corresponding electrical behavioural model, and analyses the power loss in the switching process based on thermal simulation and theoretical evaluation. On this basis, this paper applies FPGA to make hardware and software design of SSPC. Experiment test is performed to prove the function of SSPC. The main work is as follows:First, the dynamic switching process of SSPC is researched based on its behavioural model. On the basis of the principle and structure of SSPC, its dynamic switching process of the electrical behavioural model is established based on the Saber software. From two angles in theory and simulation, analysis on the parameters variation in the switching process of resistive, capacitive and inductive load is executed. The influence of inrush current and transient voltage on the load capacity of SSPC is exploed to obtain more reasonable design parameters, so as to lay a foundation for the design and implementation of SSPC. In addition, the complete digital simulation model is established based on PSIM, which provide basis for the integrated simulation of large power distribution system.Secondly, in order to avoid the over temperature failure caused by inrush current, the loss in steady state and switching process of SSPC power switch is analysed. Based on Saber software, steady-state thermal circuit model and transient thermal circuit model of opening process over the power switch is established to obtain the junction temperature and make comparation with theory calculation, which ensures its temperature rise in a reasonable range. In addition, the ANSYS finite element analysis software is applied to make transient thermal analysis and steady thermal analysis to verify the result of thermal circuit analytical result.Finally, on the basis of electrical and thermal simulation, hardware and software of SSPC which is 28 VDC and 2A is designed based on FPGA. Then this paper applyes the C# to write man-machine interface. After that, all kinds of experiment test of SSPC function is executed such as inverse time overcurrent protection curve, switch control, load condition monitoring and so on. The opening time is debugged to ensure that SSPC has adequate load capacity.This research has some theoretical significance and engineering value on the intelligent development of SSPC. Its electrical and thermal simulation method ca n be applied to analysis and design of more powerful and channels SSPCs.