高空飞艇推进系统参数匹配设计

Simulating Parameter Matching for Propulsion System of High Altitude Airship

进行临近空间飞艇推进系统动态性能仿真可以预先调整部件参数,优化推进系统效率,减小太阳电池和锂电池重量。利用Matlab/Simulink建模仿真工具,通过对稀土永磁无刷直流电机多个独立功能模块的建立和组合,构建了基于PID以及PI控制的转速、电流双闭环串级控制电机仿真模型;根据螺旋桨的运动方程建立了螺旋桨的动态仿真模型。按照电机和螺旋桨的扭矩、转速匹配关系对各仿真模块进行协同化处理。利用集成化仿真模型,进行推进系统各部件参数匹配。得出推进系统功率30 kW时不同桨径推进系统的动态响应特性以及不同高度下最佳减速比,得出了6.8 m桨径推进系统的最佳额定工作点及其工作区域。

The dynamic simulation of the performance of the propulsion system of a high-altitude airship can adjust the parameters of the energy-consuming parts in advance, enhance its efficiency and reduce the weights of a solar cell and lithium battery. We use the MATLAB/Simulink and the PID and PI controls to establish the simulation model of the rotational speed and current double-loop serial control motor by building and integrating the multiple independent functional modules of a rare-earth permanent magnet brushless DC motor. We also use the motion e- quation of the propeller of the high-altitude airship to establish its dynamic simulation model. Then we integrate all the simulation modules with the matching between the torque of the DC motor and the rotational speed of the propel- ler. With the integrated simulation modules, we match the parameters of all the parts of the propulsion system. The simulation results, given in Figs. 2 through 6, and their analysis show preliminarily that deceleration ratio of the propulsion system decreases with increasing altitude. Thus we obtain the optimal deceleration ratio of the propulsion system at different altitudes and the dynamic response characteristics of the propulsion system whose propeller has different diameters. We also obtain the optimal rated working point and working area of the propulsion system whose propeller has the diameter of 6. 8 meters.