【作者】 张勇；

【导师】 张继华；

【作者基本信息】 辽宁工程技术大学 ， 电气工程（专业学位）， 2023， 硕士

【摘要】 受电弓滑板与接触网导线之间的接触电阻是表征弓网系统受流质量的关键参数,因此研究高速大电流条件下接触电阻的影响因素具有重要意义。本文首先建立了弓网系统滑动电接触接触电阻仿真模型,利用滑动电接触接触电阻的实验数据验证了仿真模型的有效性。仿真计算了高速大电流条件下接触压力、滑动速度、接触电流滑板位置和滑板物理性能参数等对接触电阻的影响。仿真结果表明:在高速大电流仿真条件下,弓网接触电阻随静态接触压力的增大而减小,由于材料硬度对表面形变的限制,接触电阻的减小趋势变缓,而波动载荷和波动频率的增大都会使接触状态恶化导致接触电阻略微增大;接触电阻随接触电流的增大而减小,在接触电流超过750A后接触电阻不再随电流的增大而发生变化;滑动速度的增大使接触表面产生更多热量,导致接触状态恶化,接触电阻随滑动速度的增大而快速增大;滑板不同位置的接触电阻也不相同;相同仿真条件下,接触电阻随滑板的电导率、热导率的增大而减小,电导率和热导率直接或间接地影响导体的导电能力,改变接触电阻的大小,当滑板的硬度增大时,接触电阻呈现先快速增加后增加变缓的变化趋势。为了预测高速大电流条件下的接触电阻,建立接触电阻预测模型,引入非线性动态权重因子,基于透镜成像原理的反向学习策略改进北方苍鹰优化算法NGO,通过与北方苍鹰优化算法(NGO)、鲸鱼优化算法(WOA)、粒子群优化算法(PSO)和灰狼优化算法(GWO)的测试比较,证实了改进的NGO算法在各方面的性能均优于上述算法。使用改进的NGO算法结合XGboost算法建立弓网动态接触电阻预测模型,通过Matlab计算结果得到了改进的NGO-XGBoost模型对动态接触电阻的预测结果,预测精度达到96.24%,与传统XGBoost模型的预测结果相比较,明显看出了改进的NGO-XGBoost模型的优越性,为进一步研究弓网系统动态接触电阻提供了新的方法。该论文有图37幅,表11个,参考文献68篇。更多还原

【Abstract】 The contact resistance between the pantograph slide and the contact wire is a key parameter to characterize the current quality of the pantograph-catenary system,Therefore,it is of great significance to study the influencing factors of contact resistance under high-speed and highcurrent conditions.In this paper,a simulation model of sliding electrical contact resistance of pantograph system is first established,and the effectiveness of the simulation model is verified by using the experimental data of sliding electrical contact resistance.The influence of contact pressure,sliding speed,contact current skateboard position and physical performance parameters of skateboard under high-speed and high-current conditions on contact resistance is calculated.The simulation results show that under the simulation conditions of high speed and high current,the contact resistance of the pantograph decreases with the increase of static contact pressure,and the decrease trend of contact resistance slows down due to the limitation of material hardness on surface deformation,while the increase of fluctuating load and fluctuation frequency will deteriorate the contact state and lead to a slight increase in contact resistance.The contact resistance decreases with the increase of the contact current,and the contact resistance no longer changes with the increase of the current after the contact current exceeds 750A;The increase of sliding speed causes more heat to generate on the contact surface,resulting in deterioration of the contact state,and the contact resistance increases rapidly with the increase of sliding speed;The contact resistance at different positions of the skateboard is also different;Under the same simulation conditions,the contact resistance decreases with the increase of conductivity and thermal conductivity of the skateboard,conductivity and thermal conductivity directly or indirectly affect the conductivity of the conductor,change the size of the contact resistance,when the hardness of the skateboard increases,the contact resistance shows a trend of rapid increase first and then increase slowdown.In order to predict the contact resistance under high-speed and high-current conditions,a contact resistance prediction model is established,a nonlinear dynamic weight factor is introduced,and the reverse learning strategy based on the lens imaging principle improves the northern goshawk optimization algorithm NGO,and the test comparison with the northern goshawk optimization algorithm(NGO),whale optimization algorithm(WOA),particle swarm optimization algorithm(PSO)and gray wolf optimization algorithm(GWO)confirms that the improved NGO algorithm is superior to the original NGO algorithm in all aspects.The prediction model of dynamic contact resistance of pantograph mesh is established by using the improved NGO algorithm combined with the XGboost algorithm,and the prediction results of the improved NGO-XGBoost model on the dynamic contact resistance are obtained through the Matlab calculation results,and the prediction accuracy reaches 96.24%,which obviously shows the superiority of the improved NGO-XGBoost model compared with the prediction results of the traditional XGBoost model,and provides a new method for further research on the dynamic contact resistance of the pantograph system.The paper has 37 figures,11 tables,and 68 references.更多还原