基于BP神经网络和遗传算法的简单链型悬挂接触网结构优化

Structural Optimization of Simple Catenary Based on BP Neural Network and Genetic Algorithm

受电弓和接触网之间的接触力标准差是评价弓网受流质量的重要指标。为了优化弓网受流质量,建立经EN50318标准和已有文献仿真结果验证的弓网耦合仿真模型。采用中心复合设计方法设计输入-吊弦间距和接触线预弛度参数试验表,然后根据该试验表调整弓网耦合仿真模型,并进行仿真,提取输出-接触力标准差。采用BP神经网络(Backpropagationneural network,BPNN)建立输入和输出之间的关系模型,模型预测精度达95.50%。然后,采用遗传算法(Genetic algorithm,GA)搜寻该BP神经网络模型的最小接触力标准差及所对应的最优输入参数组合。优化结果表明,BPNN-GA优化方法能显著降低弓网接触力标准差,从而提高弓网受流质量。最后,通过将优化后的接触网与原始接触网不同速度下接触力标准差进行比较,验证了优化接触网的弓网受流改善效果。经优化后的接触网可为实际接触网设计、施工、维修提供指导。

The standard deviation of contact force(CFSD)between pantograph and catenary is an important index to evaluate the current collection quality of pantograph and catenary.In order to optimize the pantograph catenary current collection quality,a pantograph-catenary coupling simulation model verified by EN 50318 standard and the simulation results in the existing literature is established.The central composite design method is used to design the test table of input parameters(dropper spacing and contact wire pre-sag).The pantograph catenary coupling simulation model is carried out after modifying the model according to the test table.Based on this,the output parameter(CFSD)is obtained.Back propagation neural network(BPNN)is used to establish the relationship model between input and output parameter,and the prediction accuracy of the model is proved to be 95.50%.Then,genetic algorithm(GA)is used to search the minimum standard deviation of contact force and the corresponding optimal combination of input parameters of the BP neural network model.The optimization results show that BPNN-GA optimization method can significantly reduce the standard deviation of pantograph catenary contact force and improve the current collection quality of pantograph-catenary.Finally,by comparing the standard deviation of contact force between the optimized catenary and the original catenary at different speeds,the improvement effect of pantograph catenary current collection of the optimized catenary is verified.The optimized catenary can provide guidance for the design,construction and maintenance of the actual catenary.