| In recent years,the global energy crisis and environmental pollution problems have become increasingly prominent,and the development of new energy vehicles has been highly valued by the state.The government has introduced relevant subsidy policies for the new energy sector,which has led to an explosive growth in the production and sales of new energy vehicles.Benefiting from this,the market scale of power batteries is also expanding,and the installed capacity of power batteries is constantly rising.As a core component of new energy vehicles,the production cost of power batteries accounts for 40%-60% of the cost of the vehicle,and with the retreat of new energy subsidies in the past two years,the price of upstream lithium ore and other raw materials has increased,and the profits of power battery manufacturers are constantly declining.Therefore,reducing the manufacturing cost of power batteries is one of the ways for power battery manufacturers to increase their profit margins.In this thesis,the production system of lithium-ion power batteries is selected as the object of study,and with the help of the graphical function of Petri Net,an optimisation scheme is proposed to improve the static and dynamic rhythms of this production system.This thesis firstly introduces the production process of the four sections of the lithium battery production system and analyses the sections that need to be optimised.The graphical function of Petri net is used to model the optimization section,and the effectiveness of Petri net model is verified through incidence matrix.Secondly,the existing problems of two optimization sections are analyzed.In response to the problem of low balance rate in the optimization section,an equipment scheduling model was constructed and an optimization plan was proposed based on the scheduling model,which improved the balance rate of the production line in the cathode and anode workshops of the section.A research plan for buffer capacity configuration is proposed to address the dynamic circle time imbalance caused by equipment failures in the module assembly section.The availability of the production line is analyzed based on the Petri Net model of a two-stage serial production line,and the capacity allocation scheme of the buffers is proposed in conjunction with the calculation of the safe volume of the buffers.The Petri Net model for configuring buffers is then simplified by introducing suppression arcs to the Petri Net model for two-stage serial production lines,which well demonstrates the intrinsic connection between process equipment,depot resources and buffers.Finally,the Petri net model was mapped to the Flexsim simulation software,and a simulation model was established and parameters were set.The running results of the simulation model demonstrated the effectiveness of the optimized model in improving production capacity and equipment utilization,verifying the effectiveness of the optimization plan.There are 44 figures,46 tables and 58 references in this thesis. |
