Research On Control Strategy Of Electric Drive System For Hybrid Electric Off-highway Mining Dump Truck

Recently,with the increasing exploitation of mineral resources,the widely used conventional off-highway mining dump trucks in small and medium-sized mining enterprises are not enough to meet the expanding production and transportation demand due to its limited dynamic performance and low transport efficiency.Therefore,based on the cooperation project “Hybrid Electric Drive System Design for Off-highway Dump Truck”,a hybrid electric truck is developed by taking a conventional model as the prototype,through vehicle control strategy to coordinate the work of multi power sources,in order to effectively improve the truck's dynamic performance,transport efficiency,and ensure the fuel economy at the same time,which are significant in improving the core competitiveness of mine truck products.According to the operating characteristics and actual needs of the prototype vehicle,the design targets of the hybrid truck are clearly defined.Through comparative analysis of various structural types of hybrid powertrain systems,and considering the factors of development cycle,cost and difficulty of implementation,it's determined that maintain the basic structure of the prototype vehicle,added an electric drive system into the front axle as the auxiliary power source.Taking the dynamic performance of the truck as the goal,the key components of the electric drive system are selected and parameterized,which laid a foundation for the establishment of the performance simulation model and the control strategy of the hybrid truck.By vehicle performance analysis software,the simulation model of the prototype vehicle is established,and the driving cycle of the truck is designed based on actual operation characteristics.On this foundation,the prototype vehicle's performance is simulated and analyzed,and the accuracy of the simulation model is verified by the comparison of simulation results and the actual vehicle data.Then,the vehicle control strategy is formulated by using logic threshold value-based control method,and the design of the work modes and torque distribution of the power sources are completed.Accordingly,the control strategy model is built,and combined with the vehicle simulation model,a co-simulation is carried out,the results show that the hybrid truck meets the expected requirements and its performance is improved compare with the prototype vehicle,which proved the parameters design of the electric drive system are reasonable and the control strategy is feasible and effective,and providing reliable support for the application of the real vehicle from theoretical perspective.Based on the simulation verification of the control strategy,the control system of the hybrid truck is designed,which includes the communication network design and protocol formulation,the hardware selection of the vehicle control unit and the software implementation of the control strategy.After the completion of the loading of the electric drive system,the vehicle control system is ensured to work normally and reliably through commissioning,and then the real vehicle tests are implemented focus on the realization of control functions,the test results indicated the practicality and effectiveness of the control strategy.In this thesis,the theoretical analysis,computer simulation and real vehicle validation methods are comprehensively used in the development of the hybrid truck and conducts scientific research on the parameter matching of the drive system and the design and implementation of control strategy.The research has good practical value and provides a reference for the practical application of hybrid technology.