Research On Grounding Design And EMC Key Technology Of Trolley Bus

Urban public transportation,as one of the main modes of transportation in today’s city,greatly facilitates people’s life and travel.In recent years,driven by the development direction of resource saving and green environmental protection,the new trolley bus has developed rapidly.With the development of vehicle performance and technology innovation,the integration of on-board electrical equipment and various cables makes the electromagnetic environment of the vehicle more complex.The EMC problem will not only threaten the safety and stability of trolleybus operation,but also cause electromagnetic pollution to the urban environment.Therefore,it is necessary to study the EMC performance of trolleybus.Taking trolley bus as the research object,this paper systematically studies the EMC limit,EMC key technology and grounding design of trolley bus.Firstly,this paper introduces the principle of electromagnetic radiation of trolleybus and the electromagnetic shielding principle of the box.The coupling mechanism of electromagnetic interference is calculated and analyzed by means of coupling model and equivalent circuit.The electromagnetic shielding principle of cable on trolleybus is analyzed through formula derivation.The analysis and research of EMC mechanism is the theoretical support for the subsequent simulation and the vehicle grounding design.Secondly,in this paper,the trolleybus EMC limit and test method for analysis and research,analysis of the trolley car main interference sources,based on the different criteria of electromagnetic compatibility EMC limit and contrastive analysis of the key parameters,in combination with the practical situation of trolley buses,determine the trolleybus EMC limits and put forward suitable for trolleybus test method,It includes the test purpose,test equipment,test layout,test method and other key contents,which can be used to guide the EMC test of trolleybus.Then,according to the EMC mechanism and combined with the EMC limits and key parameters of on-board equipment,this paper uses CST electromagnetic simulation software to conduct EMC simulation research on on-board electric equipment and cables of trolleybus.Simulation including on-board network control equipment VCU radiation emission and vehicle CAN communication cables between the immunity simulation,the simulation results for trolleybus equipment EMC standard advice,selected by changing the equipment enclosure shielding materials were put forward to improve the electromagnetic compatibility of automotive equipment,through additional shielding enhance the anti-interference ability of the vehicle CAN communication cable,It has guiding significance and reference value to solve the EMC problem of trolleybus.Finally,this paper analyzes the grounding design principle of trolleybus from multiple aspects,including the grounding principle of on-board equipment,the calculation and analysis of the cross-sectional area of the grounding conductor and the selection of the grounding mode of the cable shielding layer.From the practical engineering application and ensure the trolleybus the perspective of electromagnetic compatibility,grounding design principle of the trolleybus grounding design,concrete including on-board electrical equipment grounding design and shielded cable shielding layer design,from the perspective of engineering ascend trolleybus on-board equipment and cable the rationality of the design of electromagnetic compatibility and reliability.