Study On Energy Management For Multi-energy Hybrid Tramway

With the rapid development of society and economy,and the progress of urbanization,the urban problems caused by energy crisis,environmental pollution and traffic congestion are becoming more and more serious.Currently,the modern tramway with new technology has become an important public transportation to solve the urban traffic problems and reduce emission.Among them,the hybrid modern tramway based on onboard multi-energy resource has become the research focus of tramway technology at domestic and abroad due to its characteristics of energy saving,environmental protection and improving urban beauty.The dissertation aims at the research of the tramway with the catenary and an energy storage system combining battery and ultracapacitor,and the other tramway with proton exchange membrane fuel cell(PEMFC),battery and ultracapacitor as the power sources.The catenary-battery-ultracapacitor-based tramway is powered by an overhead catenary line in catenary zones,and the energy storage system in catenary-less zones.However,the fuel cell-battery-ultracapacitor-based tramway works in an autonomous way,without the connection with overhead catenary line.This dissertation mainly focuses on the research of the modeling,sizing and energy management of the two types of the tramway,the main contributions obtained in this dissertation are as follows.(1)The system model of hybrid tramway is built.Firstly,the modeling approaches applied to the hybrid powertrain are introduced,the operation characteristics of tramway and the method of train traction calculation in rail transit are analyzed.Then the hybrid tramway system model based on hybrid backward/forward approach and forward-facing approach are presented respectively.The main models of the hybrid tramway system include the multi-particle tramway longitudinal dynamics model,the driving cycle model based on distance-speed,the train transmission system model and the tramway operation control model.Finally,compared with the experimental results of a real tramway,the simulation results for a system model of tramway show that when the parameters and control strategies of the simulation system are similar to those of the real tramway test conditions in the straight railway line within 1km,the error of the average energy consumption(kWh/km)between the simulation and experiment is within 1%.(2)The energy management of the catenary-battery-ultracapacitor-based tramway is studied.First,the hybrid powertrain system structure of catenary-battery-ultracapacitor-based tramway is introduced,and the working principle is analyzed.Next,according to the analysis of the characteristics of energy storage equipment,the mathematical models of the energy storage equipment are established,and the system model of the battery-ultracapacitor-based tramway is completed.On this basis,the sizing method of energy storage equipment is proposed by taking various factors into consideration.Thereafter,the seven operation modes of hybrid system are defined,and the the balance relation of the gross power of each operation mode is analyzed,then the energy management strategy based on the system operation mode is proposed.Due to the uncertainty of the threshold design in the energy management strategy based on system operation mode,the genetic algorithm is used to optimize the control parameters in the control strategy,and the energy management strategy of the catenary-battery-ultracapacitor-based tramway based on multi-objective optimization is proposed.Finally,the energy management strategy of the battery-ultracapacitor-based tramway based on double fuzzy logic control and wavelet transform is proposed to improve the enengy management strategy.(3)The energy management of fuel cell-battery-ultracapacitor-based tramway is studied.Firstly,the hybrid powertrain system structure of fuel cell-battery –ultracapacitor-based tramway is introduced,and the operating principle is analyzed.Then the working principle of PEMFC system is introduced,and PEMFC mathematical model is established,the system model the fuel cell-battery-ultracapacitor-based tramway is completed accordingly.On this basis,the sizing method of hybrid power source is proposed by taking various factors into consideration.In addition,taking different fuel cell configuration and different energy storage equipment configuration of the fuel cell-battery-ultracapacitor-based tramway as an example,the dynamic performance of tramway is analyzed by a static calculation method.Finally,the ten operation modes of hybrid system are defined,and the the balance relation of the gross power of each operation mode is analyzed,then the energy management strategy of fuel cell-battery-ultracapacitor-based tramway based on the system operation mode is proposed.Due to the uncertainty of the threshold design in the energy management strategy based on system operation mode,the energy management strategy of the fuel cell-battery-ultracapacitor-based tramway based on multi-objective optimization is proposed to optimize the control parameters.(4)The test platform of hybrid powertrain is developed.Firtly,according to the the functional requirements of the hybrid powertrain test platform based on the hardware-in-the-loop(HIL),the hierarchical design of the hybrid test platform is established,and the equipment composition and working principle of each layer are stated.Secondly,the test platform is developed using model-based design(MBD),which can be used for the functional test of some components,development of control strategy,operation simulation of tramway,etc.Finally,the function of the platform is test by taking the operation simulation of the catenary-battery-ultracapacitor-based tramway in a line as an example.