Research And Application Of Blockchain Technology In Electric Vehicle Charging Transaction Management

With the rapid growth of electric vehicle charging demand,the traditional centralized charging transaction management system has become a major bottleneck for the development of the current electric vehicle industry due to the drawbacks of high construction cost,low utilization rate,and maintenance difficulties.Therefore,the construction of a new charging transaction management system that uses private charging stations for commercial operation has become a powerful way to break through this bottleneck and has received extensive attention from academia and industry.In such an open and distributed network,how to manage and restrict the behavior of both sides of the transaction in the absence of a central node is the key to ensuring the normal operation of the charging transaction management system.Focusing on this issue,this thesis researches both the trust management of the charging station and the management of the EV charging transaction,and proposes a trust assessment method applicable to charging stations and charging users respectively,as well as a charging right allocation mechanism and charging transaction strategy based on trust indicators,to achieve the purpose of promoting the honest performance of transaction behaviors between charging transaction parties,thereby ensuring that charging transactions can operate reliably and orderly.On this basis,this thesis designs a blockchain-based transaction data and trust evaluation data storage system,which enables the blockchain system to accommodate double-granularity data through an improved two-layer chain structure.The main work and features in this thesis are as follows:(1)A trust evaluation method based on subjective and objective factors is proposed to evaluate the reliability of charging station nodes more comprehensively and to integrate the trust index of the charging station into the allocation of charging rights of the charging station.The experimental results show that the evaluation method can effectively distinguish the service quality of charging station nodes,and the charging right allocation mechanism can enable the power supply system to allocate charging rights for each charging station more reasonably during the peak load period.(2)A charging transaction management system based on a two-layer blockchain structure is designed,and the fine-grained trust credential data,transaction data,and coarse-grained trust evaluation data are stored in layers.While making transaction data traceable,auditable and immutable,it can also quickly respond to query requests for trust assessment data.(3)To address the shortcomings of the classical proof-of-work mechanism in terms of energy consumption and efficiency,this thesis proposes a consensus algorithm based on the "roulette" strategy,which probabilistically determines the bookkeeping nodes based on the trust evaluation index of charging stations,thus greatly reducing the arithmetic power consumption in the consensus process and significantly improving the consensus efficiency.At the same time,the algorithm can also prevent high credit nodes from monopolizing the bookkeeping rights and prevent the system from degenerating into a "centralized" model.(4)This thesis proposes a transaction method based on electricity price satisfaction.The electricity price that can reflect the real-time load situation is used as the reference electricity price,and transactions are matched based on smart contracts.At the same time,a trust evaluation mechanism for users is designed to increase the cost of users’ untrustworthy behavior,so as to achieve the purpose of restricting and regulating user behavior.The experimental results show that the method proposed in this thesis can reasonably determine the transaction price and summarize the transactions,and also can promote the balanced distribution of charging loads on the grid.(5)Based on the above work,a corresponding prototype system is designed and implemented to demonstrate the practicability and effectiveness of the above work.