Modeling And Efficiency Optimization Control Of Vanadium Redox Battery

With the continuous progress of industrialization,large-scale energy storage technology is increasingly mature.As a kind of electrochemical energy storage technology,Vanadium Redox Battery(VRB)has been widely used in large-scale energy storage field because of its safety,long life and flexible system design.However,the operation efficiency of VRB energy storage system is the key factor affecting its large-scale development,so how to establish an accurate and comprehensive VRB model and improve its system efficiency are the key problems need to be solved.Therefore,this paper is based on the structure,working principle and performance influence mechanism of VRB,a VRB multi field coupling model is constructed,and a VRB efficiency optimization control strategy is proposed.The main research contents are as follows:Firstly,the VRB mechanism of influence on the performance is established.The effects of key components,such as electrode,ion exchange membrane,bipolar plate and electrolyte,are summarized.The mechanism of VRB performance is divided into static characteristics and dynamic characteristics.The static characteristics mainly include the influence mechanism of performance parameters of battery related components,and the dynamic characteristics mainly include the influence mechanism of dynamic parameters during battery operation.Secondly,the multi field coupling model of VRB is constructed,which is based on the structure,working principle and performance influence mechanism of VRB,the VRB equivalent circuit model,hydrodynamic model,electrochemical model and temperature model are coupled.The equivalent circuit model shows the electrical relationship of VRB as a whole,and the hydrodynamic model,electrochemical model and temperature model show the momentum transfer process,mass transfer process and heat transfer process.The four models combine the three transmission and one reverse in VRB operation with the electrical relationship,and show the input and output characteristics of VRB comprehensively and accurately.The material performance parameters of VRB components,such as electrode,ion exchange membrane,bipolar plate and electrolyte,can be used as input in the model to flexibly build the specified VRB.Therefore,VRB model can be established not only according to the battery parameters such as power and capacity,but also according to the performance parameters of component materials.Finally,an optimal flow control strategy considering temperature change is proposed.In order to effectively improve the system efficiency of VRB,the influence of flow rate,temperature and other factors on VRB should be considered.Through the simulation and analysis of VRB model,the influence of flow,temperature and other parameters on the efficiency of VRB system is obtained.When the VRB working in the different state of charge and temperature,selecting the optimal flow can effectively improve the system efficiency of VRB.At the same time,the VRB hardware in the loop simulation platform is built,which verifies the effectiveness of the multi field coupling model and the optimal flow control strategy considering the temperature change.The conclusions can provide some theoretical guidance for practical engineering.