Research On Multi-object Capacity And Combination Optimization Of Hybrid Energy Storage System

With the renewable energy resources widely plugged in power grid,the fluctuation brought by wind power and solar energy requires energy storage systems(ESS)with high energy density,high power density quick response and long lifespan.Currently,No energy systems can solely satisfy all the demands.No energy systems can solely satisfy all the demands.The hybrid energy storage systems(HESS)have been studied and applied in multiple power applications.Currently,in the view of application,ESS could be divided into 2 categories,which are high energy density ESS and high power density ESS.The energy ESS is used for large volume energy storage in a long term.The power ESS is used during the peak power period and is normally for short-term use.The main idea of HESS is to exploit the compensation between 2 ESS types.HESS ensures that the energy ESS serves as the basic energy storage,which uses minimal charge and discharge operations to extend lifetime,whereas the power ESS works mainly in peak power period and without large amount of energy storage.With a proper characteristic compensation,the system performance and cost can be optimized.So in this dissertation,the method to build optimization model for HESS in power system is studied and the the main work finished is as follows.Firstly,the current status of research on ESS and the operating requirement of transmission sysyem,distribution system and the micro-grid with renewable energy plugged in are detailed in this dissertation.Moreover,the characteristics and data of the ESS are collected.Secondly,based on the characteristics of ESS,the operating model,annual cost and the life time model of ESS are built.And the operating optimization function and constraints in transmission system and distribution system are determined,also,the power exchange method and the reliability indicators in micro-grid are built.Moreover,the classification of ESS are determined based on the characteristics of ESS.Thirdly,the annual cost and operating optimization are combined as the multi-object capcacity optimcal allcocation,and the partial swarm optimization algorithm is applied to get the optimization capacity of HESS.Based on the result,the indication system of the comprehensive decision making in combination optimization of HESS are built,and the HESS combination is chosen based on the multi-dimensional utility mergence method.Finally,based on the application in transmission system,distribution system and the micro-grid,the models and optimization algorithms above are verified and tested to prove the correctness and effectiveness.