Research On Optimal Scheduling Approach Of Integrated Energy System With Energy Storage

With the gradual depletion of fossil energy and the vigorous de velopment of renewable energy,how to break the existing mode of independent planning and operation of traditional energy,and realize the unified planning and coordinated operation of different energy systems is one of the keys to achieve cost reduction,efficiency increase and complementary advantages of each energy system.With the deep integration of different tastes of energy flow in the multiple energy carriers system,energy storage devices and energy conversion devices are coupled with each other in time and space.That how to evaluate the quality of various energy flows to build a reasonable energy-saving index and at the same time,study the multi period coordinated scheduling operation approach for the system,is very important to give full play to the "multi energy complementarity and cascade utilization" of the multiple energy carriers system," and to realize the economic-efficient operation of the system.Therefore,this paper firstly develops a multi-objective economic-energy saving scheduling optimization model of a multiple energy system with energy storage devices.In view of the different quality of various energy flows in the system,the traditional energy efficiency analysis approach is difficult to account for the taste distinction of different energy flows.Therefore,based on the thermodynamic exergy analysis method,the quality evaluation of various energy flows is carried out,an d then the energy-saving index for the system scheduling model is constructed.In addition,considering that the time-varying load makes it difficult for all kinds of equipment in the system to work in the rated condition for a long time,a system scheduling model considering the non-linear variable condition characteristics of the equipment is established.Secondly,we investigate the solving approach for the difficulties of multi-objective,mixed integer nonlinearity and high-dimensional variables in the scheduling model,The ε-constraint method is used to transform the multi-objective optimization into a single objective optimization,and the corresponding Pareto frontier is obtained,and then LINMAP(linear programming technology for multi-dimensional analysis of preference)approach is applied to the decision-making;for the non-linear items in the operation model,linear processing is carried out;for the difficulty of high-dimensional decision variable which are caused by multi-time periods,commercial solver of CPLEX is used to efficiently address the mixed integer linear programming model after linearization process.Finally,the scheduling model accuracy of the system,the combination choices of energy storage equipment and the implementation of demand side response mechanism based on real-time electricity price are simulated in different scenarios of summer,transition season and winter.The results show that: the operation model with the nonlinear off design characteristics of the equipment is more accurate;the combined use of cooling and thermal energy storage device is more economical and energy-saving;and the implementation of demand side response mechanism can not only reduce the operation cost but also decrease the exergy input to the system.