Research On Energy Management Strategy Of Composite Energy Storage System Including Compressed Air Energy Storage

The development of CCHP(Combined Cooling Heating and Power)microgrid is the inevitable requirement of distributed new energy power generation.It provided a solution for the efficient use of distributed power and large-scale access to the grid and improving the power quality of the grid and meet the needs of users with a variety of energy.This paper builds a composite energy storage system based on compressed air energy storage with it's unique characteristics of the cold and heat,and provides a excellent energy storage for the CCHP microgrid which co-ordinated energy storage capacity and energy storage density,environment-friendly and energy cascade to achieve the use of energy.The storage characteristics of the battery and the super capacitor are briefly analyzed in the second chapter of the paper.The heat transfer module to achieve multi-stage heat recovery has been included in the structural design of compressed air energy storage modules which is not only avoids the dependence of the energy storage system on fossil fuels,but also improves the energy efficiency of the system.And then,the composite energy storage system has been designed which combined with the three energy storage system based on overall structure.The construction of the composite energy storage system provides a effective way that take into account all aspects including high capacity,fast response,long life,high reliability and energy storage for CCHP microgrid.The compressed air energy storage system is a complex system itself which involving multiple energy forms of mutual transformation and complex structure.The thermodynamic analysis of compressed air storage system divided the system into three major aspects including compression,heat transfer and expansion.And then discusses the conversion of various energy forms on the system and the energy efficiency of every link.The three forms of energy in the system of cold,heat and electricity was independent of each other and affected each other.The distribution of energy will directly affect the overall efficiency of the system.So for different conditions we should manage the system energy effectively according to the different needs of users of hot and cold power.The focus of the composite energy storage system is the energy management and control strategy of the composite energy storage system.This paper takes full account of the utilization of hot and cold elevator level and the comprehensive efficiency of the system.On the control strategy,this paper adopts a active form of energy storage.First,Optimally Pruned Extreme Learning Machine(OP-ELM)is used to predict the distributed energy generation power by multi-time scale,and then,according to the micro-network scheduling power to determine the energy storage target power.Second,Through the method of Empirical Mode Decomposition(EMD)combined with the restrictions such as the power of wind,the load of cold and heat,the energy efficiency of the energy storage unit and capacity configuration costs,SOC and so on to manage the target power of the three energy storage.Finally,achieved a effective energy management on the system according to the micro-network on the hot and cold electric load situation,thus enhancing the overall efficiency of composite energy storage system and meet the needs of users in different forms of energy.The final of the paper,the upper monitoring system based on LabVIEW and MATLAB is designed.It realized a real-time monitoring of the system.At the same time,the control strategy is converted to real-time control signal to manage the experimental platform of composite energy storage effectively.