Research On Security Region For Regional Integrated Energy System

With the extensive promotion of the concepts of integrated energy system and energy internet,interdisciplinary integration of multiple energy and diversified development of energy fields have become important development trends of energy innovation.In this case,regional integrated energy system(RIES)is shown up as the times require,whose typical characteristics are tight multi-energy coupling and interactions between different energy systems.On the one hand,these characteristics bring many advantages such as multi-energy complementation and energy cascade utilization,while on the other hand,they also bring new challenges to the security operation of RIES.How to scientifically evaluate the RIES security has become an important issue to be solved in the development and promotion of RIES.The multi-source combined energy supply structure brings new security boundary conditions for RIES,where load can be supplied by different equipment through switch operation and valve operation.At the same time,the increasing automation level makes the output load of key equipment observable and controllable.These provide the basis for the establishment of the regional integrated energy system security region(RIESSR)theory.This paper summarizes the research status of RIESSR,establishes the RIESSR model,and gives the N-1 security verification method and security boundary solving method.On these foundations,the preventive control strategy and the optimal control strategy are provided.The validity of the RIESSR model and method are verified by a test case.(1)Combined with the predicted contingency set of RIES,based on the energy hub(EH)output pipeline segment load,the definition and model of RIESSR are proposed,and then considering engineering practice puts forward the practical security region,whose accuracy is verified through simulations.(2)The N-1 security verification method of RIES is introduced,where the N-1security verifications of the EH key equipment and key pipeline output are illustrated.Then based on the operating point at total supply capability(TSC),this paper proposes a security boundary simulation fitting solution method to visualize the RIESSR.(3)A RIES security analysis framework based on the RIESSR concept is proposed.A preventive control model is established for the insecure operating point.An optimizing control model is established for the secure operating point,and the distribution characteristics of the security degree function and efficiency degree function within the RIESSR are discussed.(4)Combined with the simulation case,the security boundary,security region model and security control strategy of RIES are proposed and analyzed.The energy supply capability,security state,security degree and efficiency degree of the RIES are discussed.Finally,the validity and accuracy of the RIESSR model and method proposed in this paper are proved.