Application Of Modular Superconducting Magnetic Energy Storage System In Power System

With the development of modern society,the scale of power grids has been expanding,and intermittent energy sources such as wind power and photovoltaics have been increasing,and the power grid structure has become more and more complicated.Energy storage technology is of great significance for improving the stability of power systems,improving power quality,and assisting in the integration of new energy power generation,and has received extensive attention from countries around the world.Among many electrical energy storage technologies,Superconducting Magnetic Energy Storage(SMES)stores electrical energy in the form of magnetic field energy in superconducting magnets,which is unique in terms of response speed,dynamic power compensation,number of charge and discharge,and lifetime.The advantages have broad application prospects.Due to the self-characteristics of superconducting materials and the constraints of power conversion systems and refrigeration systems,there are still many difficulties in achieving SMES of dozens of MJs in a single machine.Therefore,this paper proposes a modular superconducting magnetic energy storage system(M-SMES: Modular SMES),which aims to realize the modular integration and distributed layout of SMES through advanced control technology,which is used to enhance the stability and improvement of the power system.The quality of power supply and the ability of the grid to accept intermittent new energy sources are of great significance for the application and promotion of SMES in power systems.This paper has carried out in-depth research of M-SMES on the topological structure and coordinated operation.The main work and achievements are as follows:(1)This paper firstly clarifies the concept of "modularization".Starting from the modeling of single SMES,it extends the two levels of magnets and power electronics,and proposes the topology structure of modular SMES and its control design method.(2)Secondly,according to the different characteristics and operating conditions of SMES magnets,the coordinated operation mode of modular SMES and the corresponding power allocation strategy are discussed from three aspects: synchronous operation,distributed operation and dispersion operation.(3)This paper establishes the technical economic evaluation model of M-SMES,and uses this model to calculate the cost of a single large-capacity SMES and M-SMES.The life cycle cost model is introduced.The total cost of the battery and its mixed energy storage with a single SMES and M-SMES is compared and analyzed,which illustrates the feasibility of M-SMES in economic application.