Research On Operation Control Strategy Of Virtual Pumped Storage System Based On Linear Motor

Energy storage technology is the key technology of smart grid.It is of great significance to integrate large-scale new energy,implement the ’two alternatives’ and transform energy structure.Compressed air energy storage(CAES)technology can reach the same capacity as pumped storage power station at present,with characteristics of large system capacity,low construction and operation cost,long lifetime,unlimited energy storage period and site selection,and has wide applicability and application prospect.According to the thermodynamic principle analysis,isothermal compressed air energy storage technology has higher efficiency in theory.Therefore,a virtual pumped storage system based on isothermal compressed air energy storage principle is proposed in this paper.The system operation control strategy based on linear motor is studied,and the feasibility of the control strategy is verified by simulation.In this paper,the design,key equipment and operation characteristics of the virtual pumped storage system(VPSS)are studied.According to the different requirement of liquid in VPSS,three kinds of liquid sources are set as working medium.Based on the characteristics of VPSS,the constant power operation control strategy suitable for the steady operation of VPSS and a power adjusting operation control strategy used to adjust power to meet the power requirements of power system for energy storage station are proposed.The former is mainly researched in this paper.The basic model and the hierarchical relay model of the VPSS are constructed.The operation strategy and mathematical model of the two system models are analyzed and the control strategy of the linear motor using speed and force as control command is obtained.The simulation model of permanent magnet synchronous linear motor(PMLSM)is built with MATLAB/SIMULINK and magnetic field vector oriented control method based on SVPWM is used to control the PMLSM.According to the system operation strategy and linear motor control strategy,the basic model and hierarchical relay model of VPSS based on linear motor are simulated and the simulation results verify the feasibility of the proposed constant power operation control strategy.