Study On Operation Mode And Control Method Of Virtual Pumped Storage Power Station

With a large number of random and intermittent renewable energy such as wind power and photovoltaic are connected to the power grid,it is an urgent need for the operation and control of the power grid and an important factor for the sustainable development of the power grid to use the energy storage system with flexible power throughput to achieve power system power balance.Among the existing energy storage technologies,there are mainly two kinds of technologies that can achieve large-scale energy storage:pumped storage and compressed air storage.High efficiency hydraulic equipment is used for pumped storage,but its development and utilization are limited by the harsh conditions built on the mountain.Compressed air energy storage technology has the characteristics of large system capacity,low operation cost and less limited construction site.However,the efficiency of traditional compressed air energy storage power station is not high,and there is no mature application project.In this paper,a virtual pumped storage power station based on compressed air energy storage is proposed by combining the two technologies of pumped storage and compressed air energy storage,which can get rid of the dependence of Pumped Storage Technology on special geographical conditions.At the same time,variable speed pumped storage technology and virtual water head technology can realize the dual regulation of speed and head/head.Compared with ordinary pumped storage power station,the power regulation range is larger and the efficiency is higher.In order to realize the stable and continuous regulation of power station and safe and efficient operation,it is very important to study the operation mode of virtual pumped storage power station and the joint control method of each module.This paper studies the structure,operation process,key equipment and control mode of the virtual pumped storage power station based on compressed air energy storage.According to the control relationship between the generated head of the high-pressure pool and the speed of the pump turbine,three operation modes of power plant are defined,including head speed matching mode,head priority mode and speed priority mode.Through the joint control of each module of the power station,the operation control method under each mode is put forward.Different operation modes and control methods are selected for each stage of power plant operation,and mathematical modeling and parameter calculation are carried out for power generation and electric operation conditions.Through Maltab and Mathematica simulation,the adjustment speed of the driving equipment of the hydraulic potential energy conversion module and the change of the head of the high-pressure pool of the constant head pumped storage module are simulated.The results of different strategies are compared and analyzed to verify the feasibility of various control strategies.The head change of virtual pumped storage power station in the whole process of power generation and electric operation is simulated to realize the efficient and stable operation of virtual pumped storage power station.