Research On Power Regulation Of Adjustable-speed Pumped-storage System Based On Virtual Head Technology

With the interconnection of wind power,photovoltaic and other intermittent and stochastic renewable energy generation,the realization of power balance through the power throughput of energy storage system has become an urgent need for power grid operation,which is also an important factor for the sustainable development of powerg grid.So far,pumped storage is regarded as the only commercially valuable energy storage mode in the operation and control large power grids.Conventional variable-speed pumped storage system can adjust the speed quickly,so as to adjust the power,but there is still the problem that the head/head is not adjustable,the power regulation range is small and the efficiency is low.Therefore,a variable-speed pumped storage system based on virtual head technology is proposed to achieve dual regulation of speed and head,and the power regulation strategy of the svstem is studied.The feasibility of the control strategy is verified by simulationIn this paper,the design,key equipment and operation mode of variable-speed pumped storage system based on virtual head technology are studied,and the mechanism of variable-speed and variable-head technology is analyzed.Based on the operation characteristics of reversible pump turbine,the load optimization models of variable-speed pumped storage unit in power generation mode and electric mode are established.Based on the characteristics of the system,a power response control strategy for variable speed units is proposed,which is suitable for virtual pumped storage system,in which the rate is regulated by AC excitation.the speed or guide vane is controlled by reversible pump turbine,and the head is put into a high-pressure buffer tank.The simulation lodel of AC excitation motor is built by using M-based ficld-onented vector control method and MATLAB/SIMULINK plattorm.According to the load optimization process ot variable-speed unit and the control strategy of AC excitation motor,the power regulation control of variable-speed pumped storage systel based on virtual head technology is simulated.The simulation results verify the feasibility ot the proposed control strategy.