Research On Smooth Optimization Control Of Energy Storage Hydraulic Wind Turbine

With the rapid development of wind power technology,the proportion of wind power in the power resources increases year by year,the permeability of wind power gradually increases.Therefore,more attention should be paid to the random fluctuation characteristics of wind power and its impact on power grid.The output multiplicative nonlinearity and time-varying system parameters of the energy storage hydraulic wind turbine have adverse effects on the stable output of the optimal power tracking process,and then affect the power stability of the power grid output of the turbine.Aiming at the power output stability problem of energy storage hydraulic wind turbine,this paper studies the optimal power tracking and power steady output optimization control under variable wind speed.In this paper,the working principle of the unit is analyzed and the model is established.The state-space equation of the grid-connection process of the system is obtained,which lays the foundation for the optimal power tracking of the wind power system and the smooth power control based on the energy storage subsystem.The optimal power tracking control of energy storage hydraulic wind turbine under time-varying wind speed is studied.By analyzing the influence factors of wind energy absorption,taking the output power of the quantitative pump as the output and the swing angle voltage of the variable displacement motor as the input,the problems of multiplicative nonlinearity and time-varying parameters in the system were solved based on the combination of feedback linearization and integral compensation,and the optimal power tracking of the unit was realized.The feasibility of the proposed method was verified by simulation.Aiming at the power fluctuation caused by time-varying hydraulic parameters and optimal power tracking process,the hydraulic energy storage system was added into the hydraulic power transmission system,and the suction and discharge power state space equation of the energy storage system was established.The characteristics of the energy storage system were analyzed,with variable displacement pump/motor power as output and variable displacement pump/motor swing angle voltage as input.Based on the method of feedback linearization and integral compensation,a power smoothing controller for the energy-storing hydraulic wind turbine is established.The feasibility of the control strategy proposed in this paper is verified by simulation.Finally,a semi-physical simulation test platform for 30 k VA energy storage hydraulic wind turbine is built.Based on this platform,the control effect of the proposed control strategy is analyzed experimentally,and the effectiveness of the proposed control strategy is further verified.