Research On Automatic Generation Control Of Wind Turbines And Energy Storage System In A Wind Farm Based On Wind Power Output Capability Assessment

The development of social economy has accelerated the consumption of energy resources.As one of the most effective ways to use new energy,wind power has higher and higher penetration rate in the power grid.The power grid has a higher demand for smooth and controllable wind power,which means the needs of a certain automatic generation control(AGC)capability of wind power,enabling wind farms to respond to active power dispatching commands from the grid like conventional power plants.In this dissertation,related research on the evaluation of the power output capacity of wind farms in AGC and the active control strategy of wind farms with energy storage system has been carried out.The specific work is as follows:First,models of variable-speed variable-pitch wind turbine generator(VSVP WTG)and wind farm active control system are established.Through the analysis of the simulation results,the importance of the power reference in the AGC control for the wind power output tracking scheduling plan stably and accurately is strengthened.Then,based on the energy conversion status of WTG,the available wind power(AWP)of VSVP WTG in AGC control is estimated with the help of classification regression tree.What's more,the AWP of the whole wind farm has been assessed on the base of wind farm speed model,which takes the wake effect into account.The validity of the AWP estimation results was verified through simulation.Finally,the AWP estimation result is applied to the AGC control strategy of wind farm with energy storage system,used as the reference for the maximum wind power output capacity.With the goal of minimum deviation of overall output,the start/stop cost of WTGs and the operation cost of energy storage system,an active dispatching strategy is established to optimize the active power command of WTGs and energy storage system in the wind farm.Also,the influence of AWP estimation error on wind power output is analyzed,and the real-time modification strategy of active power command is proposed to reduce the possibility of output drop caused by AWP estimation error.The effectiveness of the proposed dispatching strategy and the modification strategy is verified through the simulation.The improved strategy strengthen the active power control ability of the wind farm in AGC.