Research On The Assessment And Suppression Of Grid Wind Farm Caused Voltage Fluctuation And Flicker

Wind power generation transforms wind power into electrical power with no primary energy loss. This sort of power generation method is widely applied in regions with huge wind power due to its environmental benefits and high efficiency, which has contributed tremendously to energy production and reducing emissions in remote regions. The non-cyclical fluctuation of wind power leads to output power of wind turbines, which decided by wind power caught by wind turbines, also fluctuates non-cyclically. This unstable power is considered as problematic to power system operation since it would cause voltage fluctuation and flicker. This paper builds mathematical model on voltage fluctuation and flicker caused by wind power cut-in and applies study on this issue. An optimized estimation method was put forward; finally this paper proposes methods to suppress voltage fluctuation and flicker caused by wind power integration.Content of paper includes:(1) Modeling of the integration of wind power system in PSCAD/EMTDC, including:wind power generator module, step-up transformer, transmission line, step-down transformer, load, etc; And simulate the model of IEC flicker meter in chapter3part3. Inorder to simplify the IEC flicker meter propose a FFT algorithm in part4to take place of filtering sections finally verify its curacy with IEC unit flicker curve.(2) Chapter3part5studied the indicators needed to measure severity of voltage fluctuation and voltage flicker. By comparing actual measured flicker values caused by different voltage signal in two kinds of evaluation indicators Pst and ΔV10, determine the unified conversion parameter between the two indicators. The final result shows this parameter would change when the voltage signal changes.(3) Chapter4studied the engineering calculation method introduced by IEC61400-21and an optimized algorithm based on it. Wind shear and tower shadow effect is considered in the algorithm, which leads to a computing result closer to measurements.(4) Chapter5proposed a STATCOM with battery energy storage control strategy based on FBD current detection method for suppress voltage flicker problems caused by wind farm periling to the grid and achieved comprehensive inhibition of voltage flicker and harmonics. And verified its effectiveness by PSCAD/EMTDC simulation.