Research On Modeling Of Wind Farm Based On Test Data Identification

With the rising proportion of wind power in power system in recent years,the problems of wind power’s volatility,weak support and low immunity have become increasingly prominent,which brings great challenges to the safe and stable operation of power system.Establishing an accurate simulation model of wind turbine and wind farm is the basis for analyzing and calculating the power system with large-scale wind power access,and is also the premise and key to the operation mode arrangement,wind power operation characteristics analysis and power quality analysis in power system dispatching.Based on the above background,this paper mainly studies the following aspects:(1)The hardware-in-the-loop simulation low-voltage fault ride-through test system of direct-drive wind turbine based on controller is established,and the low-voltage ridethrough test method of wind turbine is introduced,and the hardware-in-the-loop test of low-voltage ride-through of wind turbine under various working conditions is carried out.The hardware-in-the-loop test results of wind turbine controller are verified by comparing the hardware-in-the-loop test results with the field low-voltage ride-through test results.(2)In this paper,the steady-state control strategy of converter on the generator-side and grid-side of direct-drive wind turbine is studied,the key parameters of steady-state control are refined,and the impedance analytical expressions of subsystems on the generator-side and grid-side are derived.The key parameters identification method of steady-state control of wind turbine based on frequency-domain impedance fitting is adopted,and the key parameters of steady-state control of generator-side and grid-side converters are identified.(3)Fault ride-through control adopts the control architecture of external characteristic fitting,and switches fault ride-through control loop and steady-state control outer loop by fault state judgment to realize low-voltage fault ride-through;The fault control strategy of wind turbine is introduced,and the key parameters of fault control are determined.The identification method of key parameters of wind turbine fault control based on genetic algorithm is proposed,and the key parameters of fault control are identified based on low penetration test data,and the accuracy of the model is verified.(4)Based on the direct-drive wind turbine model,a wind farm is built in MATLAB,and the wind farm is equivalent by single machine aggregation method based on capacity equivalence.By comparing the equivalent results with detailed modeling method,the effectiveness of the equivalent method is verified.