Research On Modeling Of Doubly-fed Wind Turbine Plant Based On Test Data Identification

With the increasing share of the wind power in the power system, the impact of its integration is becoming widespread. To insure the stability of grids, our countries have established technical rules for connecting wind farm to power system, and apply the low voltage ride-through (LVRT) rules to every wind farm. Under the nationwide process of wind turbine low voltage ride-through ability test, how to utilize the test data to improve the LVRT ability of wind turbines has important theoretical and practical meanings.This paper firstly mentioned the technical rules at our countries and abroad, and summarized the mainstream control strategies of LVRT for DFIG-based plant, confirmed the practical strategy though comparison. Then this paper researched on the test data of DFIG wind turbine LVRT, classified and analyzed the data according to critical characteristics.By strictly theoretical analysis on the transient characteristic of DFIG when voltage dips, the computing value of the stator’s flux linkage, rotor voltage and DC line voltage were deduced, which offered theoretical base for researching on protection control strategy. In addition, taking the influence of Crowbar into consideration, a practical transient current analysis method of DFIG when voltage dips was raised.Established an integrated DFIG wind turbine model in DIgSILENT/Power-Factory, and realized the design of LVRT test equipment and LVRT protect circuit, then took sensitivity analysis for the parameters in the model, in order to determine the critical parameters which influence the characteristic of LVRT.In this paper, Fuzzy Logic was used to analyze the critical characteristics of LVRT test data to optimize the range of identification parameters; Then Genetic Algorithm was used to identify the model parameters, which realized the matching of multiple LVRT test data.