The Research On Inductive Filtering And Its Application In Access Systems Of Wind Farm

"Clean energy garbage power" is the reality characteristic of wind power,in which the harmonic is the main factor.This paper aims to apply inductive filtering technology to wind power access system,to eliminate the effects of harmonic on the wind power access system.Firstly,we had a brief introduction about the structure of wind farms,and further analyzed the sources of wind farm harmonics.We analyzed the characteristic of the harmonic which generated by the PWM-controlled voltage source converter.At the same time,we studied the harmonics data of a wind farm which used PWM-controlled voltage source converter.Then we compared the traditional harmonic suppression methods and inductive filtering technology,and the latter is better.After determining the use of inductive filtering technology to suppress harmonics of the wind farm,we carefully analyzed the principle of transformer inductive filtering technology from the perspective of the circuit and harmonic magnetic flux suppressing of transformer respectively.Simultaneously,we proposed three conditions to achieve transformer inductive filtering technology.After that,we introduced the basic topology structure of harmonic shielding transformer,and analyzed the principle and winding arrangement of inductive harmonic shielding transformer and the feature of the transformer.On this basis,as an opportunity of designing inductive filter for the wind farm mentioned before according to the harmonic characteristic of the wind farm,we elaborately described the entire designing process and presented the parameters of each components of the inductive filter.Finally,we presented and analyzed the harmonic treatment effects of no filters used,traditional filters used and inductive filters used.The results suggested that using inductive filtering technology could enable the power quality of the wind farm exceeding national standards.The study not only broadened the application of inductive filtering technology,but also solved the power quality problem of the wind farm,which have important practical engineering significance for promoting the developing of the wind farm.