The Research On The Fault Of DC Grid Connected Wind Farm

The wind power generation technology is becoming an important research field in countries around the world. The global wind power installed capacity is increasing and the number of wind farm accidents are also increasing. Therefore, how to from the fault study of wind power system to improve the safety and reliability of wind power grid connected operation is meaningful.This paper studies the direct drive permanent magnet synchronous generator for grid connected wind farm model of VSC-HVDC based on the experiment simulation of the common faults of various kinds of wind power system.Firstly, this paper introduces the situation of energy and the current global environment issues in detail, discusses the superiority of the development of wind power industry. The present condition of wind power generation at home and abroad were summarized and analyzed the global large-scale wind farm operation fault in recent years.Secondly, this paper introduces the wind induction generator, doubly fed wind power generator, direct drive permanent magnet synchronous wind generator, analysis of advantages and disadvantages of the three models and their application prospect in the field of wind power generation. Analysis of AC grid, the traditional high voltage DC grid and VSC-HVDC of three kinds of wind power generation and comparison. VSC-HVDC grid connected mode has obvious advantages. Analysis of the typical topology of grid connected wind farm AC and DC grid connected mode and put forward by DC interconnection form for the grid connected mode of the style of the electric field.Thirdly, it introduces wind farm based on VSC-HVDC system structure, analyzes principle of wind turbine, permanent magnet synchronous generator and VSC-HVDC system. At the same time, their mathematical model and operating characteristics are established. The main control mode of VSC-HVDC system including current inner loop control, power outer loop control and controller of current limiting principle. Also, indicates that the control mode of grid connected wind farm system of wind farm side converter station and grid side converter station based on VSC-HVDC.Finally, DIgSILENT/PowerFactory simulation software, simulation parameters of wind power system and the whole model structure were introduced. A detailed analysis of fault causes, basic principle, fault hazards and response about grid short-circuit fault, DC side fault, the common faults of generator, wind turbine blade angle control fault, and then simulated and analyzed various kinds of fault types.