Research On The Influence Of Electric Railway Traction Load On The Operation Characteristics Of The Wind Farm

In recent years,with the rapid development of the electric railway,which has greatly promoted the rapid development of the national economy,and brought convenience to people's travel,but also caused some problems.Because the electric locomotive adopts the AC-DC type or AC-DC-AC transmission mode and single-phase power supply,the power supply system will inject a large number of negative sequence and harmonic components to the grid,and the impact of the negative sequence component can reach to several times compare to the steady state,and the safe and stable operation of the grid will be affected.Along with the increasing of the mileage and the radiation range of the electric railway,some railway will appear through the wind field,that is,the electric railway traction load and the wind farm maybe access to the same point.The wind farm usually located at remote areas,which construction of the power grid is weak,and the anti-interference ability is poor,but the power quality of the PCC is important to the wind farm.If the three-phase unbalance and harmonic content of the PCC is out of the normal operation of the wind standard,it will affect the operating characteristics of wind turbine.China's northern province Hebei area face the situation that the electric railway traction load and the wind farm centralized access to the same point,along with more and more electric railway traction station put into operation,Zhang-Tang railway,Zhang-hu railway,Lan-qi railway,Beijing-Zhangjiakou Railway will open to the traffic.The effect of electric railway traction load on the normal operation of wind characteristics will become increasingly serious.Therefore,considering the influence of the electric energy quality on the operation characteristics of the wind farm when they connect to the same point is the purpose of this paper.This paper first introduces the traction power supply system,and analyzes the reason of the negative sequence and harmonics,and theoretical analyzes the influence of negative sequence and harmonic wave and other power quality problems on the operation characteristics of wind farm;Secondly,through the evaluation of the power quality of typical substations in Zhangjiakou and Cheng-de area,the effect of the power quality of electric railway on the wind farm in northern Hebei area is investigated;Finally,based on the PSCAD simulation platform,the digital simulation model including electric locomotive,regional power grid and wind turbine generator is set up.Through the simulation analysis of electric locomotive in different traction conditions,the negative sequence,harmonics and other power quality problems inject to the grid,transmitted to the wind farm and network,effects on the wind turbine operation characteristics,including wind turbine output characteristics and inverter DC side voltage etc..Therefore,it is necessary to study the influence of the electric railway traction load on the operation characteristics of the wind farm,and provide reasonable suggestions for the planning and construction of the regional power grid and the production operation.