Modeling And Control Of Power Quality Problemof Electrified Railway Traction Substaion

With the rapid development of electrified railway, power quality problems caused by that is payed more and more attention. However, because of some reason, little people do the research in this area. So, the analyzes and management of power quality for electrified railway system is studed in this paper to improve the stability and security of power system.The following five parts is included in this paper, from the aspects of analysis and managemen.The study begins with a single locomotive modeling and simulation, electrical topology is divided electric locomotives into two kinds, AC-DC-AC and AC-DC type and their electric models are constructed respectively.dynamic model of the electric locomotive, which is analysed from road conditions, working conditions and scheduling, is converted into power/current model, which is used to analyze electric locomotives harmonics and voltage fluctuations and express the final results as harmonic source model.Then, considering the influence of traction transformer, and the impact of the traction transformers for harmonic and negative sequence current is analyzed, And the conclusions in the load balancing and imbalance typical load is obtained by PSCAD simulation, from which a more general situation is educted.Thirdly, On the basis of locomotives and traction mainstream model, a dynamic model of traction station, analyzes the mechanism and pass a comprehensive energy law traction station quality issues raised starting from the perspective of the dynamic characteristics of power quality based on support vector machines the power quality classification and assessment methods, the introduction of the relaxation factor to establish the optimal classification face, choose Gaussian kernel function as the basis for decision-support vector machine is given, the establishment of a sound station electrified railway traction power quality rating methods, and the method was validated.Fourthly, Hybrid locomotive actual load for the study, the introduction of scheduling, working conditions, load and other factors that will contain multiple electrified railway locomotives comprehensive evaluation and analysis of power quality problems, based on dynamic characteristics of the double Fourier analysis of indicators and support to the classification theory methods for comprehensive power quality classification. To study the dynamics of a typical power quality compensation device, the device will be different compensation corresponding to different types of comprehensive power quality problems, to establish economic, safe and practical multi-objective optimization function, based on a comprehensive assessment of power quality classification results, configure the power quality compensation devices and optimize their capacity, proposed compensation scheme optimized to achieve intelligent electrified railway power quality flexible adjustment.At last, an assessment of the electrified railway in China is made. And the trends of power quality management are analyzed.In conclusion, the typical power quality problems of electrified railways are studied by theoretical analysis and simulation in this paper. And all the results are verified in the Houfeng railway station on Fu-Xia Line.