Metro Power Supply System Relay Protection Configuration And Setting Calculation Software Design

With the continuous development and progress of the times,the influx of people to the city,making the city continues to expand.In the process of urban modernization,the subway provides an efficient solution to solve urban traffic congestion problem due to its large carrying capacity and high traffic efficiency.The safe operation of the power supply system is essential during the operation of the subway.And relay protection provides vigorous support for the safe operation of the metro power supply system.In recent years,the subway has developed more rapidly,at the same time the workload of the relevant designers has been increased.In order to improve the work efficiency of relevant staff and speed up the work schedule,it has practical significance to develop a relay protection setting calculation software for metro traction power supply system.Firstly,the structure of the subway power supply system is explained in this paper,including AC and DC power supply systems,which details describe the structure and basic working principle of the rectifier transformer and rectifier circuit in the DC traction power supply system.Secondly,types of relay protection are introduced in this paper that each power equipment should be equipped with,as well as the principles of each relay protection and the calculation method of setting are introduced.The Protected objects of AC power supply system includes transformers,busbars and medium voltage network transmission cables.The types of protection configured include quick current interruption,timed limit overcurrent protection,zero sequence protection,longitudinal differential protection and so on.In the DC power supply system,various protections are set in the DC incoming cabinet,the feeder cabinet and the negative cabinet..Protection types include high current trip protection,DDL protection,timed limit overcurrent protection,and frame leakage protection.The calculation method of the rated current of the AC transformer,the short-circuit current of the AC and DC power supply system are explained in this paper.And the process of DC short-circuit current calculation is illustrated.Then the short-circuit current calculation and relay protection setting calculation method has been explained by a case in this paper.Finally,the setting calculation software is designed and implemented,on the basis of analyzing the requirements of the relay protection setting calculation of the subway power supply system.Analysis and comparison of various software development platforms,Delphi was selected as the software development platform due to Delphi has advantages of short development time and the code is readability.After the software is done,the software function is verified by performing protection setting calculation on a subway power supply system.