Design Of DC System In Substation And Its Fault Research

As the working power of protection,monitoring,control,automatic devices,DC system is the infrastructure of the control and protection for power system in transformer substation.In the case of AC system used for substation disappeared,the DC system must ensure continuous supply of power.It can be said the reliable operation of the DC system is the key to ensure the safe operation of the power system,so,more and more people pay attention on the research on the DC system in recent years.With the development of modern science and technology,especially computer and communication technology,power s ystems developed toward the direction of integrated automation,centralized network.It requires more stability and reliability of DC system used for substation.Therefore,it is of great importance to research the design of DC system,analyze the abnormal problems that may be encountered in the DC system and propose solutions to the different types of DC system anomaly.This paper described the structure of the DC system,analyzed the function and the principles of the various components of DC system,analyzed the design principles and the issues that need attention of the battery,charging device,the voltage of the DC bus,the wiring of DC system and the feed network of DC system.Then this paper analyzed the DC system ground fault,discussed the treatmen t of different types of DC ground fault with cases.This paper studied the technology of isolated earth detection,analyzed the principle of the method of the balanced bridge,the AC signal injection and DC detection.At last,this paper analyzed of the advantages and disadvantages of each method,introduced the operating characteristics of the breaker in DC system.