Research On The Mode Of EHV Substation Area Protection Construction And Circuit Breaker Protection

With the rapid development of the power system,our country is in the pattern of regional power grid interconnection which now is gradually expanded to the whole country,while the unbalanced distribution of our country's area energy and power system load determines the necessity of West-East power transmission project.This project can optimize the effective allocation of electric power resources transmission nationally.While HVDC technology has the characteristics of large transmission capacity,long distance,fault isolation ability,AC / DC hybrid technology has been largely used in regional power grid interconnection and West-East power transmission project at this stage.The safety and stable operation of AC / DC hybrid power grid is now directly related to the power system and the whole society.If we can't block AC grid short-circuit fault disturbance timely when it happened it will have consequences of commutation failure in DC system,and even cause emergency outage of DC system which will seriously threat the safe and stable operation of EHV power grid.As an important part of power system,the level of the safe and stable operation of UHV power grid is related to the safety of the whole power system.So we have to put forward higher requirements to the rapidity and selectivity of the AC system fast main protection and backup protection.While the traditional relay protection only uses the equipment information to determine the fault,the speed of protection operation cannot meet the current needs of power grid development,at the same time from the angle of protection function the circuit breaker protection mainly realizes the failure protection,as an important backup protection of EHV system,its rapidity and selectivity are also facing higher requirements.With the development of Smart Substation and hierarchical protection technology,the advantages of the total information sharing technology of domain protection station provides a new idea to improve the level of safe and stable operation of EHV power grid,but currently the station domain protection is in the development stage,its construction model,network scheme and station domain circuit breaker protection and so on don't mature yet,so it is urgent to study the domain protection of EHV power grid station.To solve the problems like the insufficient information of power system relay protection,complicated mode of the substation area protection construction,lacking of an unified understanding,insufficient development of the advantages of domain station information sharing,this paper presents the basic definition and function of substation area protection;puts forward the design goals and principles of Substation area protection which can provide guidance for the design specification of substation area protection;analyze the problems of relay protection system of traditional EHV when faces 220 kV and above and the basic approaches to improve the station of the domain information,at last the paper proposes a protection scheme of UHV system station domain construction based on the SV network and GOOSE network.The scheme better unifies the construction mode of substation area protection of EHV system,can maximize the advantages of substation area protection,provides a reference for engineering application.At present,for issues like the substation area protection network is still in the discussion stage and the applicability of station area protection and control system of communication network needs to be analyzed this paper puts forward the protection domain communication network scheme of ultra high voltage level network mining network station based on the jump mode combining with the construction mode of EHV substation area protection.This scheme can maximize the advantage of the construction model proposed above,it also analyzed network delay performance of this networking scheme using the OPNET simulation software based on practical engineering application,it shows the delay can meet the requirement of process layer communication network.To solve the problems like the higher requirements of the selectivity and speed of main backup protection as the circuit breaker protection with the current access for large-scale AC / DC hybrid power grid,the complicated secondary connection of the circuit breaker protection,poor adaptability,dead zone fault,this paper proposes a domain circuit breaker protection construction mode and configuration scheme.The both centralized and distributed configuration scheme can better solve the problems of the existing circuit breaker protection station.We also propose a station domain circuit breaker protection principle improvement scheme which can minimize the influence of power failure range brought by dead zone fault based on the advantages of domain station information sharing and improve the protection performance.At last this paper develops a station domain circuit breaker protection software module,and the simulation results have verified the correctness of the program which fixed foundation of the engineering application.