【作者】 杨凡；

【导师】 尹项根；

【作者基本信息】 华中科技大学 ， 电力系统及其自动化， 2017， 硕士

【摘要】 随着电力系统的快速发展,我国正处于区域电网互联并且正逐步形成全国电网互联的大格局,同时我国各地区能源分布与电力系统负荷分布的不均衡决定了西电东送工程的必要性,西电东送可以有效地实现全国电力资源的优化配置。而超高压直流输电技术具有输送容量大、距离远、故障隔离能力强等特点,故现阶段交直流混联技术在区域电网互联以及西电东送工程中已大规模应用,交直流混联电网的安全稳定运行直接关系到整个电力系统,乃至整个社会的安全稳定。但随着交直流混联电网的大量接入,交流电网发生的短路故障等扰动若不能及时阻断,将在直流系统中产生换相失败等后果,甚至造成直流系统紧急停运,严重威胁超高压电网的安全稳定运行,作为电力系统的重要组成部分,超高压电网的安全稳定运行水平关系着整个电力系统的安全,这就对交流系统快速主保护以及后备保护的速动性和选择性提出了更高的要求。而传统的继电保护仅利用被保护设备的信息来判别切除故障,保护动作的速度已不能满足目前电网发展的需求,同时断路器保护从保护功能角度主要实现失灵保护,其作为超高压电网重要的近后备保护,其速动性和选择性也面临着更高的要求。随着智能变电站及层次化保护技术的发展,站域保护的全站信息共享的技术优势为提高超高压电网安全稳定运行水平提供了一种新的思路,但目前站域保护正处于发展阶段,其构建模式、组网方案以及站域断路器保护等方面研究尚未成熟,故迫切需要开展超高压电网站域保护的研究。针对目前电力系统继电保护信息量不足,但站域保护构建模式复杂多样,尚未形成统一的认识,不能很好的发挥站域保护全站信息共享优势等问题,本文给出了站域保护的基本定义和作用;提出了站域保护的设计目标和原则,可为站域保护的规范设计提供指导;分析研究传统的继电保护系统在220kV及以上超高压等级面临的问题以及利用站域信息对其进行改进的基本途径,最后提出了基于SV网和GOOSE网的超高压电网站域保护构建方案,该方案较好的统一了超高压电网站域保护构建模式的形式,可以最大程度发挥站域保护的技术优势,为工程应用提供参考。针对目前站域保护采用何种组网方式尚处于探讨阶段以及站域保护与控制系统通信网络适用性有待分析验证等问题,本文结合超高压站域保护构建模式,针对性地提出了基于网采网跳模式的超高压电压等级站域保护通信组网方案,该方案能够最大程度发挥上文提出的构建模式的优势;结合实际工程应用,利用OPNET仿真软件对提出的组网方案进行了网络延时性能分析,延时满足过程层通信网络延时要求。针对目前交直流混联电网的大规模接入对断路器保护等主后备保护的选择性和速动性提出了更高的要求,以及现有断路器保护存在二次接线复杂、自适应差、死区故障无法有效解决等问题,本文提出了一种按串配置的站域断路器保护构建模式和设计方案,并提出了站域断路器保护的原理改进方案,可以优化死区故障带来的扩大停电范围的影响,有效提高保护性能;同时开发了站域断路器保护软件模块,并进行仿真验证,验证了该方案的正确性,为工程应用奠定基础。更多还原

【Abstract】 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.更多还原