基于智能过程总线技术的继电保护系统可靠性研究

发布时间：2018-07-01 17:35

本文选题：变电站 + IEC61850　；参考：《广西大学》2014年博士论文

【摘要】：变电站是智能电网的关键节点,承担了电力系统电能传输和转换任务。继电保护是变电站最为重要的功能之一,是电力系统安全稳定运行的重要保障。我国第一代智能变电站通信网络构建以IEC61850标准为基础,采用过程总线通信,引入网络交换机,用简单的过程总线光纤网络取代传统变电站一、二次设备间繁多的电缆联接,并追加合并单元及智能终端对一次设备进行智能化处理,使得数字化保护在物理结构及功能运行方面与传统的继电保护存在一定区别,其可靠性有待进一步研究。另外,过程总线通信网络所固有的缺陷可能会对继电保护可靠性产生一定影响。准确评估过程总线网络性能,对保护系统可靠性分析及其网络方案优化设计具有十分重要意义。为了维持保护系统可靠性,需要对保护系统进行预防性检修。如何利用有限的维修资源使保护系统运行在最佳状态是一个值得研究的课题。本文对上述问题进行了深入研究,主要研究内容及创新成果如下： 1)据交换式以太网的工作原理以及IEC61850定义的过程总线发布／订阅机制,提出了通信网络的最小空间模型。利用最小空间模型构建过程总线通信网络的最优交换空间模型。给出了交换空间模型的多播组划分方法,为过程总线网络的优化设计提供了理论依据。 2)深入研究了过程总线的两种典型的数据阻塞模型(即,同步信号阻塞和非同步信号阻塞),针对QoS服务特性,推导以优先级为目标的数据传输延时计算公式。根据以太网的固有阻塞特性,提出了一种通过比较订阅端数据到达时间的过程总线网络时延评估算法。其特点是不需要同步时钟源,测量精度高,可作为过程总线网络性能的在线诊断工具。 3)开发了过程总线数据流量生成器和接收器,搭建了继电保护数字化仿真平台,实验测试了某一典型变电站的2种过程总线方案的网络性能,验证了所提模型和方法的正确性。 4)提出了过程总线通信故障模型,从安全性和信赖性两个方面,分析了通信故障对保护功能的影响。为了评估供电系统可靠性,建立了由通信故障引起的继电保护拒动模型。根据采样值传输特性,提出了过程总线通信故障的检测方法。 5)根据国内继电保护设计准则和IEC61850-90-4组网工程设计导则,提出了几种典型过程总线组网方案。针对复杂系统可靠性分析,引入了改进简化割集算法,并对各种过程总线方案进行了可靠性分析。 6)提出了分布式保护系统元件可靠性指标分配方法,建立了以系统可靠性和设计费用为目标的最优化分配模型,并采用评价函数法将多目标问题转化为单目标问题求解出系统的Pareto最优解。 7)采用状态空间法建立了保护系统的维修模型,提出了保护系统的可维修性指标分配方法。该项研究对数字化保护系统的运行、检修、维护等工作的合理安排具有十分重要的指导意义。
[Abstract]:Substation is the key node of smart grid, which undertakes the task of power transmission and conversion. Relay protection is one of the most important functions of substation and an important guarantee for the safe and stable operation of power system. The first generation intelligent substation communication network in our country is based on IEC61850 standard. It adopts process bus communication, introduces network switch, and replaces the cable connection between primary and secondary equipments of traditional substation with simple process bus fiber optic network. And the combination unit and intelligent terminal are added to process the primary equipment intelligently, which makes the digital protection different from the traditional relay protection in physical structure and function operation, and its reliability needs further study. In addition, the inherent defects of process bus communication network may affect the reliability of relay protection. Accurate evaluation of process bus network performance is of great significance to the reliability analysis of the protection system and the optimization design of the network scheme. In order to maintain the reliability of the protection system, preventive maintenance of the protection system is needed. How to make use of the limited maintenance resources to make the protection system run in the best condition is a subject worth studying. The main research contents and innovations are as follows: 1) according to the principle of switched Ethernet and the mechanism of process bus publish / subscribe defined by IEC 61850, The minimum space model of communication network is proposed. The optimal switching space model of process bus communication network is constructed by using minimum space model. In this paper, a method of multicast group partitioning for switched space model is presented, which provides a theoretical basis for the optimization design of process bus network. 2) two typical data blocking models of process bus are studied in detail. Synchronous signal blocking and asynchronous signal blocking), according to QoS service characteristics, the calculation formula of data transmission delay aiming at priority is derived. According to the inherent blocking characteristics of Ethernet, a process bus network delay evaluation algorithm is proposed by comparing the time of arrival of subscriber data. It is characterized by no need of synchronous clock source, high measurement accuracy, and can be used as an on-line diagnostic tool for process bus network performance. 3) A process bus data flow generator and receiver are developed, and a digital simulation platform for relay protection is built. The network performance of two process bus schemes in a typical substation is tested experimentally, and the correctness of the proposed model and method is verified. 4) A fault model of process bus communication is proposed, which is based on security and reliability. The influence of communication fault on protection function is analyzed. In order to evaluate the reliability of power supply system, a relay protection failure model caused by communication fault is established. According to the characteristics of sampling value transmission, the detection method of process bus communication fault is put forward. 5) according to the domestic relay protection design criteria and IEC 61850-90-4 network engineering design guidelines, several typical process bus networking schemes are proposed. For the reliability analysis of complex systems, an improved simplified cut set algorithm is introduced, and various process bus schemes are analyzed. 6) the reliability index allocation method of distributed protection system components is proposed. An optimal allocation model with the goal of system reliability and design cost is established. The multi-objective problem is transformed into a single objective problem to solve the Pareto optimal solution of the system. 7) the maintenance model of the protection system is established by using the state space method, and the maintainability index allocation method of the protection system is proposed. The research is of great significance to the operation, maintenance and maintenance of digital protection system.
【学位授予单位】：广西大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM77

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