【作者】 杨增力；

【导师】 段献忠； 石东源；

【作者基本信息】 华中科技大学 ， 电力系统及其自动化， 2008， 博士

【摘要】 复杂的电网结构和多变的运行方式给电网继电保护整定计算及其可靠动作带来了新的挑战。研究继电保护整定计算、提高继电保护可靠性及协调动作的能力,对及时切除故障、避免恶性事故的发生具有重要的意义。本文致力于超高压线路继电保护整定计算及协调问题的研究,内容涉及整定计算原则与方法研究、整定计算软件通用性及自动化技术研究、继电保护系统脆弱性评估方法研究以及广域继电保护算法研究等方面。部分研究成果已成功应用于多家省、区域电网继电保护整定计算系统,有效提高了整定计算的效率及保护定值的准确性。为了更好的发挥继电保护装置的作用,对输电线路接地故障后备保护的功能进行了研究。指出了零序电流保护、接地距离保护和断路器失灵保护在切除接地故障时所处的地位和应起到的作用;提出了新的零序电流保护和接地距离保护整定计算原则。该研究使得接地故障各后备保护的功能更加清晰和具有层次性。提出了新的接地距离保护整定计算方法:为了充分考虑零序互感对接地距离保护性能的影响,提出了简单实用的零序电流补偿系数计算方法;针对目前接地距离保护整定计算方法的不足,提出了系统的基于感受阻抗的整定计算方法。该方法具有更普遍的适应性,基于该方法的保护定值更加精确。同时,提出了基于运行约束条件的距离保护自适应整定计算方法。在整定计算的自动化和智能性方面,提出了基于灵敏度约束条件的线路保护整定计算自动调整方法。在引入整定保护自身灵敏度约束条件、远后备保护灵敏度约束条件和远后备保护灵敏度传递约束条件等灵敏度约束条件的基础上,通过两个调整阶段实现了线路保护整定计算的自动调整。基于该方法的整定计算软件可代替工作人员实现保护定值的自动调整。同时,提出了一种实用的保护配合顺序优化方法,该方法可以提高保护定值的稳定性。对继电保护离线整定模式和在线整定模式进行了分析,并对在线整定计算系统的整体结构及若干关键技术进行了探讨。以实际电力系统为例,对离线模式和在线模式下的保护定值进行了详细的比较分析。从中可以看出,实现在线整定对提高继电保护性能具有重要的意义。继电保护整定计算具有多样性和区域性,为了减小其对继电保护整定计算软件开发和推广的影响,对整定计算软件的通用性进行了深入的分析,内容涉及运行方式组合、原理级保护整定计算、装置级定值整定计算和定值通知单等方面。提出了基于原则选择的运行方式组合通用性解决方案和基于原则自定义的原理级保护整定计算通用性解决方案,并对通用原理级保护整定计算软件的实现进行了较为详细的介绍。提出了一种评估输电线路继电保护系统脆弱性的方法。该方法结合线路继电保护系统的功能组成特点,从保护装置和保护定值两个方面分别建立了线路继电保护系统的误动概率模型,以负荷损失的形式反映继电保护误动对电力系统运行造成的影响,并据此建立了线路继电保护系统的脆弱性指标。该脆弱性指标可以很好的反映出电网继电保护的脆弱环节。为了充分利用多点故障方向信息来完成故障元件的判断,提出了一种基于方向比较原理的广域继电保护算法,并构建了基于变电站集中式结构的广域继电保护系统。该广域继电保护系统根据发电厂或变电站的主接线形式和方向元件位置,分别形成厂站内一次设备和厂站出线对应的一次设备/方向元件关联矩阵。电力系统发生故障后,广域继电保护系统根据方向元件指示的故障方向信息和一次设备/方向元件关联矩阵形成一次设备/故障方向关联矩阵,并完成故障元件的识别。更多还原

【Abstract】 Complicated power network topology and changeful operating conditions bring challenges to protective relay coordination and reliable operation. It is very significative to investigate protective relay coordination and to improve the reliability and ability of cooperative operation of protective relays for protective devices to isolate faults in time and avoid great accidents. This dissertation devotes to the study of protective relay coordination and cooperation, including the research on relay coordination principles and approaches, the research on coordination automation technology and universality of relay coordination software, the research on vulnerability evaluation of relay protection system for transmission liens, and the research on wide area relay protection algorithm. Some research productions have been applied in the relay coordination software for many provincial and regional power networks, and the software improves the efficiency of relay coordination and the veracity of relay setting.The specific functions of different backup protections for grounding fault in ultra-high-voltage transmission lines are investigated to make full use of protective devices. The specific roles and functions are presented when zero sequence overcurrent relays, ground distance relays and breaker failure relays are used to isolate grounding faults. New priciples for calculating the settings of zero sequence overcurrent relays and ground distance relays are discussed based on the new presented scheme for configuring zero sequence overcurrent relays. The research makes the functions of backup relays more legible and hierarchical.New methods to calculate the settings of ground distance relay are proposed. To consider the effects of zero-sequence coupling on the grounding distance relay settings completely, a simple and applicable method to calculate the zero-sequence current compensation coefficient is proposed. A systemic method based on detecting impedance is proposed to calculate the settings of ground distance relay to overcome the shortages of all current setting calculation methods. The proposed methods are more applicable and the relay settings calculated based on the methods are more accurate. At the same time, a scheme about adaptive coordination of distance relays based on restriction conditions is discussed.On the aspect of coordination automation and intelligence technology, a method for automatic adjustment of relay coordination of transmission line protection based on sensitivity constraints is proposed. The method is implemented with two adjustment steps by introducing the concepts of the reset relay sensitivity constraint, remote backup relay sensitivity constraint and remote backup relay sensitivity transfer constraint. The relay coordination programme based on the method can adjust relay settings automatically to replace the protection engineers’ work. At the same time, an approach for coordination sequence optimization is presented to guarantee the stability of relay settings in protection relay systems.The off-line mode and on-line mode of relay coordination are analyzed, and the integral framework and some key technologies are discussed. Performance of relay setting determined in the modes of off-line and on-line based on an existing power system is discussed in detail. It is show from the analysis that it will be very significative to achieve on-line relay coordination for improve the performance of protective devices.The diversity and regionality of relay coordination bring a bad effect on the development and extension of relay coordination software. To eliminate the effect, the universality of relay coordination software is deeply studied from the aspects of power system operating conditions combination, step relay setting calculation, protective device setting calculation and relay setting listing. A universal scheme of operating conditions combination based on selecting principles is proposed, while the universal scheme of step relay settings calculation based on user-defined principles is presented. At the same time, the implementation of universal step relay settings calculation software module is introduced.An approach to evaluate the vulnerability of relay protection system for transmission lines is proposed. The probability model of relay protection system unintended operation is established from the aspects of protective device and relay settings based on the characteristics of its functions composition, and the effect on power system reliable operation brought by the unintended operation of relay protection system is quantified in the form of load loss. The integrative index called vulnerability index is presented based on the probability and damage degree of relay protection system unintended operation. The index can reflect the vulnerable region of protection system very well.To take full advantage of more nodes information for the identification of faulted primary device, a wide area relay protection algorithm based on direction comparison is proposed, and the wide area protection system based on the algorithm adopts the configuration based on power substation. The Primary Devices/Direction Element associated matrices for primary devices in substation and transmission lines connected different substations are created separately according to the bus configurations and direction elements positions in power plant or substations. When a fault occurs in power network, Primary Devices/Fault Direction associated matrices are formed based on the fault direction indicated by direction elements and Primary Devices/Direction Element associated matrices, and then the faulted primary device is identified based on the above information.更多还原