智能电网环境下电力系统保护新技术的研究与探讨

发布时间：2018-06-21 00:01

本文选题：超导限流器 + 超导电缆　；参考：《东南大学》2015年博士论文

【摘要】：随着我国智能电网的飞速发展,新设备和新技术的应用日新月异。超导限流器、超导电缆作为新设备的标杆在国家电网已有了示范应用,在稳态运行时能有效提高电网运行的经济性,在故障时能降低短路容量提高电网运行的安全性。分布式电源作为可再生能源重要的应用途径目前处于全面建设阶段,促进了低碳电力系统的发展。高级量测技术是智能电网的基础技术,其中光纤传感技术具有抗电磁干扰能力强、损耗低、传输频带范围宽等优点,在电力系统信息测量领域取得了比较好的应用效果。通信技术是智能电网的基础,我国具有完全自主知识产权的北斗卫星导航通信系统,可以在农村电力系统信息监控、电力线路巡监系统等领域具有良好的应用前景。智能电网环境下新设备和新技术的应用对电网运行提出了新的挑战。电力系统继电保护是电力系统安全运行的重要保障。超导限流器、超导电缆作为智能电网应用的新设备,在给电网运行带来优点的同时,也对电力系统常规继电保护产生了重要影响,比如由于超导电缆的特殊电气特性导致保护误动和拒动。分布式能源接入配电网是绿色能源的主要应用形式,使得配电网成为多源配电网,原有的配电网电流保护和距离保护已经不能适应多源配电网安全运行要求,需要寻求新的解决手段。光纤传感新技术需要适应和满足电力系统设备保护所需信息的特殊性,比如抗干扰能力强、测量精度高、实时性要求高等特点。北斗卫星导航新技术信息传送能力不够强,而电力系统保护和监测需要大量信息,如何将两者特性进行有效融合,是北斗在电力系统应用需要解决的重要问题。论文以智能电网环境下新设备和新技术的应用为背景,以电力系统保护为关键点,开展了以下研究工作：1、针对超导限流器、超导电缆新设备,研究了新设备投入电网运行时对电流保护的影响,并提出了可行的整定配置方法。论文首先从理论角度讨论了超导电缆和超导限流器在分别投入到线路对三段式电流保护和零序电流保护的影响；然后在超导电缆和超导限流器联合投入后分析了对三段式电流保护的影响,得到一般情况下限时速断保护需要重新整定、定时限过电流保护影响很小的结论,并研究了三段式电流整定方法。随后又分析了对于零序电流保护的影响,发现联合投入后改变了线路零序网络结构,使得零序电流保护的Ⅰ段、Ⅱ段保护的保护范围减少,需要对其动作整定值重新整定,并研究了零序电流保护整定方法。2、针对超导限流器、超导电缆联合投入,研究了其对距离保护的影响,并提出了可行的整定配置方法。论文首先对于三段式距离保护发现由于超导电缆的单位电容较大,超导限流器其电阻较大,其阻抗特性与常规线路的阻抗特性不同,会导致距离Ⅰ段、Ⅱ段保护的保护范围缩小引起保护拒动,并研究了三段式距离整定方法。然后对于工频变化量距离保护发现设备联合投入后,当线路发生正向故障时会导致保护范围变小引起保护拒动,当发生反向故障时,由于超导电缆的容性电抗相对于感性阻抗要大得多导致电流反向,引起保护误动。并从超导电缆长度选取和整定值配置两个角度提出了解决方案。3、针对分布式新能源,研究了分布式电源接入配网后对电流保护的影响,结合超导限流器的应用,研究了应用超导限流器有效减轻分布式电源接入的不利影响,提出了超导限流器和电流整定协调解决方案,并确定了分布式能源的最大允许接入容量。首先论文针对反时限电流保护,将超导限流器装置应用于配电网络,在分析分布式电源接入对反时限保护的影响机制的基础上,所提出的超导限流器的最小参数配置解决了配电网反时限保护的协调问题。然后针对三段式电流保护,提出选取超导限流器常导状态(故障)下阻抗及修改保护定值的方法,在考虑系统和分布式电源运行方式变化的前提下,很好地保证了保护的选择性。针对分布式电源接入的准入容量分析和研究,发现应用超导限流器可以有效提高DG的准入容量,并且分布式电源的接入位置不同会对接入超导限流器之后的准入容量产生较大的影响。4、针对光纤传感新技术,提出了一种基于分布式光纤传感技术的变压器绕组变形监测方法。论文首先根据光的电磁波动理论,从理论上分析了光纤弯曲传感器的工作原理。然后根据光的波动理论根据实验来证实了光时域反射(OTDR)传感系统的可行性。分析了通过分析光接收机接受到的光功率信号的大小与时间来判断变压器绕组的变形及变形发生的位置的精度。通过实验系统,发现论文所提方法可以实时监测到变压器绕组轻微机械变形量与变形发生的位置,具有的灵敏度高、抗电磁干扰、绝缘性好等优点,提高了变压器保护的可靠性。5、针对北斗卫星导航通信技术,分析了北斗通信系统应用于电力系统常规信道破坏时作为通信系统第三道防线的可行性,并解决了故障过程中北斗信息通道有限导致的电力系统保护信息选择和排队等问题,提高了电力系统保护信息传输通道的安全性。论文首先对北斗导航通信系统进行详细的介绍,并对北斗通信与光纤通信等其他通信信道进行比较,分析了北斗通信系统应用于电力系统常规信道破坏时作为通信系统第三道防线的可行性。然后分析应用过程中需要克服的单次通信数据量小、通信时间间隔大、没有可靠的数据传输机制等问题,并提出了可行的解决方案。随后针对故障过程中北斗信息通道有限而故障信息需要集中发生而产生的排队延时问题,构建了优先级队列的算法解决了并行数据接收的问题。最后针对故障信息同时大量输送问题,定义了保护重要性指标和优先级,保障了电网继电保护信息等实时性要求高的数据的接收问题。
[Abstract]:With the rapid development of smart grid in China, the application of new equipment and new technology is changing rapidly. Superconducting current limiter, superconducting cable, as a benchmark for new equipment, has been demonstrated and applied in national power grid. It can effectively improve the economy of power grid operation in steady state operation and reduce the short circuit capacity to improve the security of power grid operation in the case of failure. As an important application way of renewable energy, cloth power supply is at the stage of comprehensive construction, which promotes the development of low carbon power system. Advanced measurement technology is the basic technology of smart grid. The optical fiber sensing technology has the advantages of strong anti electromagnetic interference ability, low loss and wide transmission band range, and it is used in the power system information measurement collar. The communication technology is the foundation of the smart grid, and the Beidou satellite navigation communication system with complete independent intellectual property rights in China has a good application prospect in the fields of rural power system information monitoring, power line inspection system and other fields. The power system relay protection is a new challenge. The power system relay protection is an important guarantee for the safe operation of the power system. Superconducting current limiter, superconducting cable as a new device for the application of the smart grid, has brought the advantages to the operation of the power grid, and also has an important influence on the conventional relay protection of the power system, for example, due to the special superconducting cable. Electrical characteristics lead to protection misoperation and rejection. Distributed energy access distribution network is the main application form of green energy, which makes the distribution network become multi source distribution network. The original distribution network current protection and distance protection are unable to adapt to the security operation requirements of multi source distribution network, and need to seek new solutions. The need of new optical fiber sensing technology needs. In order to adapt and satisfy the particularity of the information needed for the protection of power system equipment, such as strong anti-interference ability, high precision and high real-time requirement, the information transmission ability of the new technology of the Beidou satellite navigation technology is not strong enough, and the protection and monitoring of power system need a lot of information. How to effectively fuse the two characteristics is the Beidou in the power system In the background of the application of new equipment and new technology in the smart grid environment and the key point of the power system protection, the following research work has been carried out in this paper. 1, the new equipment of superconducting current limiter and superconducting cable is used to study the effect of the new equipment on the current protection of the electric network, and the feasibility of the new equipment is proposed. In this paper, the influence of superconducting cable and superconducting current limiter on three stage current protection and zero sequence current protection is discussed from the theoretical point of view. After the joint input of superconducting cable and superconducting current limiter, the influence on the three stage current protection is analyzed, and the time limit speed break in the general case is obtained. The protection needs to be reset, the time limit over current protection is very small, and the three stage current setting method is studied. After that, the influence of the zero sequence current protection is analyzed. It is found that the zero sequence network structure has been changed after the joint investment, which makes the protection range of zero sequence current protection reduced, and it needs to be used for the protection of zero sequence current protection. The action setting value is rearranged and the zero sequence current protection setting method.2 is studied. In view of the superconducting current limiter and the superconducting cable joint input, the influence on the distance protection is studied, and the feasible setting method is put forward. First, the paper has found that the unit capacitance of the superconducting cable is larger and the superconducting current limiter is found for the three section distance protection. Its resistance is large and its impedance characteristic is different from the impedance characteristic of conventional line, which will lead to distance I. The protection range of the second section protection is reduced and the three section distance setting method is studied. After the joint input of the frequency range protection discovery equipment, the protection model will be caused when the line has a positive fault. In the case of reverse fault, when the reverse fault occurs, the capacitive reactance of the superconducting cable is much larger than the inductive impedance and causes the protection misoperation. The solution.3 is proposed from the two angles of the selection of the length of the superconducting cable and the configuration of the setting value, and the distributed power access matching is studied for the distributed new energy. After the effect of the network on the current protection, combined with the application of the superconducting current limiter, the adverse effects of the application of the superconducting current limiter to reduce the access of the distributed power supply are studied. The superconducting current limiter and the current setting coordination solution are proposed, and the maximum allowable access capacity of the distributed energy is determined. The superconducting current limiter is applied to the distribution network. On the basis of the analysis of the influence mechanism of the distributed power access on the anti time limit protection, the minimum parameter configuration of the superconducting current limiter is proposed to solve the coordination problem of the inverse time protection of the distribution network. Then, the constant conduction state (fault) of the superconducting current limiter is selected for the three stage current protection. Under the premise of changing the operating mode of the system and the distributed power, the method of lower impedance and the fixed value modification guarantee the selectivity of the protection very well. In view of the access capacity analysis and research of the distributed power supply, it is found that the application of the superconducting limiter can effectively improve the access capacity of DG and the access position of the distributed power supply. The difference will have a great influence on the access capacity of the superconducting current limiter. In view of the new optical fiber sensing technology, a new method of transformer winding deformation monitoring based on the distributed optical fiber sensing technology is proposed. Firstly, according to the electromagnetic wave theory of light, the working principle of the optical fiber bending sensor is analyzed theoretically. Then, the working principle of the optical fiber bending sensor is analyzed in theory. According to the wave theory of light, the feasibility of the optical time domain reflection (OTDR) sensing system is verified according to the experiment. The accuracy of the location of the deformation and deformation of the transformer winding is determined by analyzing the size and time of the light power signal received by the optical receiver. With the advantages of high sensitivity, resistance to electromagnetic interference and good insulation, the reliability.5 of transformer protection is improved. According to the Beidou satellite navigation communication technology, the Beidou communication system is used as the third channel of the communication system when the conventional channel is destroyed in the power system. The feasibility of the line is solved, and the information selection and queuing of the power system protection caused by the limited information channel of the dipper is solved. The security of the transmission channel of the power system protection is improved. First, the paper introduces the Beidou navigation communication system in detail, and other communication letters, such as Beidou communication and optical fiber communication. By comparing the channel, the feasibility of the Beidou communication system to be used as the third line of the communication system when the power system is destroyed by the conventional channel is analyzed. Then the problems of small amount of single communication data, large communication time interval and no reliable data transmission mechanism in the application process are analyzed, and a feasible solution is put forward. Then, in order to solve the problem of queuing delay caused by the limited information channel of the dipper and the centralized fault information in the process of fault, a priority queue algorithm is constructed to solve the problem of parallel data reception. Finally, the importance index and priority of the protection are defined for the problem of the fault information at the same time, and the power grid relay is guaranteed. Protection of information and so on.
【学位授予单位】：东南大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TM77

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