电力线路在线巡视监测及故障精确定位的研究

发布时间：2018-02-20 23:35

本文关键词： 配电线路输电线路行波故障定位在线巡视最优配置互感器传变特性　出处：《华中科技大学》2014年博士论文　论文类型：学位论文

【摘要】：随着智能电网建设的推进,超/特高压远距离大容量输电线路数量不断增加,配电网负荷密度不断提高,电力线路作为电力系统运行的大动脉,其安全可靠运行成为电力系统输电和配电运行管理环节的重中之重,是确保电力供应安全性和可靠性的关键所在,是实现我国发展智能电网初衷的重要基础。为提高电力线路安全运行水平,目前的主要技术手段包括线路发生故障后的故障精确定位和线路发生故障前的电力线路在线巡视监测两方面内容。线路发生故障后的故障精确定位是保障故障线路快速修复和非故障区域供电快速恢复的关键技术。基于故障暂态行波的定位方法受TA饱和、故障电阻、故障类型及系统运行方式影响小,定位精度高,一直是研究的热点,并已广泛应用于输电系统中,但其在定位可靠性方面还有待进一步提高。同时,相较于输电线路故障定位,配电网故障自动定位技术的概念更为宽泛,实现上也更为复杂,主要包括故障选线、区段定位和故障测距。非有效接地配电网的故障选线和单相接地故障区段定位一直是电力系统中的一大难题。由于配电网结构复杂,分支多等特点,输电线路行波故障测距方法也不能直接应用于配电网故障测距中。需要研究基于故障暂态行波的配电网故障定位新方法。线路发生故障前的电力线路在线巡视监测可及时获取电力线路运行状态和环境信息,发现电力线路及其设备的异常状态与缺陷,以便运维人员提前做好设备检修工作。现有的巡视监测方法主要包括人工巡线、直升机巡线、基于巡线机器人巡线,以及辅助的状态在线监测方法。这些方法还不能满足工程现场需求,实现电力线路全景状态的在线实时监视和远程操控巡视,不能实现智能预警。为克服以上问题,本文重点研究了基于故障暂态行波的中压配电网故障选线、区段定位和故障测距以及交流输电线路故障测距方法,同时对基于输电线路光纤复合架空地线(OPGW)光纤通信的输电线路在线巡视监测新方法展开研究。具体内容如下：首先,对基于模量行波到达时间差的单端行波故障测距方法进行了改进,并将其应用于配电网单相接地故障测距中。通过分析发现选择小波变换合适大尺度下模极大值标定波头到达时刻可使零模检测波速度更稳定,并分析得出可利用波头到达时刻频率分量与故障距离的关系、零模波速度与频率的关系构造迭代公式提取零模检测波速度,提出的迭代算法提高了零模波速度求取的准确性及抗干扰能力。基于此,提出基于模量行波传输时间差的配电网单相接地故障双端定位方法,理论分析和仿真结果显示该方法无需全网精确时间同步,不仅可定位主干线路故障点,还可定位分支线路故障点。其次,对基于单相相电流行波的配电网故障选线和区段定位方法进行了研究,针对仅安装A、C两相电流互感器这一配电网工程现场情况,通过分析相电流暂态行波在母线处的折反射特性,提出基于本地单相相电流暂态行波比幅比相的预选线算法。结合相电流行波的传输特性,通过分析比较联络线两端母线处的预选线结果实现区段定位。同时考虑到馈线终端(FTU)大多配套安装线电压互感器,提出利用母线处的相电流行波、馈线末端的线电压行波实现故障测距。所提定位方案可统一实现配电网中的故障选线、区段定位与故障测距。第三,为提高输电线路行波故障测距的可靠性,基于特征非奇异集,提出了一种输电线路网络式行波定位单元优化配置方法及相应的网络式行波定位算法。利用Dijkstra算法将电力网拓扑图等效为最大非奇异集,进而得出每条线路的特征非奇异集。结合行波定位原理,利用特征集形成优化配置方案。同时研究了基于最大非奇异集的网络式行波定位算法。所提出的方法可保证在行波定位单元安装数量最少时,即使断路器状态未知也可定位任意线路上的故障位置,能有效提高网络式行波定位方法的可靠性和实用性。第四,在时域中对电磁式互感器传变特性的分析发现其暂态响应存在自由振荡过程,通过分析这一过程对行波故障定位算法的影响得出行波定位方法的采样率必须保证在1MHz以上才可获得理想的定位精度,且为保证选取的小波分解尺度最佳,连续小波变换(CWT)相较离散小波变换(DWT)更加适合定位行波波头到达时刻。第五,分析了输电线路巡视任务及必要的状态监测功能,结合最新的OPGW接续引下技术以及以太无源光网络(EPON)技术,提出光纤通信网的组网方案,既而给出由逐塔配置的杆塔终端、EPON以及后台监控主机构成的架空线路在线巡视监测系统方案。据此研发了相应的样机并进行了试运行。同时还基于网孔分析法对OPGW故障电流分布特性进行了分析,既而提出基于相邻杆塔处OPGW故障电流相位比较的故障测距算法。所开发的系统可实现输电线路的自动定时智能巡视和人工远程操控巡视。所提出的算法可实现精确到塔距的故障测距。最后,对全文工作与创新点进行了总结,并对后续研究工作进行了展望。
[Abstract]:With the smart grid construction, the number of EHV / UHV long distance transmission line increases, the distribution network load density increasing, the power line as the main artery of the operation of power system, the safe and reliable operation has become the priority among priorities of the transmission and distribution of power system operation and management, is the key to ensure the safety of electricity supply and reliability, is an important foundation to realize the original intention of the development of smart grid in China.
In order to improve the safe operation level of power lines, the main technical means include two aspects: the precise location of the fault after the fault occurs, and the on-line inspection of the power line before the line fails.
The accurate fault location of fault line after is the key technology to ensure the rapid repair of fault line and non fault area power supply fast recovery. Positioning method of transient traveling wave based on TA saturation, fault resistance, fault type and operation mode of the system is small, high precision, has been the focus of research, and has been widely used in power transmission in the system, but the positioning reliability is to be further improved. At the same time, compared to the fault location of the transmission line, the concept of automatic positioning technology of distribution network fault is broader, implementation is more complex, mainly including fault detection, location and fault location. Ground fault location in non effective earthed distribution network fault line selection and fault phase is always a big problem in the power system. Because the distribution network structure is complex, many branches, transmission line traveling wave fault location is not straight A new method for fault location of distribution network based on fault transient traveling wave is needed to be used in fault location of distribution network.
The power line fault occurred before the online patrol monitoring can timely access to the power line running state and environmental information, abnormal state and defects of power lines and equipment, operation and maintenance personnel to do maintenance work. The existing methods of monitoring inspections including artificial patrol line, helicopter patrol line, line patrol inspection robot based on and the auxiliary state on-line monitoring method. These methods can not meet the engineering site requirements, implementation of state power line panorama real-time online monitoring and remote control inspections, not intelligent warning.
In order to overcome the above problems, this paper focuses on the research of fault transient traveling wave fault line selection based on medium voltage distribution network, location and fault location and AC transmission line fault location method, at the same time of OPGW of transmission line based on transmission line (OPGW) optical fiber communication is researched. A new method of monitoring inspection as follows:
First of all, the single terminal traveling wave fault location method based on traveling wave arrival time difference modulus was improved and applied to the single-phase grounding fault location. Through the analysis of selection of wavelet transform modulus maxima suitable large scale calibration of the arrival time of traveling wave velocity to zero mode detection is more stable, and analysis it can use the wave arrival time between frequency components and the fault distance, the relationship between constructing iterative formula of zero mode wave speed and the frequency of the detected zero mode wave velocity, an iterative algorithm is proposed to improve the accuracy of zero mode wave and calculating speed and anti-jamming ability. Based on this, the grounding fault location method of single phase modulus of the traveling wave transmission distribution network based on time difference, theoretical analysis and simulation results show that this method does not require the whole network precision time synchronization, positioning can not only trunk line fault points, but also to locate branch line the road A barrier point.
Secondly, the single phase power pop wave distribution network fault line selection and location based methods are studied, aiming at the installation of A, C phase current transformer the power distribution network engineering field, the characteristics of catadioptric in busbar transient traveling through the analysis of the phase current, based on local single phase current transient traveling wave comparison of the amplitude and phase algorithm. Combined with the pre line transmission characteristics of phase current traveling wave, pre line through the analysis and comparison of contact line terminal the location. At the same time taking into account the feeder terminal unit (FTU) are supporting the installation of line voltage transformer, the bus phase current, line voltage traveling wave feeder terminal the implementation of fault location. The proposed localization scheme can be realized in the distribution network fault line selection and fault location, location.
Third, in order to improve the reliability of traveling wave fault location of transmission line, based on the characteristics of non singular set, proposes a network transmission line fault location unit optimization configuration method and network fault location. Corresponding algorithm uses Dijkstra algorithm to power network topology is equivalent to the non singular set, then each line of non characteristic the singular set. Combined with the principle of traveling wave location, using the feature set form configuration optimization scheme. At the same time on the network fault location algorithm based on the maximum non singular set. The proposed method can ensure the minimum number of traveling wave location unit is installed, even unknown circuit breaker status can also locate any fault location on the line, can effectively improve the the reliability and practicability of the network type traveling wave location method.
Fourth, in the time domain of electromagnetic transformer analysis of transient response characteristics that the existence of free oscillation process, through the analysis of the influence of the process of traveling wave fault location algorithm of traveling wave location method of sampling rate to ensure the positioning accuracy can be obtained in the above 1MHz, and to ensure the selection of wavelet decomposition scale the best, the continuous wavelet transform (CWT) compared with the discrete wavelet transform (DWT) is more suitable for positioning the head of traveling wave arrival time.
Fifth, analysis of the transmission line inspection tasks and necessary condition monitoring function, combined with the latest OPGW connection under technology and Ethernet passive optical network (EPON) technology, the networking scheme of optical fiber communication network, which is given by the terminal tower by tower configuration, overhead lines EPON and host monitors online inspection form design of monitoring system. The development of the prototype and the trial operation. Also based on the mesh analysis of the OPGW fault current distribution characteristics method, then put forward the fault location algorithm of adjacent towers at the OPGW fault current based on phase. The system can achieve the transmission line automatic timing and remote artificial intelligent inspection control of inspection. The proposed algorithm can achieve accurate fault location from the tower.
Finally, the full text work and innovation point are summarized, and the follow-up research work is prospected.

【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM75

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