实测数据环境下的输电线路行波故障测距关键技术研究

发布时间：2018-04-20 12:41

本文选题：输电线路 + 故障测距　；参考：《哈尔滨工业大学》2014年博士论文

【摘要】：行波测距技术是确定电力线路故障位置的重要手段。实际应用中的行波测距装置或方法,尚存在自动化程度低、时问同步和通信要求高、数据采信影响结果可靠性等问题。本文针对实测环境,对故障录波数据筛选、行波波头标定、测距算法、历史案例复用、装置优化布点等关键技术问题展开深入研究,以期达到提高实测数据采信度并进一步提升输电线路行波故障测距效果的目的。针对多通道电流行波录波数据中难以筛选出有效故障录波的问题,提出了带条件约束的半监督聚类筛选方法。通过构造广义电流模量降维并提取特征,考虑相邻样本的时间邻域约束和少量已知类别历史样本的提示作用进行聚类。实际变电站故障录波数据测试表明该方法具有较高的正确检出率。针对实测行波波头自动标定可靠性不高的问题,提出了基于Hough变换直线检测的波头标定方法。通过分析故障电流行波传播规律、通道选取方式和实测波形图像特征,利用Hough变换于合理视窗内检测直线,根据幅值、斜率特征排除对侧母线和本侧健全线反射波的干扰。方法具有抗噪能力强、对波形局部缺损不敏感等特点。针对当前单、双端测距存在的主要技术局限,提出了不同应用条件下的三种测距算法。在故障线两侧母线间存在健全通路的条件下,提出利用故障线和健全线主导波头时差信息的单端测距,无需对端通讯和时钟同步,波头易标定,近端故障无死区。对链式拓扑结构,分析了下级线路故障时本级线路单端测距直接延拓的条件,对不满足直接延拓条件的,提出利用两个时窗内关联波头到达时刻信息构造算法实现单端测距的间接延拓,拓宽了单端测距的范围。对双端测距,利用两侧行波到达时序配对关系构造强弱故障模态的判据,进而分别提出两种模态下的双端协同测距方法,能够规避双侧时钟失步和单端波头误标所致的误测风险。为了提升测距计算结果与工程呼称值的吻合度,提出了一种可跨库或跨平台复用历史案例的智能测距方法。故障具有偶发性和一定程度的复发性,利用当前故障与少量宝贵历史案例的相似性合理复用算法参数或结果应利于测距效果的改善。据此思路,通过构建故障特征,测距参数,测距结论三元组形式的案例库,利用归一化波形的首波峰占比、近似熵、Hu氏不变矩特征匹配案例库的波头标定参数并判别故障复发性。对复发性故障直接复用历史结论,对高度相似的非复发故障,复用工况最匹配案例的距离折算系数,有助于缩小线路故障排查范围。为了提升测距系统在电网不同发展阶段的适应性,构建了电流行波测距装置的优化布点策略。在数学化描述电网故障电流行波可测性的基础上,建立计及既有配置状态和可测性约束的行波测距装置拓展布点规划模型,进而基于模型的最优静态解,以每退出一套装置导致减少的可测线长最小为依据,确定动态装设顺序,从而兼顾测距系统的经济性和覆盖范围。
[Abstract]:Traveling wave distance measurement is an important means to determine the fault location of power lines. There are still some problems in the practical application of traveling wave distance measuring device or method, such as low degree of automation, high demand for synchronization and communication, and reliability of data acquisition, and so on. In order to improve the reliability of measured data and further improve the effect of fault location of transmission line traveling wave fault, the key technical problems, such as historical case reuse, device optimization, and other key technical problems are studied.
In view of the problem that it is difficult to screen out effective fault recording in the data of multi channel current traveling wave recording, a semi supervised clustering method with conditional constraints is proposed. By constructing the generalized current modulus to reduce the dimension and extracting the features, the clustering of the neighborhood constraints of adjacent samples and the hint of a small number of known class history samples is taken into consideration. The test of substation fault recording data shows that the method has a high correct detection rate.
In view of the problem that the reliability of the measured wave head automatic calibration is not high, a wave head calibration method based on the Hough transformation line detection is proposed. By analyzing the propagation law of the traveling wave, the way of the channel selection and the characteristics of the measured waveform, Hough is used to detect the straight line in a reasonable window, and the side mother is excluded according to the amplitude and the slope characteristic. The method has the characteristics of strong anti noise ability and insensitive to the local defect of the waveform.
In view of the main technical limitations of current single and double end range finding, three ranging algorithms under different application conditions are proposed. Under the condition of sound paths between two bus lines on both sides of the fault line, a single end range finding using fault lines and a sound leading wave head time difference information is proposed, without the need for the end communication and clock synchronization, the wave head easy to calibrate, and the near end. For the chain topology, the condition of direct extension of the single terminal distance measurement at the level of the lower level line is analyzed. The indirect extension of the single end distance measurement is realized by using the information construction algorithm of the arrival time of the associated wave head in two windows. The range of the single end range finding is widened. The criterion of strong and weak fault mode is constructed by the arrival time sequence pairing relationship between two traveling waves, and then the two terminal cooperative ranging method under two modes is proposed respectively, which can avoid the risk of mismeasurement caused by bilateral clock loss and single end wave head error.
In order to improve the agreement between the results of distance measurement and the call value of the engineering, an intelligent distance measurement method which can reuse history cases across the library or cross platform is proposed. The fault has the occasional and a certain degree of recurrence, and the reasonable reuse of the algorithm parameters or results using the similarity of the current fault and a small number of valuable historical cases should be beneficial to the distance measurement. According to this idea, a case base of three tuples in the form of fault features, ranging parameters and ranging conclusions is constructed, using the first wave peak occupation ratio of the normalized waveform, the approximate entropy, the Hu moment invariant feature matching the wave head of the case library to calibrate the parameters and distinguish the fault recurrence. Failure, the conversion coefficient of the best matching case is helpful to reduce the scope of line fault detection.
In order to improve the adaptability of the distance measuring system at different stages of the development of the power grid, the optimization layout strategy of the current traveling wave distance measuring device is constructed. On the basis of the mathematical description of the detteability of the fault current of the power grid, a traveling wave ranging layout model is built up with the existing configuration state and measurability constraints, and then the model is based on the model. The optimal static solution is based on the minimum length of the measurable line that is reduced by each set of devices, and the order of dynamic loading is determined, so that the economy and coverage of the distance measuring system are taken into account.

【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM75

【参考文献】