【作者】 李洪波；

【导师】 李永丽；

【作者基本信息】 天津大学 ， 电力系统及其自动化， 2009， 硕士

【摘要】 高压直流输电技术由于其输送容量大、线路损耗小、不存在同步稳定问题、控制灵活快速等优势,在我国输电系统中得到了越来越多的应用,在“西电东送”、“北电南送”工程中起着重要作用。直流输电线路距离往往上千公里,线路越长、发生故障的概率越高,同时查找故障点的难度也越大。因此,快速准确的确定故障点具有重要意义。目前,高压直流输电系统仅仅依靠行波测距装置进行故障定位,但当故障点和对侧母线反射系数较小,例如在高阻接地故障时可能会出现测距不准或行波测距装置不启动的情况。因此,寻找一种新的测距方法对实际工程有着重要意义。时域测距算法从线路的小损耗模型出发,无须考虑频率等因素,根据从线路两端数据计算得到的沿线电压在故障点处相等的原理识别故障点,更加适合于直流输电系统。本文研究了如何由直流线路的几何参数计算其模参数的方法,对时域故障测距原理进行了仿真验证。提出了对参数不敏感的基于遗传算法的故障测距模型,解决了线路参数多变及无法准确获得的问题。通过对实际现场数据的分析,提出了利用极电流实现同一换流站内的数据对时、利用遗传算法实现线路两端换流站的数据对时的方法。并通过仿真数据和实际直流系统故障录波数据验证了基于遗传算法的测距方法和数据对时方法具有良好的效果,完全符合现场对测距精度的要求。依照通用编程规范和模块化编程思想,利用MATLAB编写生成了标准的COM测距组件,有利于程序的移植调用和后期的软件调试。根据不同需要,分别编制了6种不同的测距组件,以方便用户根据实际情况选择使用,提高了测距计算速度。更多还原

【Abstract】 Because of its large transmission capacity, low line loss, no synchronism stability problems, flexible control, HVDC power transmission technology has been applied more and more in power transmission system in our country. It plays an important role in the projects of transmission power from west to east and north to south. Generally, the HVDC transmission lines are hundreds of kilometers. The longer the lines are, the greater probability of line fault is, and the more difficult it will be to find the fault location. So, it is of great significance to determine the fault location rapidly and accurately.Now, the HVDC transmission system only has travelling wave fault location device. But in the case of small reflection coefficient of fault point or other end bus, such as high resistance grounding fault, the fault location maybe not correct or the device may not be started. So, it has important meaning to find a new method of fault location. Time domain fault location is based on the small loss model of transmission line, and doesn’t have to consider the factor of frequency. It is according to the principle that the voltages calculated from both end of the line are the same to identify the point of fault. So this method is more suitable for DC transmission system. On the basis of researching of the way of calculating mode parameters of transmission line form its geometric parameters, the feasibility of time domain fault location method is validated. A fault location model, which is based on the Genetic Algorithm and is non-sensitive to the line parameters, is presented.By analyzing the site data, proposes a way to correct times in one converter station using pole currents, and to correct times between the two ends of line using Genetic Algorithm. Simulation and site fault recording date test results have shown the effectiveness of these algorithms and that they were in accord with the accuracy requirements of fault location in site.In accordance with the modular programming ideas, standard COM components of fault location are generated using MATLAB language. It is convenient to transplantation and debugging. Six different components are generated according to different requirement. User can chose a proper one on the basis of actual situation to improve calculation speed.更多还原