【作者】 李盼盼；

【导师】 潘贞存； 陈青；

【作者基本信息】 山东大学 ， 电力系统及其自动化， 2010， 硕士

【摘要】 近年来分布式发电技术(Distribution Generation:DG)得到了快速的发展,随着DG的并网运行,改变了配网原有的短路电流流向,导致原有馈线保护出现灵敏度降低、拒动、误动等问题,这给配网故障的检测与隔离带来多方面的问题,因此开展相关方面的研究,寻找新的解决问题的途径,提出相应的对策是十分必要的,对于DG在配网中的发展和推广有着重要的意义。本文在总结和借鉴前人研究工作的基础上,通过对DG接入配网后对保护影响的定性分析,发现当发生故障时,故障点与DG之间不同的位置关系,对线路保护的影响会有所不同。通过分析可知：当DG上游发生故障时,故障馈线保护所感受到的故障电流与只与系统侧电源有关,但由于DG所引起的反向电流如果过大,有可能引起故障点与DG之间馈线保护的误动；DG下游发生故障时,DG上游的馈线保护感受到的短路电流将会根据DG接入的位置和容量的改变,受到不同程度的影响。当故障发生在DG接入馈线时,对DG下游保护无影响；当故障发生在DG下游馈线时,下游保护流过的短路电流将受DG助增电流的影响而增大。基于以上的结论对电流保护进行了改进配置,并提出了三种应对DG并网后配网故障检测与隔离的方案,包括重合器-分段器配合模式的改进方案、基于通信的分布式纵联与主从式区域纵联方案,并分析了其各自的特点和适用范围。重点对其中的主从式区域纵联方案进行了深入研究,包括对故障检测与隔离算法的研究、相应软硬件装置的设计与实现和通信方案的研究等。主从式区域纵联方案在每一个分段开关处配备保护从机,依靠其内部的故障方向元件,测量其安装点处的故障方向,当配网系统故障后,主机下发命令收集从机故障方向信息,之后通过故障检测与隔离算法对所收集的信息进行运算处理,得出最终的故障区段和需要跳开的开关信息,并下发跳闸指令,完成故障的隔离。其中方向元件的可靠动作、故障检测与隔离算法的合理设计和通信的快速可靠是方案实现的关键。因此在实现方案之前首先通过对系统的需求进行分析,构建出了方案基本的结构框架,并重点针对系统的核心算法进行了各种情况的讨论,包括故障检测算法、故障隔离算法、系统结构发生变化时的处理措施和系统信息不完备情况的故障处理分析,在此基础上通过各功能模块的构建实现,开发完成了主机监控系统；故障方向的检测是通过分段开关处的保护从机实现的,其中的故障方向元件采用故障分量和90°接线原理,保证了方向元件的可靠性,该从机装置是为实现本方案单独开发的软硬兼备的保护装置,很好的满足了对故障检测的需要,并且具有友好的人机交互界面和组网功能。在配网故障的处理过程中,主机和从机通过光纤通信网络进行信息的交互。本文制定了详细的通信策略和搭建了可靠的通信平台,保证了系统通信的快速实现。最后通过搭建现场实验平台和制定相应的测试方案,完成了对整套系统方案的测试工作,从而验证了主从式区域纵联方案在分布式电源接入后实现正确、快速的配网故障检测与隔离的可行性。更多还原

【Abstract】 Distribution generation (DG) technology has been rapidly developed in recent years. The direction and distribution of the short circuit current in distribution power system has changed a lot due to the introduction of DG, as a result, the existing feeder protection there may be reduced sensitivity, tripping failure, malfunction, and so on, which gives distribution network fault detection and isolation brought about many problems. Therefore it is necessary to carry out related research, find new ways to solve problems and put forward countermeasures, and of great significance for the distribution network with DG in the development and promotion.On the basis of previous research, after qualitative analyzing the influence of distribution networks with DG on the protection, we found the impact of the line protection will be different, when the relationship of the fault point and DG position has changed. As following:When DG upstream failure, the fault current flowing through the fault feeder protection is only relevant to the system power, but if the reverse current caused by the DG is too large, it may lead malfunction of the feeder protection between fault point and DG. When the fault occurred in the DG access feeder, the protection have no effect on the DG downstream. When the fault occurred in the feeder of DG downstream, the fault current flowing through the protection will be increased by the help of DG. Based on the above conclusions, we improved the current protection configuration, and integrated it into the distribution network under different fault detection and isolation scheme, then put forward three kinds of fault detection and isolation schemes to response the distribution network with DG, including Recloser-Sectionalizer model improvement program, Distributed Pilot program and Master-Slave Regional Pilot program based on communications, and analyzed characteristics and scope of their. Focus on the master-slave regional pilot program conducted in-depth research, including fault detection and isolation algorithm, the design and implementation of device and communications programs. Every switch in the distribution power system is equipped with slave protection device (SPD)by Master-Slave Regional Pilot program. Each SPD has a fault direction element inside, which measures the voltage and current of its position and determines the fault direction. When the distribution power systerm is failure, the fault direction information are collected through the communication system, and used by fault detection and isolation algorithm. The reliable action of fault direction element, reasonably design of fault detection and isolation algorithm and fast communication is the key to program implementation. We analyzed the program requirements on the system before scheme implementation, constructed the basic structural framework, and focusing on core of the system algorithm discussed various situations, including fault detection algorithms, fault isolation algorithms, the method to deal with system structure change and the processing with incomplete information. Through the construction and implementation of each functional module, we develop the host monitoring system. Fault direction detection is achieved by SPD, in which the fault direction element use fault component and 90°wiring principle to ensure the reliability. The slave device is developed for the implementation of the program with both hardware and software, better to meet the needs of fault detection, and has a friendly interactive interface and networking functions.In the processing of fault detection and isolation, master and slave device achieve the interaction of information by the optical fiber communication network. This paper developed a detailed communication strategy and built a reliable communications platform, to ensure the system communication quickly. Finally, we set up the test platform and developed the corresponding test program to complete the entire system testing, which examined the Feasibility that Master-Slave Regional Pilot program in the distribution network with DG could also correctly and rapidly accomplish the fault detection and isolation.更多还原