【作者】 胡兵；

【导师】 尹春杰；

【作者基本信息】 山东大学 ， 控制科学与工程， 2011， 硕士

【摘要】 供电的可靠性、经济性和优质性是电力系统的三个重要方面[1]。单相接地故障是电力系统中最为常见的故障类型,为了提高供电的可靠性,我国6-35kV配电网大多采用小电流接地方式运行。由于小电流接地系统发生单相接地时故障电流小,因此接地选线问题至今未能得到很好地解决,影响了供电的可靠性。电能质量作为电力系统的一个重要方面,随着非线性负荷的增多,电能质量问题越来越受到供用电单位的重视,因此电能质量的在线监测就显得十分必要。本文设计的LLJ-JDS分布式小电流接地选线及电能质量在线监测系统,采用分布式网控架构,以32位DSP为硬件平台,将传统选线法与电容助增法相结合,就地选线与集中选线相结合,不仅有效地解决了小电流接地选线问题,而且兼顾了电能质量在线监测功能,满足了供用电部门的迫切需求,具有很好实用性和经济效益。本文首先介绍了小电流接地选线与电能质量监测问题的研究现状及相关标准。分析了中性点不接地和中性点经消弧线圈接地系统单相接地的故障特征,深入分析了电容器助增选线方法。详细介绍了电能质量监测装置的技术要求以及电能质量的基本算法。在此基础上,给出了LLJ-JDS系统的总体方案设计,并着重介绍了系统终端装置的硬件与软件设计。最后,结合系统的工程应用和型式试验情况,对LLJ-JDS系统进行了总结与展望。更多还原

【Abstract】 Reliability, economy and quality is three important aspects of power system. Single-phase ground faults are the most common faults in power system. In order to improve the reliability of power supply, most 6～35kV distribution networks in China have been running in non-effective grounded mode. The current of ground fault is small, so the fault line selection problem has not been commendably solved, which affects the reliability of power supply. As an important aspect of power system, with the increasing of nonlinear loads, power quality problem has been more and more concerned by electric power departments and eletricity users, so it’s very necessary to monitort power quality online.This paper designs a system, named LLJ-JDS, which is a distributed network. The system, whose platform is 32 bits digital signal processor, combines traditional line selection methods and capacitors injection method, and combines local line selection and concentrated line selection. It not only solves the problem of fault line selection, but also achieves the purpose of power quality monitoring. The system meets the power providers and users’ urgent demands, so has good practicability and economic benefits.At the beginning of this thesis, the research status and related standards of fault line selection in non-effetive earthed system and power quality online analysis are introduced. Then, the characteristics during single phase ground fault in neutral-point ungrounded system and neutral-point earthed via petersen coil system are respectively analyzed, and capacitor injection method is put forward. Technology requirements and basic algorithm of power quality monitoring devices are described in detail. On this basis, overall design of the system is brought forward, and stress is laid on the hardware and software design of the system’s terminal. Finally, base on the situation of practical application and results of type testing, summery and prespect of LLJ-JDS system are proposed.更多还原