【作者】 叶国钢；

【导师】 黄民翔； 王康元； 朱雷鹤；

【作者基本信息】 浙江大学 ， 电气工程， 2011， 硕士

【摘要】 电能已经成为现代人们生活当中不可缺少的能源,电力系统的运行必须安全、可靠,这样才能保证供电的正常,直流电源系统作为变电站电力系统的保障,也就必须稳定可靠。直流系统的问题已成为变电站安全运行的主要问题之一。当直流系统发生异常时,极有可能引起继电保护、监控信号的不正常动作,甚至导致全所失电等不可预料的电网事故。本文简述了变电站直流电源系统的主要构成和直流系统的设计原则。对直流电源系统接地问题作了分析,这是造成直流电源系统误动作或拒动作的重要原因。同时,本文简要分析了直流系统中的断路器和熔断器的工作特性,指出了当前直流系统中级差配合的主要问题,并提出相应的选择原则和要求。最后,本文详细的介绍了接地监测方法的种类以及接地电阻的计算,并对比分析了几种方法的优缺点,确定了采用不平衡电桥和交流信号注入法相结合的绝缘检测方法。更多还原

【Abstract】 Electricity energy has become more and more important in daily life. Power system must work safe and rel iable to insure the normal of power supply system. So DC power system must work reliable, which is the core of power system, transformer substation.The question of DC system has become the main question about safe operation of trans format ion substation. The relay protection or the signal of electric monitoring system will abnormal operate when an exception occurs on dc system,and more it will cause serious result of the electric power system. This paper describes the main composition and design principle of DC power system, and the problem of joint earth is fully analyses, which is the important reason that causes the DC power system to refuse action or act abnormal. This paper analyses the operating characteristics of break and fuse, describes the main problem on Staged difference coordinations of DC system, and the reasonable proposals are given to choice the breakers and the fuses in DC system. At last, this paper compares the pro and con of all kinds of insulation monitoring technique through the analysis and research of several popular insulation monitoring techniques, and then decides to adopt the way of imbalanced electronic bridges and the inserting signal method.更多还原