更新时间:12-03 (莉雅)提供原创文章
摘要:输电线路是电力系统的大动脉,担负着将电能从发电厂输送到各地用电中心的重要任务,是连接各个变电站、各用电用户的纽带。输电线路的安全运行,直接影响到了电网的稳定和用户的可靠供电。因此输电线路的安全运行在电网中占据着举足轻重的地位。
在保证输电线路安全的措施中,自动重合闸是一个非常重要的装置,因为在电力系统故障中,大多数是输电线路(特别是架空线路)的故障。在这些故障中有“瞬时性故障”和“永久性故障”,因此在线路被断开以后再进行一次合闸就有可能大大地提高供电的可靠性和减少停电损失。为此在电力系统中广泛采用了当断路器跳闸以后能够自动地将断路器重新合闸的自动重合闸装置。
由于输电线路长,地处旷野,因此极易遭受雷击,电力系统的雷害事故中以输电线路的事故占大多数。雷击是造成线路跳闸的主要原因。同时雷击线路时形成的雷电过电压波会沿线路侵入到变电站,危机变电站内电气设备的安全。加强输电线路的防雷是减少电力系统雷害事故的关键,因此对输电线路的防雷保护应给与充分的重视。
本设计的主要内容包括:首先通过输送容量、线路长度、功率因数以及利用电流经济密度来确定导线型号,设计出输电线路的主接线图,其次再对输电线路的防雷保护和线路保护进行选择和设计,最后再对输电线路的自动重合闸进行选择和设计。
关键词:35KV输电线路;线路主接线;防雷保护;线路保护;自动重合闸。
Abstract:Transmission lines is the artery of power system, assuming the energy from the plant to distribute it an important task of electricity center, is to connect each substation, the electricity users of the link. The safe operation of the transmission line, directly affecting the stability of the power grid and the user's reliable power supply. So the transmission lines in the safe operation of the power of holds an important position.
In order to ensure the safety of the transmission line measures, automatic reclosing is a very important devices, because in electric power system fault, most is the transmission lines (especially the overhead lines) fault. In these fault in the "the almost fault" and "permanent fault", so in line be disconnected again after a close brake may greatly improve the reliability of the power supply and reduce the loss of power. Therefore in the power system is widely used in a circuit breaker tripped later can automatically will circuit breaker feeder to automatic reclosing device.
Because the transmission lines long, is located in the wilderness, so easily shock, electric power system against accident to ray transmission lines accident majority. Lightning is caused line the main reason for the trip. At the same time lightning lines formed when lightning overvoltage waves along the road will invade substations, the crisis in the transformer substation of electrical equipment safety. Strengthen transmission line lightning protection is to reduce the harm of electric power system ray accident key, so the transmission line lightning protection should be given sufficient attention.
The design of the main content includes: first through the transmission capacity, line length and power factor and the use of current economic density to determine the wire types, and the design of the Lord the wiring diagram transmission lines, and then the lightning protection for transmission lines and line protection to choose and design, and finally to the transmission lines to the automatic reclosing selection and design.
Key words:35 KV transmission lines; The wiring circuit; Lightning protection; Line protection; Automatic reclosing.