1、 I 摘 要 变电站是电力系统的重要组成部分,它直接影响整个电力系统的安全与经济 运行,是联系发电厂和用户的中间环节,起着变换和分配电能的作用。 本次毕业设计以 35kV 变电站为设计对象, 设计的主要内容包括负荷计算、 变 压器的选择、电气主接线设计、短路计算、电气设备的选择、变压器及输电线路 继电保护设计。 首先,根据变电站的负荷资料对变电站进行负荷计算。根据负荷计算结果来 确定变压器的容量和台数, 选用 2 台型号为 SFSZ96300/35 的主变压器。 这两台 变压器同时运行,互为备用。而后根据电气主接线的设计原则,选择出最稳定可 靠的接线方式,即 110kV、 35kV 和 10k
2、V 侧都采用单母线分段接线。接下来确定 3 个短路点,通过等效化简及标幺值计算的方法,对各短路点分别进行短路电流 计算。根据计算结果进行电气设备的选择,包括断路器、隔离开关、母线、电流 和电压互感器等。为了保证变电站的安全运行,进行变压器和输电线路的继电保 护设计。 作为电能传输与控制的枢纽, 本次变电站设计改变了传统的设计和控制模式, 能更好地适应现代电力系统、现代化工业生产和社会生活的发展趋势。 关键词:变电站;电气主接线;短路计算;电气设备 II Abstract Power substation is an important component of the system, it h
3、as a direct impact on the entire electricity system for the security and economic operation of power plants and users to link the intermediate links, transformation and distribution of electric energy to play the role. This graduation project take the 35kV substation as the design object, the design
4、 consists of load calculation, the choice of transformers, main electrical connection design, short circuit calculation, the choice of electrical equipment, transformer and transmission line relay protection design. Firstly, according to the basis of known information of the substation load to make
5、load calculation. Under the result of load calculation to determine the capacity and the number of the transformer. Then selected two transformers and their models is SFSZ9-6300 /35. The two transformers to run, mutual backup. And then according the principles of the main electrical connection desig
6、n to select the most stable and reliable connection, that a single sub-bus connection at 35kV ,10kV and 10kV side. Determine three short-circuit points, Simplification and by the equivalent per unit value calculation ,then calculated short-circuit current of respective short point. According the calculation results to choose the electrical equipments, including circuit breakers, disconnect switches, bus bar,current and potential transformers. In order to ensure the safe operation of substation