1、 I 摘要摘要 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。电气主接 线是发电厂变电所的主要环节，电气主接线的拟定直接关系着全所电气设备的选 择、配电装置的布置、继电保护和自动装置的确定，是变电站电气部分投资大小 的决定性因素。 本次设计建设一座采用屋内 GIS 配电装置的 TQ 化肥厂 110kV 降压变电所。 首先，根据主接线的经济可靠、运行灵活的要求选择各个电压等级的接线方式， 在技术方面和经济方面进行比较，选取灵活的最优接线方式。 其次进行短路电流计算，根据各短路点计算出各点短路稳态电流和短路冲击 电
2、流，从三相短路计算中得到当短路发生在各电压等级的工作母线时，其短路稳 态电流和冲击电流的值。 最后，根据各电压等级的额定电压和最大持续工作电流进行设备选择，然后 进行校验。 同时在设计过程中还要进行主变继电保护的整定计算和防雷保护的设计，以 保证本变电所能可靠安全的运行。 关键词关键词：降压变电所 变压器 电气主接线 短路电流 设备选择 防雷 继电保护 郑州大学电气工程学院毕业设计（论文） II AbstractAbstract Substation is an important part of the power system, which directly affects the ent
3、ire power systems security and economic operation. Its the middle part to contact power plants and the user, which plays the role of transformation and distribution of electric energy. Electrical power main connection is the major component of plant substation. The development of main power line is
4、directly related to the choice of all the electrical equipment, power distribution equipment layout, relay protection and automatic device identification, which is part of the size of investment of the electrical substation decisive factor. This design is a power distribution with the houses TQ GIS
5、110kV step-down substation for fertilizer plant. First, according to the economic and reliable operation and flexible requirements of the main power line it will select various voltage levels of wiring, and after technical and economic aspects in the comparison, the optimal flexible wiring should be
6、 selected. Second, the short-circuit current calculates. According to the points it calculates short circuit current and steady-state impact of short-circuit current , and its steady-state current and the impact of short-circuit current value is obtained from the three-phase short-circuit calculation when short-circuit occurs in the working bus of every voltage level. Finally, according to the voltage level of the rated voltage and maximum continuous operating current, equipment will be s
