降压变电站电气毕业设计.doc

摘 要 变电站作为电力系统中的重要组成部分，直接影响整个电力系统的安全与经济运行。本论文中待设计的变电站是一座降压变电站，在系统中起着汇聚和分配电能的作用，担负着向该地区工厂、农村供电的重要任务。 本文首先根据主接线的经济可靠、运行灵活的要求，每侧各选择几种待选主接线方案进行了技术比较，淘汰较差的方案，确定了变电站电气主接线方案。通过对原始资料的分析及根据变电站的总负荷关键词 电气主接线设计? 短路电流计算 ?电气设备选择? ABSTRACT Substation as an important part of power system, directly affects the whole power system safety and economical operation. This thesis is to design a step-down transformer substation, plays in the system and the distribution of electricity together, shoulder to rural power plant, the area of the important task. The design according to the first two wiring economical and reliable, flexible operation, each measure each choose two to choose the wiring schemes are compared, the elimination of the poor, determines the substation auto-switch scheme. Then based on the original data analysis and the total load determined according to the substation main transformer windings of the Numbers and capacity, and winding, connection pressure cooling mode, finally determined as the main transformer. The third is to short-circuit current calculation, from the three-phase short-circuit calculation of short-circuit occurred in each when the bus voltage level, its short-circuit current and impulse current steady-state value. According to the calculation results and the voltage level of rated voltage and maximum continuous working current main electrical equipment selection and calibration (including breaker, isolating switch, current transformer, voltage transformer, etc.). The fourth according to the principle of transformer protection substation configuration and the data of the main transformer station complete protection configuration and setting . Finally, according to the front of the main wiring schemes, the choice of transformer, electric equipment, the selection of main transformer protection in the design drawing a hook, protect the electric circuit principle diagram . Keywords: the main electrical wiring design；short-circuit current calculation； electri