110kv变电站的---初步设计 110kv变电站的电气主接线图形---大学生毕业设计论文.doc

110kV变电站的初步设计 摘 要 根据对原始资料背景和设计要求的分析，110kV变电站初步设计的主要内容包括：先试选电气主接线方案，然后进行技术性和经济性的比较，最终选择最合理的主接线形式；通过经济截面电流法，先选择变电所进线导线，为后续三相短路电流计算做铺垫；根据三相短路电流计算结果，选择符合使用要求的各种电气设备；最终是对变压器、线路进行保护。 通过综合分析，110kV侧入线是双电源供电，35kV和10kV母线选择的都是单母线接线。导线选择后，采用标幺值法计算等效电抗，通过查电源运算曲线的图表，找出短路瞬间、4s后的短路电流标幺值，而后将其转换成有名值，通过公式计算出冲击电流。至于电气设备的选择则是通过最大负荷电流和开断电流进行选择，根据4s后电流有名值和短路冲击电流有名值进行热稳定性和动稳定性校验；至于保护方面，主要是变压器的保护，通过延时时间不同，来让不同断路器动作，进而起到保护作用。 关键词：电气主接线，三相短路电流，变压器，线路保护，标幺值 PRELIMINARY DESIGN OF 110 kV SUBSTATION ABSTRACT According to the analysis of raw data background and design requirements, the main content of the preliminary design of the 110 kV substation including: Try to choose the main electrical wiring scheme, then carries on the technical and economical comparison, and finally choose the most appropriate form of the main wiring. Through the economical section current method, choose the substation into line conductor, which will pave for the subsequent three-phase short-circuit current calculation. According to the results of the three-phase short-circuit current calculation to choose all kinds of electrical equipment, which conform to the requirements. Transformer and line are ultimately to be protected. Through the comprehensive analyse, the side into line of 110 kV is double power supply, while 35 kV and 10 kV busbar selection are single busbar wiring. Use standard per unit method to calculate the equivalent reactance after selecting wire, and to find out the per units short-circuit current value of short circuit instantaneous and after 4s’ through checking the power operation curve chart, and then convert them into actual value, calculate the shock current based on the formula. As for the selection of electrical equipment, which is through the choice of maximum load current and open circuit current, carries on the thermal stability and dynamic stability check according to the after 4s’ current actual value and short circuit impact current actual value. The protection of transformer is main