摘要：本设计的题目是“某轧钢车间变电所的设计及基于PLC的轧钢流程模拟”。本设计的内容包括：车间的负荷计算及无功功率的补偿；车间变电所的变压器选择；变电所电气主接线的设计和绘制；短路电流计算；电气设备的选择（如母线、高压断路器、隔离开关、电流互感器、电压互感器、补偿电容器）；低压母线的选择；变电所进出线的选择；车间的变压器的继电保护。

     由于轧钢车间在该厂中属于二级负荷，车间采用四班三运转的连续工作制度，对电源的供电可靠性要求较高，宜采用两台变压器以暗备用的方式工作，以便当一台发生故障时，另一台能短时的承担所有负荷，不至于断电，这样就提高了供电可靠性。根据电气主线设计应满足可靠性、灵活性、经济性的要求，本变电所电气主接线的高压侧采用单母线接线，低压侧采用单母线分段的电气主接线形式；对低压侧负荷的统计计算采用需要系数法；为减少无功损耗，提高电能的利用率， 本设计进行了无功功率补偿设计；短路电流的计算包括短路点的选择及其具体数值计算；而电气设备选择采用了按额定电流选择，按短路电流计算的结果进行校验的方法。

　　　在这个设计中为了更直观的了解轧钢的工艺流程，在设计中加入了可编程控制器的知识。用PLC编程能通过实验直观的模拟轧钢生产的流水线作业。

　　　本次课程设计涉及面较广，查阅了大量资料，由于很多方面的知识都是通过查阅资料所得，边学边做，因此，错误与疏漏之处再所难免，望各位老师批评指正。

关键词: 电气主接线；设备选择；变压器继电保护；PLC

Abstract：This design topic is a rolling steel workshop substation electrical design based on PLC and the rolling process simulation. In this design content includes: workshop of load calculation and reactive power compensation; The workshop of the transformer substation choice; The main electrical substation wiring design and drawing; Short-circuit current calculation; Electrical equipment choice (such as bus bar, high voltage circuit breaker, isolating switch, current transformer, voltage transformer, compensation capacitor, lightning arrester); Low voltage bus choice; The choice of the outlet substation; workshop of transformer protection. 

　　Because in this plant, steel rolling workshop belonged to level 2 load, workshop adopted four class three operation of the continuous work system, the power supply reliability the demand is higher, appropriate USES two transformer with dark spare way, so that when a is at fault, the other a can of short for all load, and not without electricity, and, thus improving the power supply reliability. According to the main line design should meet the electrical reliability and flexibility, economy requirement, the main electrical wiring substation high pressure side by a single bus wiring, low voltage side by a single bus segmentation of the main electrical wiring form; Low voltage side of the load of statistical calculation need coefficient method; To reduce the reactive power loss and increase the energy utilization ratio, this design are reactive power compensation design; The calculation of short-circuit current including the choice of short-circuit point and its concrete numerical calculation; And electrical equipment selection using the rated current choice, according to the results of the short-circuit current calculation method of check; The lightning rod brings to the substation thunder protection. In this design more intuitive understanding of the rolling process, in the design with the programmable controller of knowledge. Through the experiment with PLC programming can intuitive simulation of steel rolling production assembly line homework. 

　　This course to a wide range of design, access to a large number of data, because many aspects of the knowledge through data access income, to refer to the correctness of the material and no one research, therefore, error and inaccuracies brewing, I hope each teacher criticism to correct. 

Key words:  the main electrical wiring；Equipment choice；Transformers relay protection；PLC