桥式起重机变频调速毕业设计论文.doc

毕业设计（论文） 论文题目 ABSTRACT Bridge crane as a material handling system of a kind of typical equipment, is widely used in industrial production, significant role. Therefore to improve the operating efficiency of the bridge crane to ensure the safety and reliability of operation, reduce material handling costs is very necessary. The according to the characteristics of the crane operation, adopting the driving of disperse, combining with the technology of frequency conversion, completed the bridge crane fixed frequency speed control. The PLC as logic controller, and the design of the ladder diagram, the cam controller signal as the input signal of the PLC, the PLC output connected to an intermediate relay coil, through the contacts of the relay control of the digital converter input port and inverter connected two motor variable frequency speed regulation. In order to facilitate control and emergency treatment, the design of the starting, stop, reset the fault and emergency stop button. At the same time the motor nameplate parameters input to the inverter, Using inverter protection circuit protection. Through this design can control the motor starting, stop, running direction, shift speed and fault reset. Thus reducing the traditional relay - contact type control system of intermediate links, reducing the hardware and control line, greatly improving the stability and reliability of the system. Key words: bridge crane cam controller programmable controller variable frequency speed regulation  目录 摘要 I 目录 III 第一章 绪论 1 1.1 桥式起重机电气传动技术的国内外发展概况 1 1.2 传统桥式起重机控制系统存在的问题 2 1.3 本课题的研究意义及主要内容 2 1.4 本章小结 3 第二章 变频调速的原理 4 2.1 交流异步电动机变频调速原理 4 2.2 变频调速系统的控制方式 4 2.3 变频器的基本结构 5 2.4 本章小结 9 第三章 MM440与S7-200 9 3.1 MM440变频器 9 3.2 PLC系统组成与各部分的作用 10 3.3 变频器和PLC的关系 13 3.4 本章小结 13 第四章 桥式起重机大车变频调速系统设计 15 4.1 桥式起重机大车组成及特点 15 4.2 系统总体设计 16 4.3 变频器参数设计及PLC的I/O分配 18 4.4 变频器实现三段调速原理的解释 20 4.5 PLC程序设计 20 4.6 电器布置图和电气接线图 21 4.7 本章小结 24 第五章 总结与展望 25 致谢 26 参考文献 27 附录.................................