大连海事大学
毕业论文
二O一一年六月
基于PLC船舶电站自动调频调载装置
设计
专业班级：船机修造2班 姓 名： ******** 指导教师： ************
轮机工程学院
摘 要
船舶电站的可靠运行对船舶安全、经济地运营起着重要的作用，而自动调频调载是船舶自动化电站的主要功能之一?1?。由于船舶电站的容量是有限的，某些大电动机的容量甚至可以与单机容量相比拟；而且船舶工况也较为复杂，如航行工况、进出港工况、停泊工况、装卸货工况等，这就导致运行在船舶电站上的负载总是处于动态的变化当中，因此，电网频率和各机组的负载分配情况也会随着工况的变化而相应地波动。为保障船舶用电设备的正常工作并最大限度发挥机组容量，必须采取相应的措施以保证电网频率的稳定和各机组负载的合理分配，本文采用PLC，设计出性能优良、工作可靠、反应迅速的船舶电站自动调频调载装置。
本文设计的船舶电站自动调频调载装置由一个主站和三个子站组成。主站是以Windows XP作为操作系统的工业PC控制机，对各个子站PLC进行编程和状态检测。每个子站由一台S7-300 PLC构成，独立控制一台发电机组，子站S7-300 PLC通过输入模块进行各种信号的采集，由CPU模块对各数据进行分析和处理，然后通过输出模块发出各种控制信号。
本文利用SIMATIC STEP7工业软件来进行系统的硬件组态和控制程序的编写，采用模块化的编程思想主要设计了自动起动模块、自动准同步并车模块、自动调频调载模块、自动解列与停机模块。
关键词：船舶电站；调频调载；PLC
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Abstract
The reliable working of ship power station has a very important effect on the safely and economically operating for ship, and frequency and load automatic control is one of the main functions for automatic ship power station. Due to the limited capacity for ship power station, some large motor’s capacity even can compare with the single generator’s capacity; Also the ship has a lot of working conditions, such as navigation condition、entry and exit condition、anchor condition、cargo condition and so on, these lead its load is always during dynamic variation; therefore, the power line’s frequency and each generator’s load distribution waves at the same time. To make sure the ship electro-equipment work normally and make full use of generators’ capacity, it is necessary to make adjustment accordingly to guarantee a steady frequency and reasonable load distribution. The PLC is used in this text, designing frequency and load automatic control for ship power station with excellent function, reliable operation, rapid response.
The ship power station frequency and load automatic control is composed of one operating station computer and three slave computers in this text. Master computer is an industrial PC with Windows XP as the operating system, we use it to program for the slave computer and detect its state. Every slave computer, consisting of Siemens S7- 300 PLC, controls a generator independently. Slave computers collects all kinds of symbols through input modules, the CPU module analysis and process all kinds of data and then have all kinds of control symbols through output modules.
The hardware configuration and control program for the system is designed by using SIMATIC Step7 industrial software in this text, mainly designing automatic start module, automatic quasi-synchronous parallel operation module, automatic frequency and load regulation module, automatic parallel off and stop module.
Keywords: Ship Power Station，Frequency and Load Modulate，PLC
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