基于PLC的大型变压器冷却监控系统设计
基于PLC的大型变压器冷却监控系统设计[20200410135909]
摘要
在变电所中，大型变压器一般采用强迫油循环风冷却方式，这种冷却方式一般采用YF型强迫油循环冷却器冷却，冷却系统由四组散热器组成，沿油箱周围均对称分布，对变压器运行中产生的热量进行冷却。
冷却系统控制的传统方式为继电器控制。该控制模式线路复杂、接点接线多，存在可靠性差、维护和监控不方便的问题。本课采用PLC为核心的风冷控制系统，用软件设计代替了原来风冷系统的继电器控制方式，去掉了原来庞大、复杂的硬件电路，提高了系统的系统可靠性。利用个人计算机（PC）作为上位机，利用“组态王”软件作为程序开发平台，和以PLC为核心的下位机控制装置组成一个变压器冷却监控系统。
*查看完整论文请 +Q: 3 5 1 9 1 6 0 7 2
关键字:S7-200PLCPID组态王
目录
1. 绪论····································································1
1.1 课题背景和意义························································1
1.2 冷却控制装置研究现状··················································2
1.3 本毕业设计的主要工作··················································2
1.4 系统总体设计··························································2
2. 硬件设计································································4
2.1 CPU 222·······························································4
2.2 EM 235扩展模块························································4
2.2.1 EM 235技术参数····················································5
2.2.2 EM 235模块接线····················································4
2.2.3 EM 235模块设置····················································6
2.3 西门子MicroMaster420变频器···········································6
2.4 温度传感器····························································7
2.5 硬件电路设计··························································7
3. 软件设计·······························································10
3.1 下位机设计···························································10
3.1.1 PLC概述··························································10
3.1.2 PID控制算法······················································10
3.1.3 PLC程序段························································11
3.2 上位机设计···························································15
3.2.1 组态王概述·······················································15
3.2.2 定义I/O设备·····················································15
3.2.3 人机界面的设计···················································17
4. 程序调试的结果························································22
5. 总结与展望····························································23
5.1 总结·································································23
5.2 展望·································································23
参考文献··································································24
附录·······································································25
1.PLC程序································································25
2.组态王命令语言··························································30
致谢·······································································34
1. 绪论
1.1 课题背景和意义
在变电所和输电线路中，实现电能转换的最基础、最重要的设备就是变压器，在供电可靠性上有着非常重要的影响。在运行过程中，变压器会产生两种损耗，一种损耗是空载上的损耗，它和负荷的大小没有关系；另一种则是负载损耗，与负载电流的平方成正比。在运转的过程中，那些从变压器中产生的耗损将会转变成热能，然后发送出去，使得变压器里面的铁芯和绕组变热，也会让变压器的油温迅速增长。变压器的温度升高不仅会影响它的承载能力，同时也促进通过变压器绕组和铁芯使用绝缘材料的老化，从而影响其能够使用的寿命。
变压器运行过程中所带的负荷在任何时刻都在改变，这将会改变变压器上所产生的损耗，从而也改变变压器的油温；同时，无论是一年四季环境气温的变化，还是每天昼夜气温的变化，都会对变压器油温造成改变。所以，为了能够让变压器经济、安全、稳定的运作，就必须要无时无刻的检查变压器的油温，并且还要通过使用冷却控制装置来限制变压器的油温，使其维持在一个固定的范围内。但是，现在大部分大型电力变压器的冷却控制还在使用传统的继电式控制方式，这类控制的方式还存在着许多的坏处：控制回路的接线非常的复杂、可靠性又很差、故障率也比较高、维护工作量还非常大，使得冷却器运作非常不平衡，因而大大的缩短了冷却器组能够利用的时间，同时它还不可以节约能源；当变压器的负荷振动很大，而使得变压器的油温产生改变时，通常需要采用对温度硬触点进行控制，使得冷却器组经常启动和停止，导致冷却器组能够使用的寿命一再的下降,又使油流的带电现象加剧了；不能够保护好冷却器的风扇、油泵电动机。因为控制系统中存在的毛病，继电式的控制系统会让变压器带“病”运转，就会将会对变压器的可靠运行产生严重的影响，它已经不能够满足现在电网的发展需求了。本课题就是针对变压器存在的问题研制开发出了基于PLC的大型变压器的冷却监控系统。
摘要
在变电所中，大型变压器一般采用强迫油循环风冷却方式，这种冷却方式一般采用YF型强迫油循环冷却器冷却，冷却系统由四组散热器组成，沿油箱周围均对称分布，对变压器运行中产生的热量进行冷却。
冷却系统控制的传统方式为继电器控制。该控制模式线路复杂、接点接线多，存在可靠性差、维护和监控不方便的问题。本课采用PLC为核心的风冷控制系统，用软件设计代替了原来风冷系统的继电器控制方式，去掉了原来庞大、复杂的硬件电路，提高了系统的系统可靠性。利用个人计算机（PC）作为上位机，利用“组态王”软件作为程序开发平台，和以PLC为核心的下位机控制装置组成一个变压器冷却监控系统。
*查看完整论文请 +Q: 3 5 1 9 1 6 0 7 2
关键字:S7-200PLCPID组态王
目录
1. 绪论····································································1
1.1 课题背景和意义························································1
1.2 冷却控制装置研究现状··················································2
1.3 本毕业设计的主要工作··················································2
1.4 系统总体设计··························································2
2. 硬件设计································································4
2.1 CPU 222·······························································4
2.2 EM 235扩展模块························································4
2.2.1 EM 235技术参数····················································5
2.2.2 EM 235模块接线····················································4
2.2.3 EM 235模块设置····················································6
2.3 西门子MicroMaster420变频器···········································6
2.4 温度传感器····························································7
2.5 硬件电路设计··························································7
3. 软件设计·······························································10
3.1 下位机设计···························································10
3.1.1 PLC概述··························································10
3.1.2 PID控制算法······················································10
3.1.3 PLC程序段························································11
3.2 上位机设计···························································15
3.2.1 组态王概述·······················································15
3.2.2 定义I/O设备·····················································15
3.2.3 人机界面的设计···················································17
4. 程序调试的结果························································22
5. 总结与展望····························································23
5.1 总结·································································23
5.2 展望·································································23
参考文献··································································24
附录·······································································25
1.PLC程序································································25
2.组态王命令语言··························································30
致谢·······································································34
1. 绪论
1.1 课题背景和意义
在变电所和输电线路中，实现电能转换的最基础、最重要的设备就是变压器，在供电可靠性上有着非常重要的影响。在运行过程中，变压器会产生两种损耗，一种损耗是空载上的损耗，它和负荷的大小没有关系；另一种则是负载损耗，与负载电流的平方成正比。在运转的过程中，那些从变压器中产生的耗损将会转变成热能，然后发送出去，使得变压器里面的铁芯和绕组变热，也会让变压器的油温迅速增长。变压器的温度升高不仅会影响它的承载能力，同时也促进通过变压器绕组和铁芯使用绝缘材料的老化，从而影响其能够使用的寿命。
变压器运行过程中所带的负荷在任何时刻都在改变，这将会改变变压器上所产生的损耗，从而也改变变压器的油温；同时，无论是一年四季环境气温的变化，还是每天昼夜气温的变化，都会对变压器油温造成改变。所以，为了能够让变压器经济、安全、稳定的运作，就必须要无时无刻的检查变压器的油温，并且还要通过使用冷却控制装置来限制变压器的油温，使其维持在一个固定的范围内。但是，现在大部分大型电力变压器的冷却控制还在使用传统的继电式控制方式，这类控制的方式还存在着许多的坏处：控制回路的接线非常的复杂、可靠性又很差、故障率也比较高、维护工作量还非常大，使得冷却器运作非常不平衡，因而大大的缩短了冷却器组能够利用的时间，同时它还不可以节约能源；当变压器的负荷振动很大，而使得变压器的油温产生改变时，通常需要采用对温度硬触点进行控制，使得冷却器组经常启动和停止，导致冷却器组能够使用的寿命一再的下降,又使油流的带电现象加剧了；不能够保护好冷却器的风扇、油泵电动机。因为控制系统中存在的毛病，继电式的控制系统会让变压器带“病”运转，就会将会对变压器的可靠运行产生严重的影响，它已经不能够满足现在电网的发展需求了。本课题就是针对变压器存在的问题研制开发出了基于PLC的大型变压器的冷却监控系统。
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