石家庄某500kV变电站主变智能冷却控制系统的研究与设计

发布时间：2018-03-25 05:37

本文选题：PLC　切入点：智能冷却系统　出处：《华北电力大学》2017年硕士论文

【摘要】：随着我国电力系统电压等级的升高,进而超特高压电网的发展,电力变压器对电网的安全可靠性也变得至关重要,石家庄某500kV变电站是华北电网的重要一环,承载着河北、北京等地的重要输变电任务,但是其主变冷却控制系统仍采用继电器逻辑控制方式,其具有控制回路复杂、故障率高、检修困难、可靠性低、控制误差大等的诸多缺点,严重威胁着电网供电可靠性。随着无人值守变电站管理模式的逐步推广,针对继电器控制方式的诸多缺陷,结合相关的规程规定和现场运维人员的建议,本文提出以PLC为中心控制器,变压器顶层油温为被控量,无触点的交流固态继电器代替交流接触器作为执行元件,变压器冷却装置为被控对象的基于PLC的智能冷却控制系统,该系统以双电源自动转换开关保证两路电源的供电可靠性,以电动机保护器对风机和油泵冷却器的电动机进行短路、过载、过压等保护,另外辅以相应的开关旋钮器件、油面温度计以及现场就地冷却控制柜组成。除了以上所述硬件部分的设计,本课题对冷却控制系统的软件部分也做了大量的研究,结合PLC下位机软件编程设计,提出有差值裕度冷却器投切控制、按运行时间轮询投切冷却器控制、工作冷却器故障自动控制、冷却器全停控制等综合智能冷却系统控制策略。另外,结合变电站现场高电磁干扰的环境影响,提出PLC下位机与上位工控机使用光纤进行远距离通讯,利用上位机LABVIEW软件编程实现冷却控制系统的远程通讯监控。新型系统可以极大的克服原先继电式冷却控制系统的诸多缺点,其具有易于扩展、功能完善、运行可靠、便于维护等优点,实现了冷却系统的智能化控制,是传统变压器风冷控制系统的理想替代产品。
[Abstract]:With the rise of voltage grade of power system in China and the development of UHV power grid, power transformer is also becoming very important to the safety and reliability of power network. Shijiazhuang 500kV substation is an important link of North China Power Grid, carrying Hebei. Important power transmission and transformation tasks in Beijing and other places, but its main transformer cooling control system still adopts relay logic control mode. It has many shortcomings such as complex control circuit, high failure rate, difficult maintenance, low reliability, large control error, etc. The power supply reliability of power network is seriously threatened. With the gradual promotion of unattended substation management mode, in view of the many defects of relay control mode, combined with the relevant regulations and suggestions of field operation and maintenance personnel, This paper presents an intelligent cooling control system based on PLC, which takes PLC as the central controller, the top oil temperature of the transformer as the controlled quantity, the contactless AC solid state relay as the executive element instead of the AC contactor, and the transformer cooling device as the controlled object. The system guarantees the reliability of the power supply of the two power sources by the double power automatic switching switch. The motor protector is used to protect the motor of the fan and the oil pump cooler from short circuit, overload, overvoltage, and the corresponding switch knob device. In addition to the design of the hardware mentioned above, the software part of the cooling control system is also studied in this paper, and combined with the software programming design of the PLC lower computer, the oil surface thermometer and the in-situ cooling control cabinet are composed of the oil surface thermometer and the in-situ cooling control cabinet. A comprehensive intelligent cooling system control strategy, such as switching control with differential margin cooler, polling switch cooler control according to running time, automatic control of working cooler fault, complete shutdown control of cooler, etc., is put forward. Combined with the environmental impact of high electromagnetic interference in substation, the paper puts forward that the PLC lower computer and the upper industrial control computer use optical fiber for long-distance communication. The remote communication and monitoring of cooling control system is realized by using LABVIEW software of host computer. The new system can greatly overcome many shortcomings of the former relay cooling control system, which is easy to expand, perfect in function and reliable in operation. The intelligent control of cooling system is realized, and it is an ideal substitute for traditional air cooling control system of transformer.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM63

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