电力变压器绕组变形在线检测系统的研制
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摘要
作为电力系统中的一个重要组件，变压器的安全运行对于保证电网的可靠性意义重大。近年来，由于变压器绕组变形直接或间接导致的变压器损坏事故居高不下。为了能及时发现变压器的事故隐患、避免突发事故、提高变压器运行的安全可靠性，开展变压器绕组变形的检测与诊断方法的研究具有十分重要的意义。
由变压器的理论分析可知：变压器的短路电抗值是由绕组的几何尺寸及相互位置所决定的。对于一台变压器而言，当绕组变形，几何尺寸及相互位置发生变化时，其短路电抗值也会变化，因而，如果运行中的变压器受到了短路电流的冲击，为检查其绕组是否变形，就可将短路前后的短路电抗值加以比较来判断，根据其变化的程度，作为判断变压器绕组变形程度的重要依据。例如，IEC和我国国家标准规定，对于同心式绕组，如果短路电抗变化量超过2％，即认为绕组有明显的变形。
理论分析表明，对于运行中的三相变压器，利用每相的电压互感器和电流互感器输出值，可以计算出变压器每相的短路电抗，并据此对电力变压器的绕组变形程度进行在线检测。
本文利用51系列单片机研制了变压器绕组变形在线检测系统，该系统可以实现数据采集、测量结果显示、与上位计算机通讯等功能。文中详细介绍了该系统的硬件设计方法，并对各主要功能部分进行了详细分析，包括：LCD显示器及键盘接口电路，A／D转换器件的选取及接口电路设计，电路板内部及其在机内整体安装上的硬件抗骚扰措施等。
测量系统的软件部分包括单片机系统控制软件和上位机软件。其中采用C51语言编制的单片机控制系统程序用来实现测量控制、数据采集和处理、显示、通信和人机对话等功能；上位机程序利用图形编程语言LabVIEW编制，它可实现与单片机系统的通信、数据处理、显示和数据库等功能，文中详细介绍了各个模块的设计方法。
利用该检测系统在实验室模型变压器上进行了模拟实验，测量结果表明此系统具有较高的精度和稳定性，达到了设计要求。
Transformer plays a key role in power system. Its safe operation guarantees the reliability of the power grid. In recent years, the ratio of the transformer faults caused by the winding deformation directly or indirectly remains very high. Therefore it is important to find out hidden trouble of transformer in time so as to avoid outburst accident and improve safety and reliability of transformer operation. The study on methods of detecting the transformer winding deformation is of great significance.
It is shown from the theoretical analysis of transformer that the short-circuit reactance of a transformer is decided by the size and the relative location of its windings. For a certain transformer, when the windings deformed and the size and the relative location varied, the value of the short-circuit reactance varied correspondingly. The extent of the variety can be used as the basic of the extent of the winding deformation. For example, by the rules of IEC and Chinese national standard, when the variety of the short-circuit reactance of a homocentric winding exceeds 2%, a certain extent of deformation can be affirmed.
By measuring the voltage signal of Potential Transformer (PT) and the current signal of the Current Transformer (CT) from the primary and secondary winding of the transformer in operation, the short-circuit reactance of each phase can be calculated. Therefore the on-line monitoring of winding deformation of transformer can be realized.
Based on the theory above, we developed a set of on-line detecting system on power transformer winding deformation using 51 series micro controller unit (MCU), which can perform data acquisition, displaying the result of measurement and communication with the IBM-PC. The hardware design methods of this system was introduced and much attention was paid to the main function part, including the LCD module and keypad interface circuit, the selection of AD converters and the interface circuit and the methods used to avoid the EMI on the PCB and in the shielding box.
The software of the on-line detecting system consists of two important parts, one is the MCU controlling software, and the other is the IBM-PC software. The MCU controlling software is to achieve the whole measurement control, data pick-up and processing, display and communication with the IBM-PC, etc. which is compiled with the C51 language. The IBM-PC software was complied with the graphical programming language LabVIEW, and can perform communication with the MCU, digital signal processing, displaying and the database. The design method of each part of the software was presented.
_____________________________________________Abstract_____________________________________________
Simulation experiment was performed on the transformer model using this system in the Lab. The result shows that this system is of high accuracy and reliability, which can meet the theoretical design demand.
由变压器的理论分析可知：变压器的短路电抗值是由绕组的几何尺寸及相互位置所决定的。对于一台变压器而言，当绕组变形，几何尺寸及相互位置发生变化时，其短路电抗值也会变化，因而，如果运行中的变压器受到了短路电流的冲击，为检查其绕组是否变形，就可将短路前后的短路电抗值加以比较来判断，根据其变化的程度，作为判断变压器绕组变形程度的重要依据。例如，IEC和我国国家标准规定，对于同心式绕组，如果短路电抗变化量超过2％，即认为绕组有明显的变形。
理论分析表明，对于运行中的三相变压器，利用每相的电压互感器和电流互感器输出值，可以计算出变压器每相的短路电抗，并据此对电力变压器的绕组变形程度进行在线检测。
本文利用51系列单片机研制了变压器绕组变形在线检测系统，该系统可以实现数据采集、测量结果显示、与上位计算机通讯等功能。文中详细介绍了该系统的硬件设计方法，并对各主要功能部分进行了详细分析，包括：LCD显示器及键盘接口电路，A／D转换器件的选取及接口电路设计，电路板内部及其在机内整体安装上的硬件抗骚扰措施等。
测量系统的软件部分包括单片机系统控制软件和上位机软件。其中采用C51语言编制的单片机控制系统程序用来实现测量控制、数据采集和处理、显示、通信和人机对话等功能；上位机程序利用图形编程语言LabVIEW编制，它可实现与单片机系统的通信、数据处理、显示和数据库等功能，文中详细介绍了各个模块的设计方法。
利用该检测系统在实验室模型变压器上进行了模拟实验，测量结果表明此系统具有较高的精度和稳定性，达到了设计要求。
Transformer plays a key role in power system. Its safe operation guarantees the reliability of the power grid. In recent years, the ratio of the transformer faults caused by the winding deformation directly or indirectly remains very high. Therefore it is important to find out hidden trouble of transformer in time so as to avoid outburst accident and improve safety and reliability of transformer operation. The study on methods of detecting the transformer winding deformation is of great significance.
It is shown from the theoretical analysis of transformer that the short-circuit reactance of a transformer is decided by the size and the relative location of its windings. For a certain transformer, when the windings deformed and the size and the relative location varied, the value of the short-circuit reactance varied correspondingly. The extent of the variety can be used as the basic of the extent of the winding deformation. For example, by the rules of IEC and Chinese national standard, when the variety of the short-circuit reactance of a homocentric winding exceeds 2%, a certain extent of deformation can be affirmed.
By measuring the voltage signal of Potential Transformer (PT) and the current signal of the Current Transformer (CT) from the primary and secondary winding of the transformer in operation, the short-circuit reactance of each phase can be calculated. Therefore the on-line monitoring of winding deformation of transformer can be realized.
Based on the theory above, we developed a set of on-line detecting system on power transformer winding deformation using 51 series micro controller unit (MCU), which can perform data acquisition, displaying the result of measurement and communication with the IBM-PC. The hardware design methods of this system was introduced and much attention was paid to the main function part, including the LCD module and keypad interface circuit, the selection of AD converters and the interface circuit and the methods used to avoid the EMI on the PCB and in the shielding box.
The software of the on-line detecting system consists of two important parts, one is the MCU controlling software, and the other is the IBM-PC software. The MCU controlling software is to achieve the whole measurement control, data pick-up and processing, display and communication with the IBM-PC, etc. which is compiled with the C51 language. The IBM-PC software was complied with the graphical programming language LabVIEW, and can perform communication with the MCU, digital signal processing, displaying and the database. The design method of each part of the software was presented.
_____________________________________________Abstract_____________________________________________
Simulation experiment was performed on the transformer model using this system in the Lab. The result shows that this system is of high accuracy and reliability, which can meet the theoretical design demand.
引文
[1] 徐大可．监测变压器绕组变形的短路电抗在线测量技术．博士论文，2000．5
[2] 关根志，贺景亮．电气设备的绝缘在线监测与状态维修．中国电力，2000，33(3)：46
[3] 严璋．电气绝缘在线检测技术．中国电力出版社，1995．11
[4] 陈化刚，张开贤等．电力设备异常运行及事故处理．中国水利水电出版社，1999
[5] 凌愍，王圣．110kV级变压器事故统计及短路故障分析．变压器，1995，32(12)：33
[6] 王钰，李彦明，张成良．变压器绕组变形检测的LVI法和FRA法的比较研究．高电压技术，1997，23(1)：13
[7] 王钰，徐大可，李彦明．检测变压器绕组变形的低压脉冲法测试系统的研究．高电压技术，1998，24(3)：24
[8] 王钰，李彦明，秦少臻等．变压器绕组变形检测中的故障判定．高电压技术，1997，23(3)：23
[9] 何文林．变压器绕组变形测试方法探讨．浙江电力，1996，6：28
[10] 辜超．TWD—Ⅱ型变压器绕组变形测试仪的研制及应用．山东电力技术，2002，5：8
[11] 曾刚远．测量短路电抗是判断变压器绕组变形的有效方法．变压器，1998，35(8)：13
[12] 陈志勇，闫春雨，王伟等．频率响应法对变压器绕组变形的分析．河北电力技术，2002，4：45
[13] 刘传彝．电力变压器设计计算方法与实践．辽宁科学技术出版社
[14] 徐大可，李彦明．变压器绕组变形在线监测的应用研究．高电压技术，2001，27(4)：21
[15] 徐大可，汲胜昌，李彦明．变压器绕组变形在线监测的理论研究．高电压技术，2000，26(3)：16
[16] Emesto Arri, Alessandro Carta, Francesco Mocci etc. Diagnosis of the state of power transformer windings by on-line measurement of stray reactance. IEEE Trans. Instrum. Meas. 1993, 42(2): 372
[17] 胡汉才．单片机原理及系统设计．清华大学出版社，2002．1
[18] Micro controller Handbook. Intel Corp, 1986
[19] 李华等．MCS—51系列单片机实用接口技术．北京航空航天大学出版社，
1993．8
[20] 刘乐善等．微型计算机接口技术及应用．华中科技大学出版社，2000．4
[21] 王幸之，王雷，翟成等．单片机应用系统抗干扰技术．北京航空航天大学出版社，2000．2
[22] 范锡普．发电厂电气部分．中国电力出版社，1995．11
[23] 杨乐平，李海涛，肖相生．LabVIEW程序设计与应用．电子工业出版社，2001．7
[24] Robert H．Bishop著，乔瑞萍等译．LabVIEW 6i实用教程．电子工业出版社，2003．1
[25] LabVIEW user manual. National Instruments Corporation, 1998
[26] 蒋豪贤．电机学．华南理工大学出版社，1997．9
[27] 梁晋文，陈林才，何贡．误差理论与数据处理．中国计量出版社，2001．8
[28] 马忠梅等．单片机的C语言应用程序设计．北京航空航天大学出版社，1999．1
[29] 陈生潭等．信号与系统．西安电子科技大学出版社，1990．8
[30] 王世一．数字信号处理．北京理工大学出版社，1997．11
[31] 潘文，钱俞寿，周鹗．基于加窗插值FFT的电力谐波测量理论(Ⅰ)窗函数研究．电工技术学报，1994，1：50
[32] 蒋焕文，孙续．电子测量(第二版)．中国计量出版社，1988．5
[2] 关根志，贺景亮．电气设备的绝缘在线监测与状态维修．中国电力，2000，33(3)：46
[3] 严璋．电气绝缘在线检测技术．中国电力出版社，1995．11
[4] 陈化刚，张开贤等．电力设备异常运行及事故处理．中国水利水电出版社，1999
[5] 凌愍，王圣．110kV级变压器事故统计及短路故障分析．变压器，1995，32(12)：33
[6] 王钰，李彦明，张成良．变压器绕组变形检测的LVI法和FRA法的比较研究．高电压技术，1997，23(1)：13
[7] 王钰，徐大可，李彦明．检测变压器绕组变形的低压脉冲法测试系统的研究．高电压技术，1998，24(3)：24
[8] 王钰，李彦明，秦少臻等．变压器绕组变形检测中的故障判定．高电压技术，1997，23(3)：23
[9] 何文林．变压器绕组变形测试方法探讨．浙江电力，1996，6：28
[10] 辜超．TWD—Ⅱ型变压器绕组变形测试仪的研制及应用．山东电力技术，2002，5：8
[11] 曾刚远．测量短路电抗是判断变压器绕组变形的有效方法．变压器，1998，35(8)：13
[12] 陈志勇，闫春雨，王伟等．频率响应法对变压器绕组变形的分析．河北电力技术，2002，4：45
[13] 刘传彝．电力变压器设计计算方法与实践．辽宁科学技术出版社
[14] 徐大可，李彦明．变压器绕组变形在线监测的应用研究．高电压技术，2001，27(4)：21
[15] 徐大可，汲胜昌，李彦明．变压器绕组变形在线监测的理论研究．高电压技术，2000，26(3)：16
[16] Emesto Arri, Alessandro Carta, Francesco Mocci etc. Diagnosis of the state of power transformer windings by on-line measurement of stray reactance. IEEE Trans. Instrum. Meas. 1993, 42(2): 372
[17] 胡汉才．单片机原理及系统设计．清华大学出版社，2002．1
[18] Micro controller Handbook. Intel Corp, 1986
[19] 李华等．MCS—51系列单片机实用接口技术．北京航空航天大学出版社，
1993．8
[20] 刘乐善等．微型计算机接口技术及应用．华中科技大学出版社，2000．4
[21] 王幸之，王雷，翟成等．单片机应用系统抗干扰技术．北京航空航天大学出版社，2000．2
[22] 范锡普．发电厂电气部分．中国电力出版社，1995．11
[23] 杨乐平，李海涛，肖相生．LabVIEW程序设计与应用．电子工业出版社，2001．7
[24] Robert H．Bishop著，乔瑞萍等译．LabVIEW 6i实用教程．电子工业出版社，2003．1
[25] LabVIEW user manual. National Instruments Corporation, 1998
[26] 蒋豪贤．电机学．华南理工大学出版社，1997．9
[27] 梁晋文，陈林才，何贡．误差理论与数据处理．中国计量出版社，2001．8
[28] 马忠梅等．单片机的C语言应用程序设计．北京航空航天大学出版社，1999．1
[29] 陈生潭等．信号与系统．西安电子科技大学出版社，1990．8
[30] 王世一．数字信号处理．北京理工大学出版社，1997．11
[31] 潘文，钱俞寿，周鹗．基于加窗插值FFT的电力谐波测量理论(Ⅰ)窗函数研究．电工技术学报，1994，1：50
[32] 蒋焕文，孙续．电子测量(第二版)．中国计量出版社，1988．5