【作者】 刘凯；

【导师】 关根志；

【作者基本信息】 武汉大学 ， 高电压与绝缘技术， 2004， 硕士

【摘要】 电力变压器广泛地应用于电力系统中。变压器绕组直流电阻的测量对于检验生产过程中变压器产品的工艺质量、发现现场中变压器的缺陷以及变压器故障后的检查、分析与判断等都具有十分重要的意义。IEC标准和国标对变压器绕组直流电阻的测量做出了相应的标准规定。 在进行变压器绕组直流电阻的测量时，变压器绕组可以等效为一个由电阻、电感组成的串联电路。由于电力变压器的绕组具有大电感、微电阻的特点，其固有时间常数较大，造成了传统的绕组直流电阻的测量方法需要很长时间才能得出结果，给现场测量带来了很多不便。这一现象对测量的快速性提出了要求。 论文结合实际情况，在分析、比较目前现存的各种测量方法的基础上，针对变压器绕组的特性，从基本的电路出发，推导出了一种在变压器绕组的过渡过程中测量其直流电阻的新方法，该方法具有快速、简单、准确的特点。在此基础上，经过大量电路实验和仿真调试，完成了基于这种新的快速测量方法的以单片机为核心的智能仪器的硬件和软件的设计。 本文共分五章：第一章简要介绍了本课题的意义、仪器仪表的发展和论文的主要内容以及工作重点；第二章在分析、比较现有的各种测量变压器绕组直流电阻的方法的基础上，从变压器绕组的特性和基本电路入手，经过分析，推导出了一种新的快速测量方法并对新的测量方法进行了一定的分析与验证；第三章详细阐明了基于新的测量方法的智能仪表的硬件部分的设计；第四章介绍了智能仪表的软件部分设计及实现；在此基础上，第五章中进行了样机的模拟实验，对实验进行了一定分析，总结了所作的工作和取得的主要成果，并指出了装置的不足和改进的方向。更多还原

【Abstract】 Transformers are widely used in the power system. The measurement of the DC resistance of transformers’ windings has great importance in checking their quality as their being manufactured, finding their defects on the operating spot, and analyzing and deciding faults after they failed. The IEC standards and national standards both have corresponding items about the measurement of DC resistance of transformers’ windings.During the measuring of the DC resistance of a transformer’s winding, the winding is equivalent to a resistance-inductance series circuit. Because power transformers often have big inductance but small resistance, they usually have big characteristic time. This result in the fact that the traditional measuring methods cost too much time before getting the result, and thus bring about much inconvenience, so quickly measuring method is needed to be found..In this paper, based on the analyzing and comparing of existing measuring methods, according to the inherent characteristics of transformers’ windings, from the basic circuit, a new quickly measuring method that calculates the DC resistance of the transformers’ windings during the transient process is deduced. The new method is quick, simple and accurate. And then, the design of hardware and software of the MCU centered intelligent instrument solution is prescribed in this paper.The paper is divided into 5 chapters. In cheaper 1, the purpose of measurement of DC resistance of transformers’ windings and the work done in this paper are briefly described. The deduction of the new quickly measuring method is described in chapter 2. In chapter 3, the hardware design of the intelligent instrument is described. And the software design of the intelligent instrument is described in cheaper 4. In chapter 5, the work done and the deficiency of the instrument and further work to be done are discussed.更多还原