大型电力变压器绕组直流电阻“三点法”测试研究

Testing by "Three Points Method" of the Direct Current Resistance in Power Transformer Coil

提出了“三点法”动态测量大型电力变压器绕组直流电阻的原理和方法，即利用电阻、电感在直流电源作用下的充电过渡过程，用计算机技术调节充电过程的时间常数，并对充电动态曲线进行等间隔采样，只要选择三点以上信息，通过计算机解出3个联立方程，即可求得变压器绕组的直流电阻值．用计算机模拟和变压器实测证实了该方法的可行性以及测量结果的准确性，得出了用三点法动态测量各种大型电力变压器绕组直流电阻的规律．介绍了利用数据采集分辨率提高变压器直流电阻测量精度的方法．

The principle and process of dynamic testing the direct current resistance in transfor mer coil by 'three points method' is introduced. In the R, L's direct current charge period, the time constant is adjusted by computer technology, and charge dynamic curve is sampled. The transformer direct current resistance is gained only by solving three simultanous equations with three points information. The availability of the method is approved with experiment and compu ter simulation. Some principles of testing the direct current resistance in transformer coil by 'three points method' are presented. The method of measuring the resistance transformer coil by enhancing data sampling resolution is introduced.