弧焊电源变压器绕组温升快速测量的新方法

A New Method to Measure the Temperature Increase of the Transformer Winding of Arc Welding Power Source

针对弧焊电源变压器绕组温升检测需要进行绕组电阻值精确测量的问题，本文在恒流源法和双臂电桥法的基础上，利用计算机快速测试的特性，提出了比较法的测量方案。由于孤焊电源变压器绕组可等效为电感Ｌ与电阻Ｒ的串联电路，当一恒定电流流过时，电流达到稳定的时间较长。根据阻尼振荡的原理，Ｒ－Ｌ与一电容Ｃ构成欠阻尼的二阶系统，可使由电感引起的过渡过程的稳定时间缩短在一秒钟以内，从而实现了对绕组温升的快速、准确测量。

To detect the temperature increase of the transformer winding of are welding power source, the resistance of the winding should be measured precisely. For this purpose,a comparison method based on the constant-current source method and double arm bridge method is presented in this paper. Since the winding is equivelent to a series connection circuit of inductance L and resistance R, the transition process is unstable when a constant current is imposed. According to the principle of damping oscillation, a capacity C and the R-L can form a 2-grade under dampering system.Thusd the time for stablizing the transition process is shortened to within 1 second, and the precise measurement can be achieved quickly.