基于Rogowski线圈的中频点焊次级电流检测装置

Secondary current detecting device of medium frequency resistance spot welding based on rogowski coil

为了更准确的检测焊接电流以保证焊接电流控制精度,设计了次级电流检测装置。针对中频电阻点焊焊接电流的特点确定了Rogowski线圈的参数,分析了Rogowski线圈基本调理电路的各种误差,提出了对称补偿的调理电路,研究了测量装置的性能及稳定性。测试结果表明,设计的对称补偿调理电路有效地克服了传统积分电路的长时间积分漂移以及宽范围测量非线性问题,在整个测量范围内有良好的线性度及精度,可实现大焊接电流的长时间准确稳定测量。同时,设计的电流检测装置体积小,安装方便,成本低,可以广泛的应用于中频电阻点焊控制器。

In order to detect welding current better and improve welding quality of resistance welding,the secondary current detecting device of medium frequency resistance spot welding was designed based on Rogowski coil. The parameters of Rogowski coil were determined according to the characteristics of welding current. The errors of Rogowski coil basic integration circuit were analyzed. A symmetrical compensation circuit was designed. Test results show that the symmetrical compensation circuit effectively overcomes the basic integral circuit of the integrated drift and nonlinear problems. The current detecting device can measure real-time welding current accurately and stably. What's more,compared with other welding current detecting devices,the current detecting device is smaller in size,more convenient in installation and lower in cost.