基于罗氏线圈的电阻点焊电流长时间检测

    Long-time Measurement of Resistance Spot Welding Current Based on Rogowski Coil

    • 摘要: 为实现电阻点焊电流的长时间准确检测并提高其工程适用性,分析了基于罗氏线圈的电流检测电路模型,提出了针对运算放大器不同失调特性的漂移补偿方法。根据叠加原理推导运放失调电压和失调电流对电流检测电路积分漂移的影响,根据运放不同的失调特性设计相应的漂移补偿方法。搭建实验平台,对检测电路理论分析和漂移补偿方法进行了验证。结果表明,被测电流与积分电压输出的理论关系分析较为准确,相对误差约为-5%;所述补偿方法可分别适用于运放两种不同的失调特性,实现电阻点焊电流的长时间检测。

       

      Abstract: In order to realize long-time accurate measurement of resistance spot welding current and improve its engineering applicability, the circuit model of current measurement based on Rogowski coil was analyzed, and drift compensation methods were proposed for different offset characteristics of operational amplifiers. The effect of offset voltage and offset current on the integration drift of current measurement circuit was deduced based on superposition principle, and different drift compensation methods were designed for different offset characteristics of operational amplifiers. Experimental platform was established to verify the theoretical analysis of measurement circuit and drift compensation methods. The results show that the theoretical analysis of the relationship between measured current and output integral voltage is accurate with about-5% of relative error. The compensation methods can be applied to two different offset characteristics of operational amplifiers to realize long-time measurement of resistance spot welding current.

       

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