交流接触器电压暂降非单调抗扰特性分析

交流接触器的电压暂降抗扰特性可能会出现非单调性,使得其电压暂降免疫评估出现错误。为分析产生交流接触器电压暂降非单调抗扰特性的原因,文中建立了计及控制线圈电气特性的交流接触器详细数学模型。通过求解模型,获得了电压暂降下控制线圈电流和弹簧压缩距离,从理论层面分析了交流接触器的电压暂降抗扰特性。电压暂降发生时,控制线圈电流中可能会出现非周期分量,而非周期分量的大小决定了控制线圈电磁力的大小,从而决定了电压暂降抗扰特性。研究表明:控制线圈电流分周期分量与电压暂降起始角密切相关,是产生交流接触器电压暂降非单调抗扰特性的根本原因。最后,通过对交流接触器的实验测试,验证了理论分析结果的正确性。

Analysis of Non-monotonic Voltage Sag Tolerance Characteristics of AC Contactors

The non-monotonic voltage sag tolerance characteristics may lead to the wrong evaluation of voltage immunity of AC contactors. To analyze the non-monotonic voltage sag tolerance characteristics of AC contactors, this paper developes a detailed mathematical model including the electrical performance of the control coil. By solving the model, the current of control coil and the spring compression distance of AC contactor can be calculated. The voltage sag tolerance characteristics of the AC contactor are analyzed in theory. The non-periodic current will appear in the control coil during the voltage sag. The non-periodic component decides the electromagnetic force produced by the control coil, which determines the voltage sag tolerance characteristics. The research shows that the non-periodic current in the control coil is dependent on the voltage sag starting angle. It is the root cause of non-monotonic voltage sag tolerance characteristics. Finally, the experimental results show the correctness of the theoretical analysis.