电流互感器自动化检定系统二次负荷测试及分析

Measurement and analysis on secondary burden of automatic testing system in current transformer

简介了互感器校验仪法及伏安相位法两种二次负荷测试方法,并对电流互感器自动化检定系统各工位的二次负荷进行了测试。测试结果表明,二次回路导线的阻抗均超过60 mΩ,最大值达到了100 mΩ;当电流负载箱置2.5 VA时,测试的二次负荷实际值与额定值的偏差绝大多数超过5%,最大偏差达到了19%。发现了二次回路继电器接点的接触电阻和二次自动接线机构压接不紧是主要原因,分析了其对二次负荷、互感器误差的影响。最后提出了具体的改进措施,减小了二次回路的阻抗,提高了互感器的检定质量。

This paper briefly introduces two testing methods of secondary burden on transformers test set and volt - ampere phase, and the secondary burden of working stations is measured in the automatic testing system of current transformer. The result shows that the wire resistance is more than 60Ω mon average, 100 mΩ up to the max resistance value and most of relative errors between the actual burden and the nominal burden exceeds 5% , 19% up to the max relative error while the volume of the burden box is 2.5 VA. The fact that contact resistance of relays and poor contact between terminals of current transformer and connection mechanism is the main reason. It analyses the influences on secondary burden and error of current transformer. Finally, some improvement measures are suggested for the system, which decreases secondary loop impedance and improves the test quality of current transformer.