电流互感器自动化检定系统二次负荷测试及分析.doc

电流互感器自动化检定系统二次负荷测试及分析 丁涛, 邵淮岭, 何志强，张伟, 李华东, 李蕾 (国网河南省电力公司电力科学研究院，郑州 450018) 摘要：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60mΩ，最大值达到了100mΩ；当电流负载箱置2.5VA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。 关键词：电流互感器；自动化检定系统；二次负荷；测试；分析；改进 中图分类号：TM933.4 文献标识码：A Measurement and analysis on secondary burden of automatic testing system in current transformer Ding Tao, Shao Huailing, He Zhiqiang, Zhang Wei, Li Huadong, Li Lei (State Grid Henan Electric Power Research Institute, Zhengzhou 450018, China) Abstract: 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 60mΩ on 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 2.5VA. 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. Keywords: current transformer, automatic testing system, secondary burden, measurement, analysis, improvement0引言 计量用低压电流互感器自动化检定系统(以下简称系统)近几年在省级计量中心逐步得到了应用。该系统把互感器的检定技术和自动化流水线技术、控制技术相结合，实现了低压电流互感器的大批量自动检定任务，提高了劳动效率，降低了劳动强度和生产成本。系统最显著特点是自动化传输和自动拆接线。电流互感器一次接线靠气动穿杆自动化拆接线装置完成，二次接线靠触针定位系统来自动完成 [1-2]。大批量的测试发现，二次端子的接线质量对被试互感器的误差影响较大。 JJG313-2010测量用电流互感器中规定“电流负荷箱在额定频率50Hz，额定电流的20%~120%，环境温度(20±5)C时，电流负荷(与规定的二次引线电阻一并计算)的有功分量和无功分量的相对误差不得超过±3%”，国家电网公司企业标准Q/GDW1573-2014中规定“被试电流互感器二次端子实际接