中文摘要：

钳式微电流传感器具有工程安装方便的优点,在电气设备绝缘监测中应用广泛。由于安装过程中开口气隙的不一致,加之野外运行温差较大造成信号处理电路温漂和参数变化,致使在实验室严格调试的高精度微电流传感器,运行时会产生较大误差,并且各个传感器的变比也会偏离设计值。为此,提出了基于标准电流注入的微电流传感器在线定标方法,运行时在原边注入1个标准的定标电流信号,该信号的频率应避开传感器工作电流所含有的工频和一定幅值的谐波频率;然后从传感器信号处理电路的输出端得到定标信号,进而计算实际标度,根据此标度就可计算出实际泄漏电流。实验得到的传感器精度可以达到±0.05%,实验室和现场实验验证了提出方法的有效性和准确性。

英文摘要：

Because air gaps of transducers are inconsistent during installation, and the parameters of their signal ~0rocessing circuits change wilh large temperature difference in operating environment, the resultant errors in operation cannot be neglected, even as for a micro current transducer precisely debugged in laboratory, and that the ratio of each sensor will deviate from the designed value. Consequently, we proposed an on-line calibration method for an air-gapped micro-current transducer based on a standard current injection. A given current signal with the specific frequency was firstly injected in the primary coil of the transducer in operation, and the frequency should be largely different from the fundamental and harmonic frequencies, whose amplitude could not be neglected, in the working current of the transducer. Then the corresponding output signal of the processing circuit of the transducer could be obtained, so that the real scale could be calculated and applied to the calculation of the primary leakage current. The transducer accuracy of experiment could be up to±0.05 %. The wdidity and accuracy of the proposed method was verified by laboratory and field testing.