降低钳式微电流传感器气隙影响的方法  

Study of Principle and Method to Depress the Air-gap Effect for the Clamp-on Micro-current Transducer

作　　者：陈攀[1] 孙才新[1] 姚陈果[1] 肖立[1] 米彦[1] 

机构地区：[1]重庆大学高电压及电工新技术教育部重点实验室,重庆400044

出　　处：《高电压技术》2006年第4期31-33,50,共4页High Voltage Engineering

摘　　要：通过带气隙穿芯式电流传感器等效电路模型分析了其幅频特性及气隙对磁阻、自感、互感、低频特性等的影响。气隙的存在提升了传感器的低频下限,使其频带变窄,同时线圈所感应出的微弱电压信号因易受干扰而很难准确测量。因此提出通过后续电子电路降低气隙影响的新方法并用saber仿真了传感器幅频特性。实测表明:传感器低频下限改善极大,通频带宽、线性度好、灵敏度高。In recent years, with the development of online monitoring technology for power equipment, the microcurrent （μA, mA） transducer has been applied more broadly. Owing to the isolation characteristics between the primary winding and the secondary winding and no effect to circuit connection in power system, non-contact passing through micro-current transducer becomes the first choice of on-line monitoring for HV electric equipment. Since the low limiting frequency of the clamp-on micro-current transducer is raised by effect of the gap, many improvements have been done towards traditional clamp-on transducer to depress the effect of the gap. So there is a conflict between the application convenience and the bandwidth of the passing through clamp-on micro-current transducer. The amplitude-phase characteristic of the transducer and mutual inductance of the transducer are analyzed by the effect of the gap to the magnetic resistance, inductance and the equivalent model of passing through clamp-on micro-current transducer. Because of the gap, the lower limiting frequency of the transducer increase and the bandwidth narrow down, meanwhile the voltage induced by the coil of the transducer is so feebleness and easy to be interfered that is difficult to be measured accurately, which is a well-known difficult problem in the portable type measurement of the low-frequency feeble current signal. In this paper, a new method to reduce the effect of the gap in the transducer is introduced with the design principle supplied, and the amplitude-frequency characteristic of the transducer is simulated by Saber. The academic lower limiting frequency of the transducer is nearly zero and the upper limiting frequency is infinity. The test of the current transducer shows that the low limiting frequency of the transducer is improved, which can be use in most systems to reduce the effect of gap to the amplitude-frequency characteristic of transducer with broad pass-bandwidth,high linearity and high sensitivity.

关 键 词：电流传感器 气隙 钳式 宽频带 幅频特性 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]