集磁式光学电流传感器磁场与温度场耦合分析

Electromagnetic-Thermal Coupled Analysis of Optical Current Transducer With Magnetic Concentrator

集磁式光学电流传感器(optical current transducer,OCT)磁场分布受温度影响,建立其磁场与温度场耦合仿真模型有助于提出温漂补偿措施。在分析温度对铁磁材料磁滞回线和集磁环气隙长度影响的基础上,建立了集磁式OCT三维有限元模型。经过多次电磁场-热场-磁致回线与气隙长度修正的迭代求解过程,实现集磁式OCT在测量稳态直流电流时磁场与温度场的耦合仿真,确定了温升、磁场强度、环境温度和母线电流之间的数学关系。根据仿真结果提出一种磁场强度基本不随温度变化的补偿措施。最后通过实验验证了仿真模型和补偿措施的有效性。

Magnetic field distribution of optical current transducer （OCT） is affected by temperature, so it＇s necessary to establish the electromagnetic-thermal coupled simulation model. Based on the analysis of thermal effects on hysteresis loop and air gap length, a three dimensional finite element method model of OCT with magnetic concentrator was built. After several iterative solution process such as electromagnetic field - thermal field - hysteresis loop - air gap length, the electromagnetic-thermal coupled simulation when measuring direct current was achieved. The relationship between temperature rise, magnetic field intensity, environment temperature and current was determined. A new design of air gapped amorphous core with stable temperature characteristics was proposed based on simulation results. Experimental results show that the electromagnetic-thermal coupled simulation method and the design with stable temperature characteristics are useful.