电子式电流互感器中的关键技术

Key Technology of Electronic Current Transformer

详细分析了IEC6 0 0 4 4 8《ElectronicCurrentTransformer》中规定的光学TA及空芯TA目前存在的关键技术问题及解决方案。运用矩阵光学理论 ,提出了采用永久磁体作为参考源应用于光学TA中的比较测量法 ,实验表明该法可实时补偿随环境因素改变的材料Verdet常数及线性双折射。还介绍了一种基于印刷电路板的空芯线圈新结构 ,其二次绕组无需手工绕制和电阻调整 ,额定电流 2 0A时 ,准确度 0 .2级 ;额定电流≥ 30 0A时 ,准确度 0 .2S级。采用低功耗电子技术后空芯TA测量准确度 0 .2级时高压侧电路功耗 <5 0mW。

The main technology problems of optical and air core current transformers defined by IEC 60044-8《Electronic Current Transformer》 and its solution are analyzed in detail. Using permanent magnet as reference source, a method of comparative measurement is proposed for optical current transformer, based on the theory of matrix optics. The experiment shows that the influence of Verdet constant of material and linear birefringence caused by varying environmental conditions can be real-timely compensated by this method. A new structure of Rogowski Coils based on printed circuit board is introduced, it is not necessary to wound secondary winding; by hand and to adjust resistance. Its accuracy reaches 0.2 class when primary current is 20 A, and reaches 0.2 s class when primary current is 300 A or more. By using low power technology, the power consumption of Rogowski Coil current transformer on the high voltage side is below 50 mW while its accuracy is at 0.2 class.