电磁式电流互感器误差矢量代数分析法

Vector algebraic analysis method for inductive current transformers error

针对目前互感器相关参考书中电磁式CT误差模型采用向量几何法进行建模,存在的理论与逻辑性不强、结论模糊、表述不清晰等问题,通过电磁式互感器CT等效电路模型,依据电路及计量误差理论,采用矢量代数学分析方法建立了互感器复(数)误差数学模型;通过复(数)误差不同代数表达式,合理引申出互感器比差、角差理论公式,据此对电磁式CT误差特性及影响因素、运行条件下误差影响量及对电能计量产生的附加误差进行了定量系统分析。研究结果表明,矢量代数建模及分析法简单、严谨,逻辑性强,对电磁式VT、VT二次回路压降分析也同样适用,是对电磁式互感器误差理论的完善,也是互感器"低校高"误差间接测量法及计算机误差仿真的理论基础。

Aiming at the proldem of illogical theory,vague conclusion,and unclear expression in an electromagnetic CT error model based on vector geometry error modeling reported in literature,an complex error mathematic model for transformer was developed based on vector algebra analytic method by utilizing transformer CT equivalent circuit model and the theory on circuit measurement error. Based on different algebra expressions for complex error,formula for the ratio difference and the angular difference of the transformer were rationally derived,the error characteristics and the influencing factors of the CT transformer,the error effect of the transformer operating state,and the additional error to the electric energy measurement were analyzed systematically and quantitatively. The results show that the vector algebra modeling and analytic method is a simple,rigorous,and logical method for transformer error analysis,and can be applied to voltage drop of the VT secondary circuit too. The proposed method,therefore,can enhance the error theory of electromagnetic transformer,and establish a theoretical basis for the indirect measuring method of calibrating high voltage transformers with low measuring voltage for computer simulations.