宽量程电流互感器控制方法研究

当一次工作电流大范围变化时，电流互感器的测量误差将会发生较大的变化。为解决这个问题，在理论分析方面，通过对双级零磁通电流互感器磁动势补偿外加励磁回路特性的分析，建立完全可控的双级零磁通电流互感器状态反馈控制模型，考虑到电流互感器的励磁电流的非线性和不可直接提取特性，采用物理相似的方法，获得电流互感器励磁电流的相似电流，并通过自适应方法进行补偿，可以得到高准确度宽量程电流互感器：在实际测试过程中，一次电流从额定值的5％变化到120％，该电流互感器的测量误差不超过一次电流额定值100％时准确度为0．1级的测量标准。

RESEARCH ON THE CONTROL METHOD OF WIDE RANGE MEASUREMENT CURRENT TRANSFORMER

When the primary current of current transformer is changed in wide range, the errors of the current transformer are quite changed. In this paper, this problem is solved. In the theory, a completely controllable states feedback control model of zero flux current transformer is established by the analysis results of the zero flux current transformer magnetomotive force compensation and the active compensating loop chara-cteristics; because the exciting current of current transformer is indirectly extracted and nonlinear, a similarity current is obtained by physics similarity way; the high accuracy current transformer in wide range measurement is realized by a gain self-adaptive controller. In the experiment, when the primary side current is changed from 5% to 120% of the rating, errors of the wide range current transformer are less than the 0.1 grade standard at 100% rating.