基于PREISACH理论的电流互感器建模研究

提出了一种新型电流互感器（CT）数字化模型。该模型由CT电磁感应方程和基于Preisach理论的新型铁心磁化模型组成：基于Priesach理论的WIPING—OUT特性，提出了确定铁心运行所在磁化曲线的方法，并在新坐标系下分离Preisach函数的变量，得到了不同情况下铁心磁通密度的计算方法，由此建立了铁心磁化模型；提出了一种新的寻解算法，通过该算法将铁心磁化模型同CT电磁感应方程相耦合，建立了CT数字化模型。该模型只需极限磁滞回环下降支、一次电流和二次负荷等少量易被直接测得的参数，即可较准确地仿真铁心内部磁化过程，具有实现简便，仿真精度高等特点。采用文中CT模型对保护CT的饱和特性进行了仿真研究，仿真结果和实测数据的比较验证了模型的有效性。

RESEARCH ON CT MODELING BASED ON THE PREISACH THEORY

This paper presents a new digital CT model. The CT model is constructed with CT electro-magnetic equations and a new ferocore model based on Preisach theory. Firstly, based on the WIPING-OUT property of Preisach theory, this paper proposes a method to determine magnetizing curve on which the ferocore is working; and by separating the variables of Preisach function, acquires the expressions of magnetizing curve; from these, constructs the ferocore model. And then, a new method to search solutions is proposed; by this method, the ferocore model and electro-magnetic equations of CT are coupled to construct the CT model. The CT model can simulate magnetization process of ferocore precisely by knowing only some easily acquired parameters such as limiting hysteresis loop, primary current and secondary burden; therefore, its implementation is very convenient. Some research on CT saturation characters is done based on this model. Comparison between measurement data and simulation results shows the validity of this CT model.