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.