Behavioral modeling of an inductive voltage transformer: Comparison between x-parameters and simplified volterra approaches

Power electronics devices in power systems have radically changed the operating conditions of electrical grids. Voltage and currents may be significantly distorted, and transducers suffer from weak nonlinear effects which are noticeable when they are employed for harmonic measurements. Therefore, using linear models for representing the behavior of these transducers may be not accurate enough. Simplified Volterra models under quasi-sinusoidal excitation have been recently proposed and applied to the characterization of inductive voltage transformers, thus achieving remarkable performance. Conversely, other suitable frequency-domain nonlinear models can be found in the literature. Among them, the X-parameters approach represents a promising alternative. In this paper, simplified Volterra and X-parameters approaches have been applied to model an inductive voltage transformer. The comparison shows that simplified Volterra model reaches similar accuracy over a wide range of input values albeit being defined by a considerably smaller set of coefficients.