FIR modeling of voltage instrument transformers from frequency response data

This paper presents a method for Finite-Impulse-Response (FIR) modeling of voltage instrument transformers. The method is based on Wiener filtering and measurement of the transformer response in the frequency domain using a low frequency network analyzer. The proposed method allows, through the digital filtering operation, an accurate simulation of the transformer response to transient excitation. Furthermore, the proposed approach to the modeling of the system function allows unequal spacing of the frequency samples. The theoretical analysis is confirmed with measurements in time domain, using the recurrent surge generator.