Compensation of saturation in current transformer using modified Prony method

A novel scheme is proposed to fit and recover the primary current of the current transformer when transmission line fault occurs. Based on an iterative form of Prony method, the whole process require less than 1/4 of a cycle of base frequency. Due to the inconsistence of Prony method when embedded with noise and error, effective saturation detection and noise filtering algorithm using mathematical morphology transform are also applied in the scheme. Data obtained in a test system build by PSCAD software and practical experiments are both used to evaluate the performance of the proposed scheme.