A New Method for Over-voltage Online Monitoring Based on Chain Parameters

This paper presents a new method for over-voltage online monitoring based on chain parameters (ABCD parameters) of the equipments in the substation. The method models the potential transformer (PT), secondary cables and voltage divider as several two-port networks in cascade by means of their ABCD parameters. Adoption of this model can derive the over-voltage waveform of the high-voltage port of the PT from the voltage signal of the secondary device by means of time domain recursive convolution. The two-port ABCD parameters model of a lOkV PT is built by using this method. The comparison between the calculated results and measured data verify the feasibility of this method.