Development of electrical circuit model for an optical potential transformer

Producing equivalent circuit models for potential transformers is considerably important for the relay testing and relay performance evaluations in EMTP transient studies. Magnetic transformer models have been used for many years and re-developed in time for different applications. Optical potential transformers (OPT) that produce digital and analog signals have been recently developed and have become available for power system applications. In this paper, equivalent circuit model for OPT has been developed and presented for analog output. Frequency response characteristics of OPT was obtained by using laboratory test setup. Straightforward mathematical method used the test results for developing a new OPT model. The developed circuit was validated through the frequency response test data. Results show that the developed model can be used as a legitimate OPT model.