Real-time transformer parameter estimation using terminal measurements

Transformer failures in transmission and distribution systems can cause substantial service interruptions and take an extended period of time to recover from. Situational awareness in a proactive way about the state-of-health of transformers can greatly help operators and asset managers prepare for emergencies and optimize scarce operations and maintenance resources. A method is introduced to estimate transformer fundamental parameters including turns ratio, series winding resistance, series leakage inductance, shunt magnetizing inductance, and shunt core loss resistance. This enhanced technique does not require transformer outage and/or specialty sensors. Rather, it utilizes the two-terminal synchronized voltage and current measurements which can be readily retrieved from the transformer Intelligent Electronic Device (IED). The proposed method is able to estimate a single phase transformer parameters in less than a cycle. The benefits and caveats of different solutions are compared including the accuracy and convergence rate.