Parameter Estimation of Power Transformer in Presence of Bad Measurement Data

Accurate parameter estimation of power system equipment's are very important for getting precise models which can be further used for protection settings and stability studies. This paper presents parameter estimation method for transformers using terminal measurements available from IEDs used for transformer protection. Identifying the equivalent circuit and estimating the transformer parameters including turns ratio, leakage reactance, shunt reactance and loss components are explained in this paper. The paper introduces practical scenarios where the measurement data is highly erroneous. These bad measurements need to be detected and corrected to improve the estimation accuracy. This paper put forward an accurate parameter estimation method that consider the presence of measurement errors. Identifying the bad measurement and correcting this bad data is also considered in this work. The estimation accuracy of the proposed methods is verified by simulation in PSCAD/EMTDC and testing in MATLAB.