A Constrained Formulation for Simultaneous Line Parameter Estimation and Instrument Transformer Calibration

TL;DR

This paper introduces a new constrained optimization framework that simultaneously estimates line parameters and calibrates instrument transformers using PMU data, leveraging domain knowledge to address interdependency issues.

Contribution

The authors propose a novel method that integrates power system constraints to perform joint line parameter estimation and instrument transformer calibration from PMU data.

Findings

Effective with simulated and real PMU data

Reduces hardware needs and offline calibration

Improves accuracy of line parameter and transformer calibration

Abstract

The process of calibrating instrument transformers (ITs) has been greatly simplified by using phasor measurement unit (PMU) data since this process eliminates the need for (a) additional hardware, and (b) taking ITs offline. However, such simplification comes at the cost of knowing the line parameters, whose estimation using PMU data in turn requires calibrated ITs. To solve this interdependency problem, we propose a novel framework that incorporates power system domain knowledge as constraints to perform simultaneous line parameter estimation and IT calibration. We demonstrate the effectiveness of our approach with simulated and real PMU data as well as for a power system application that uses both PMU data and line parameter information.