Title:  Electrical Power System Current and Voltage Instrumentation Channel Error Correction using Unconstrained Weighted Least Square Dynamic State Estimation

Committee:

Dr. Sakis Meliopoulos, ECE, Chair , Advisor

Dr. Thomas Habetler, ECE

Dr. Daniel Molzahn, ECE

Dr. Santiago Grijalva, ECE

Dr. Adegboyega Oyelere, Chemistry

Abstract: The objective of this dissertation research is to study the problem of error generation in the Current Transformer (CT) and Voltage Transformer (VT) Instrumentation Channels, respectively, and then to investigate the application of a Dynamic State Estimation (DSE) technique to correct for the error generation in each case.  The dissertation research was conducted as an early stage or a proof-of-concept endeavor and focuses on conventional instrument transformers. This dissertation thus presents the detailed development and performance evaluation of DSE-based error correction algorithms for conventional instrument transformer instrumentation channel applications – that is, current transformer and voltage transformer applications. The error correction algorithm continuously obtains measurements of the instrumentation channel output, and then uses the detailed mathematical model of the instrumentation channel along with the Unconstrained Weighted Least Squares (UWLS) DSE technique to provide sample-by-sample estimates of the CT or VT primary quantity. The algorithm therefore represents a Model-Based Optimization (MBO) process that provides the state variable estimates based on continuously fitting the instrumentation channel measurements to the detailed model on a sample-by-sample basis. The error correction algorithm represents an advanced instrumentation channel functionality provision for hybrid or fully digitalized power system substation architectures. And, the algorithm can be implemented using the software options of the Merging Unit (MU), which is an operationally integral component of the instrument transformer instrumentation channel design in hybrid or fully digital substations.