Handling Initial Conditions in Vector Fitting for Real Time Modeling of Power System Dynamics

TL;DR

This paper introduces RTVF, an online modeling algorithm for real-time power system dynamics that extends vector fitting to handle initial conditions and is validated on synthetic and IEEE test systems.

Contribution

It generalizes the Time-Domain Vector Fitting algorithm for real-time power system modeling, addressing initial condition handling in dynamic environments.

Findings

Successfully models low frequency power system dynamics in real-time

Validated on synthetic and IEEE 39-bus test system

Handles initial-state decay in measured signals

Abstract

This paper develops a predictive modeling algorithm, denoted as Real-Time Vector Fitting (RTVF), which is capable of approximating the real-time linearized dynamics of multi-input multi-output (MIMO) dynamical systems via rational transfer function matrices. Based on a generalization of the well-known Time-Domain Vector Fitting (TDVF) algorithm, RTVF is suitable for online modeling of dynamical systems which experience both initial-state decay contributions in the measured output signals and concurrently active input signals. These adaptations were specifically contrived to meet the needs currently present in the electrical power systems community, where real-time modeling of low frequency power system dynamics is becoming an increasingly coveted tool by power system operators. After introducing and validating the RTVF scheme on synthetic test cases, this paper presents a series of numerical tests on high-order closed-loop generator systems in the IEEE 39-bus test system.