# Development and Applicability of Online Passivity Enforced Wide-Band Multi-Port Equivalents For Hybrid Transient Simulation

## TL;DR

This paper introduces an online passivity enforced method for developing frequency dependent network equivalents that enable real-time hybrid transient simulations of power systems with unknown parameters.

## Contribution

It proposes a novel online recursive least squares algorithm for passivity enforced FDNE development applicable in real-time power system simulations.

## Key findings

- Successfully verified on IEEE 39 and 68 bus power systems.
- Achieves accurate, stable, and passive network equivalents in real-time.
- Handles unknown network parameters effectively.

## Abstract

This paper presents a method for developing single and multi-port frequency dependent network equivalent (FDNE) based on a passivity enforced online recursive least squares identification algorithm, which identifies the input admittance matrix in z-domain. Furthermore, with the proposed architecture, a real-time hybrid model of the reduced power system is developed that integrate transient stability analysis and FDNE. Main advantages of the proposed architecture are, it identifies the FDNE even with unknown network parameters in the frequency range of interest, and yet can be implemented directly due to discrete formulation while maintaining desired accuracy, stability, and passivity conditions. The accuracy and characteristics of the proposed method are verified by implementing on two-area, IEEE 39 and 68 bus power system models.