Development of Floquet Multiplier Estimator to Determine Nonlinear Oscillatory Behavior in Power System Data Measurement

Namki Choi,Byongjun Lee,Hwanhee Cho

doi:10.3390/en12101824

Abstract

Measurement-based technology has been developed in the area of power transmission systems with phasor measurement units (PMU). Using high-resolution PMU data, the oscillatory behavior of power systems from general electromagnetic oscillations to sub-synchronous resonances can be observed. Studying oscillations in power systems is important to obtain information about the orbital stability of the system. Floquet multipliers calculation is based on a mathematical model to determine the orbital stability of a system with the existence of stable or unstable periodic solutions. In this paper, we have developed a model-free method to estimate Floquet multipliers using time series data. A comparative study between calculated and estimated Floquet multipliers has been performed to validate the proposed method. The results are provided for a sample three-bus power system network and the system integrated with a doubly fed induction generator.

Highlights

Over the past few decades, power systems have experienced significant changes regarding the amount of power consumed as well as the complexity of the network
This paper focuses on the feature of periodic stability of the power system dynamics
We compared a proposed method of estimating the Floquet multiplier with time series data and a calculated Floquet multiplier based on a mathematical model

Summary

Introduction

Over the past few decades, power systems have experienced significant changes regarding the amount of power consumed as well as the complexity of the network. Voltage instabilities tend to occur in power systems that are heavily loaded or in faulty condition. There are various indicators of voltage instability, which are determined by the generator, load dynamics, and network structure [1]. Nonlinear oscillatory behaviors are usually noticeable even before the voltage collapse occurs. These oscillatory behaviors can be observed with high-resolution devices. After detecting nonlinear oscillatory behavior, the type of oscillation needs to be determined to check whether the condition will be harmful to the power system

Results

Discussion

Conclusion