A measurement-based approach for power system instability early warning

Feifei Bai,Evangelos Farantatos,Yong Liu,Navin Bhatt,Kai Sun,Xiaoru Wang,Alberto Del Rosso,Yilu Liu

doi:10.1186/s41601-016-0014-0

Abstract

Early warning of impending instability in a power system under disturbance conditions is important for preventing of system collapse. A measurement-based approach is proposed to assess the potential power system transient instability problem under cascading outages. Where a measurement-based index is obtained as the estimation accuracy of a linear autoregressive exogenous (ARX) model to estimate the dynamic response of the power system and indicate the system stability to some extent after a disturbance. The proposed approach was verified using a set of marginally stable cases in a 179-bus WECC equivalent power system. Then the instability early warning threshold for this system is obtained as 0.44.

Highlights

With the interconnections of power system increasing, the instability assessment is becoming more and more important for safe operation of power systems
Prior to joining UTK/Oak Ridge National Laboratory (ORNL), she was a Professor at Virginia Tech. She led the effort to create the North American power grid Frequency Monitoring Network (FNET) at Virginia Tech, which is operated at UTK and ORNL as GridEye
Bhatt (F’09) received a BSEE degree from India, and MSEE and PhD degrees in electric power engineering from the West Virginia University, Morgantown, WV, USA. He works at EPRI since July 2010, where his activities focus on R&D in the smart transmission grid, and transmission operations & planning areas

Summary

Introduction

With the interconnections of power system increasing, the instability assessment is becoming more and more important for safe operation of power systems. If power system is close to the stability limit, actions must be taken by system operators to identify critical states. The analysis of system dynamic response during or after the disturbance is very important to indicate the potential instability of the power system [4]. The conventional methods of power system analysis are based on numerical solution of system differential algebraic equations. These numerical methods need more detailed representation of the power system but they are not suited for online application of stability.

Methodology of the proposed approach

Method for instability awareness

Conclusion