A single machine infinite bus power system damping control design with extended state observer

Rittu Angu,R.K Mehta,Qingsong Ai

doi:10.1080/23311916.2017.1369923

Abstract

AbstractAs an alternative to power system stabilizer, this paper presents a robust controller known as extended state observer (ESO) for synchronous machine connected to an infinite bus (SMIB) power system. The ESO-based control scheme is implemented with an automatic voltage regulator in order to enhance the damping of low frequency power system oscillations so that the deviations in terminal voltage are compensated. The proposed ESO provides the estimates of system state as well as disturbance state together in order to improve the damping as well as compensate system efficiently in presence of parameter uncertainties and external disturbances. The closed-loop poles (CLPs) of the system have been assigned by the symmetrical root locus technique, with the desired level of system damping provided by the dominant CLPs. The performance of the system is analysed through simulating at different operating conditions. The control method is not only capable of providing zero estimation error in steady-state, but...

Highlights

Stability and control are one of the key elements in modern power system operations
This paper presents the effect of Extended State Observer-based control scheme to improve the stability and voltage regulation of a synchronous machine connected to an infinite bus (SMIB) power system through a transmission line
A design methodology for extended state observer (ESO)-based control scheme implemented with an Automatic Voltage Regulator (AVR) for a SMIB power system through a transmission line is presented

Summary

Introduction

Stability and control are one of the key elements in modern power system operations. Due to increasing growth in the consumption of electric power and complexity of the power system operations, viz. physical setups, interconnections, etc., a form of instability has emerged in the system in the form of power oscillations of small amplitude and low frequency (Basler & Schaefer, 2008). In addition to state estimation, such observer can be extended to deal with disturbances (external) and parameter or structure uncertainties (internal) that exists in almost all the physical systems and limit its performance (Gao, 2014; Xie & Guo, 2000). In Wang and Gu (2016) external disturbance has been considered by treating a resilient extended Kalman filter as a real time state estimator for unavailable state variables, but it is based on transient stability of the power system. The design of an ESO is presented for a single machine infinite bus (SMIB) power system to improve the small signal stability and voltage regulation of the system. K1 through K6 are parameters depending on the operating condition of the power system and their deduction can be found in (Anderson & Fouad, 2003)

ESO based control scheme

Conclusion