Abstract
Due to the size and complexity of modern electrical power networks and the cost of monitoring and telecommunication equipment, it is unfeasible to fully monitor the system state. For this reason state estimation techniques are used. With strategically placed measurements, estimation techniques can determine the parameters at unmonitored locations. Fundamental frequency state estimation is now a standard tool in modern power systems. The emission and immunity levels of modern electrical equipment are different to that of the past, and this has resulted in power quality issues have become important. Knowledge of the source and location of the disturbances is desirable so that remedial action can be taken promptly. Recent contributions have extended the concept to: harmonic state estimation (HSE) and identification of harmonic sources, transient state estimation (TSE) and voltage sag state estimation (VSSE), which are all types of power quality state estimation (PQSE). This paper provides an overview of the stateβofβtheβart techniques currently available for PQSE in a large electrical power system. Copyright Β© 2009 John Wiley & Sons, Ltd.