Distributed implementation of an augmented state dynamic estimator

Load models are commonly approximated by fixed impedance type loads when formulating dynamic simulations. This is an acceptable approximation when using dynamic simulation for a specific initial operating condition and the study runs for a brief period typically to check system stability. When implementing an on-line dynamic estimator such assumptions may not be viable due to the load dynamics which are not typically known. Another difficulty is related to the sheer size of the problem when a large scale system is considered with several generators. This paper addresses these problems by extending the state vector to include network variables, thus eliminating the need to model loads and also by implementing a distributed yet synchronized solution algorithm that facilities simultaneous solutions by multiple areas. Previously studied Unscented Kalman Filter (UKF) is used and the proposed method is tested on the New-England 37-bus system.