Achieving Enhanced Phasor POD Performance by Introducing a Control-Input Model

In this paper, an enhancement to the well known Phasor Power Oscillation Damper is proposed, aiming to improve its performance. Fundamental to the functioning of this controller is the estimation of a phasor representing oscillations at a particular frequency in a measured signal. The phasor is transformed to time domain and applied as a setpoint signal to a controllable device. The contribution in this paper specifically targets the estimation algorithm of the controller: It is found that improved estimation accuracy and thereby enhanced damping performance can be achieved by introducing a prediction-correction scheme for the estimator, in the form of a Kalman Filter. The prediction of the phasor at the next step is performed based on the control signal that is applied at the current step. This enables more precise damping of the targeted mode. The presented results, which are obtained from simulations on a Single-Machine Infinite Bus system and the IEEE 39-Bus system, indicate that the proposed enhancement improves the performance of this type of controller.Achieving Enhanced Phasor POD Performance by Introducing a Control-Input ModelacceptedVersio

Impact of Model Detail of Synchronous Machines on Real-time Transient Stability Assessment

peer reviewedIn this paper, it is investigated how detailed the model of a synchronous machine needs to be in order to assess transient stability using a Single Machine Equivalent (SIME). The results will show how the stability mechanism and the stability assessment are affected by the model detail. In order to identify the transient stability mechanism, a simulation with a high-order model was used as reference. The Western System Coordinating Council System (WSCC) and the New England & New York system are considered and simulations of an unstable and a stable scenario are carried out, where the detail of the machine models is varied. Analyses of the results suggest that a 4th -order model may be sufficient to represent synchronous machines in transient stability studies