Remedial Action Scheme based on Automatic Load Shedding for Power Oscillation Damping

Abstract

This paper presents an algorithm for automatic load shedding as a Remedial Action Scheme (RAS) for power oscillation damping. The algorithm computes the exact amount of power for the load shedding in all buses and then detects the critical areas in the system. Therefore, the trip actions are only in the areas where are necessary. In addition to this, the RAS is equipped with an oscillation monitoring stage since the system presents oscillatory transitions. The proposed RAS methodology is based on the online computation of the PV curves and the voltage stability margin for calculating the amount of power to trip and used a load shedding strategy based on modal participation factors to identify the most critical areas. On the other hand, the algorithm identifies ringdown data for the detection of oscillations, and Prony's analysis monitors the damping of oscillations to determine online if the load disconnection has the desired effect. Performance evaluation of the proposed scheme has been made on a 12-bus network and, the results show excellent damping of oscillations for critical contingencies and an increase in the stability margin of the whole power system.