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Although large scale simulation models may better represent the behavior of practical power systems, they are time-consuming and turn out to be impractical for some desired applications, particularly when the focus of the study is on only a small portion of the entire system and the use of a complete model would dramatically increase the computational effort and time. Therefore, network equivalent models can be used in this case to facilitate and accelerate the completion of the required analysis related to the specific subsystem. In this sense, and considering here small and large sample networks, the evaluation of static equivalents derived from popular Ward and REI reduction methods is presented in this paper. The performance of the reduced networks is assessed under the N-1 contingency criteria, and takes into account not only the base case condition but also post contingency response with the whole set of lines in the particular area of study. Obtained equivalents are compared in simulation in terms of deviations from the original system and average computational time needed to complete the involved power flow calculations.

In this work a state-feedback controller for pole placement is presented. In addition, a model predictive control (MPC) to minimize the magnitude of the controller input is also presented. The MPC use an observer to estimate the states of the plant and optimize a cost function to maintain the input within a pre-defined limit. The proposed approach is validate trough nonlinear simulations using the equivalent Nordic power system and where a Static Var Compensator is used as actuator. Wide-area signals from Phasor Measurement Units (PMUs) are used to improve the damping of the system.

In this paper, an investigation into the use of Flexible ac Transmission Systems (FACTS) devices to aid damping of low-frequency inter-area oscillations in longitudinal power systems is presented. A linear model of VSC-based FACTS devices that takes into account the dynamics of dc links is developed and incorporated into a production-grade software for small signal analysis of large power systems. Based on this representation, a unified framework for modal power oscillation flow studies is then developed to analyze the sensitivity of modal behavior to FACTS control action. With this method, the transmission corridors and system parameters having a large contribution to critical system oscillations modes are determined. The method is particularly well suited for investigating inter-system oscillations in large-scale power systems with embedded FACTS controllers The utilized methodology is tested on a practical 45-machine Mexican system that includes several major static VAR compensators. Control mode implementations are discussed and tested and comparisons with existing technologies are presented.

In this work, real-time evaluation and steps towards implementation of three different types of power oscillation damping controllers (POD) for fast power electronic devices such as FACTS (flexible AC transmission systems) have been done. The performance of classical POD controllers (lead-lags and phasor estimators) are compared with an advanced adaptive approach. The prerequisite for achieving optimal results in damping of electromechanical oscillations is the availability of remote signals through wide-area monitoring and control (WAMC) platforms discussed here. Achieved results are demonstrated on a dedicated real-time hardware platform.