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A genetic algorithm to find the optimal location and sizing of shunt FACTS devices is used to optimize a multi-objective problem, which is formed by first swing stability margin and voltage stability margin. The first swing stability margin is determined by analyzing the output results of the conventional time domain simulation method, basically, machine angles and speeds. On the other hand, the voltage stability margin or loading margin is calculated using continuous power flow. The analysis is done for critical contingencies that cause problems both for voltage stability and first swing stability margin. In order to achieve the objective proposed, the location and sizing of shunt FACTS devices are optimized simultaneously. The method is tested on a 68 bus system.

This paper proposes a procedure of adjustment of settings of overcurrent protections for distribution networks when distributed generation is incorporated in. Then, the procedure establishes the required steps to detect faults, isolate faulty zones, detect and create possible island modes, and finally restore the total operation of the system in order to meet the objective of protection's adaptation. So, the procedure identifies the required adjustments for the protection devices involved in the system. This paper also proposes a computational method to adjust automatically the settings of protective devices in an interactive simulation environment, which gives information about the system topology and its protection devices as well as messages in each step of the protection procedure after a change in the system, is detected. Finally, a conceptual architecture that would be required for the implementation of the independent adaptive protection scheme is presented.

This paper proposes the identification of electromechanical modes based on signals obtained from Phasor Measurement Unit using a moving time window and a growing window during the post-disturbance state, considering both Prony's method and the Hankel's total least square method. Results show that the two methods can be used for online identification of oscillation modes; however, the moving window must not be shorter than the period of the lowest frequency determined by offline Eigenvalues analysis.

The technological development and enhancement of new strategies related with Wide Area Measurement and Control Systems (WAMCS) is playing a key role with large interconnected power systems in order to assure stability under Low Frequency Oscillations (LFO). In this document a hierarchical intelligent controller scheme for multi-machine systems is presented with the purpose to maximize the damping factor of intra-area and inter-area oscillations combining the principles of Fuzzy Logic Control and Multi-Agent Systems (MAS) architecture. The controller design takes advantage of the controllability and observability definitions to obtain the optimal location of the local Power System Stabilizers (PSS) and the Phasor Measurement Units (PMU) where the local PSS has been modeled with fuzzy logic as well. An algorithm to measure the damping of any signal is developed and used as PMU measurement in tie-lines. The time-domain response of the designed controller is tested in a power benchmark system demonstrating its adaptability and performance.

This paper presents a novel method for finding coherent groups of generators in large power systems, based on graph partitioning and clustering methods commonly used in other areas like image processing and gene expression analysis. First, the power system is modeled as a graph in order to obtain a maximum spanning tree that represents the strongest connections between generators in the system. Then, inconsistent edges are removed from the tree according to proposed criteria. This leads to the identification of the coherent groups of generators. Two algorithms are proposed for the elimination of the edges in the maximum spanning tree, both based on Fukuyama-Sugeno validity index. The method is tested on 68-bus test system and 678-bus Italian equivalent system. Results are compared with classical approaches.