Abstract
The software package TRANsySTEM developed for teaching and research purposes of the transient security assessment of a multimachine power system is presented. This package run in Windows environment.

Abstract
An online recursive algorithm for power system state estimation is presented which is based on the use of the Kalman filtering theory. The recursive form of the algorithm is advantageous in two ways: it permits the inversion of smaller-dimensioned matrices, which results in simpler algorithms, and it provides the opportunity to obtain a partially updated estimate in case the computer is heavily loaded in a given period and there is not enough time to perform a single batch processing of the measurement vector as a whole.

Abstract
M. T. Valdez, C. F. Agreira, C. M. Ferreira, F. P. Maciel Barbosa. Teaching, Learning and Exploring the Use of Project-Based Learning // Electronics and Electrical Engineering. - Kaunas: Technologija, 2010. - No. 9(105). - P. 117-120. Education in academic institutions of higher education is not an easy task, with engineering students needing to be competent in the contents areas as well as in a generic way. This paper describes the implementation of a strategy of the PBL model applied to design a curriculum unit of Electric Power Systems Project (EPSP) of the Electrical Engineering course. This curriculum unit aims to provide students with knowledge to design, model, analyze, and project interior and exterior lighting systems. The results show that students have really benefited from the experience of actually working as members of a team rather than learning using conventional classes. III. 4, bibl. 23 (in English; abstracts in English and Lithuanian).

Abstract
The proper analysis and successful operation of a power system implies a reliable estimate of its state. As a result the State Estimation (SE) is nowadays considered as the heart of the modern control centers. Several dynamic state estimation algorithms based on the extended Kalman filtering theory (EKF) have been proposed in the literature but as it has been reported numerical problems may arise in its implementation in practice. To circumvent the problems inherent to the Kalman filter algorithm we present in this paper an algorithm for power system state estimation based in the square root filtering technique. The estimator proposed is decoupled in nature due to modifications made in the measurement equations resulting in a new observation model.

Abstract
In this paper it is presented an on-line dynamic hybrid transient stability formulation. This efficient and robust approach combines both a time domain integration method to compute the initial system trajectory with the extended equal area criteria to obtain the transient stability margins and the critical clearing times. The computer programs developed by the authors were applied to a multimachine power network. The results obtained with this hybrid formulation were compared with the solutions produced by a direct approch and by the Runge-Kutta method. Finally, some conclusions that provide a valuable contribution to the understanding of the multimachine power system preventive control are pointed out.

Abstract
Nowadays, the large penetration of wind power generation poses new challenges for the dynamic voltage stability analysis of an electric power system. In this paper is studied the influence of the reactive power management for wind power plants in the dynamic voltage stability of an electric power network under a fault condition, considering two different Doubly-Fed Induction Generators (DFIG) models. The simulation results were obtained using the EUROSTAG software package.