Performance indices are used to rank the impact of contingencies in power system security studies. In this paper it is proposed a new approach to the use of performance indices to contingencies screening. The developed methodology produces a screening and classification of the system outages. The developed technique is applied to a test power system and the results obtained were analyzed. Finally, some conclusions that provide a valuable contribution to the understanding of the power system security analysis are pointed out

This paper proposes a simple case study to demonstrate the impact of different interior lighting solutions on energy efficiency. As an example, the students will be proposed to use dedicated software DIALux 4.9, and will learn how to develop a lighting design project. Students will be asked to perform a cost-efficiency analysis in order to evaluate the different selected options. At the end of the case study, students will learn and draw some important conclusions that provide a valuable contribution to the understanding of the lighting design in general.

This paper presents a transient stability preventive control technique based on a hybrid method. In order to maintain the power system security it is evaluated the generators output power that should be shift from the most unstable synchronous machines to the undisturbed units. The reallocation of the generators output power is carried out using an optimal power flow program. The hybrid method is a very important tool for the transient stability analysis, since it allows a fast evaluation of the stability limits and margins. This approach can also easily accommodate detailed models of the network devices and protective schemes. In order to validate the established mathematical models it was studied the transient stability of the New England test power network. The results obtained with the proposed methodology were compared with the solutions produced by another numerical formulation, showing a very close agreement.

For domestic consumers, electricity tariffs usually have two components: one is related to the maximum available current/total power (billed in €/day) and the other concerns to the energy consumption (€/kWh). The main switchboard current is usually limited, according to the contracted power level, by way of automatic switches. To avoid main switchboard tripping by current limit violation, Electric Vehicle (EV) owners may decide to increase their contracted power (and the energy bill) or to adopt charging strategies that limit the global consumption (EV plus house needs) to the contracted current/power. In this paper, an Intelligent Electric Vehicle Charging Controller (IEVCC), allowing to use the contracted power to the maximum extent, is presented. A set of user configurable parameters can be used to define the controller behavior, in order to prevent a full switch-off. Two versions are described: a single user version that can be used at private houses and a mesh version that can be used in multi apartment buildings, providing information about consumed energy, time of use, costs and past bills.

This paper describes an educational case study approach to FACTS controllers on an electric power network. Application software, SIMFACTS, was developed by the authors with the GUIDE tool from Matlabtrade in order to simulate the power system effects resulting from the inclusion of FACTS controllers. The studied topologies were: series, shunt and combined compensators. A simple explanation of several controllers, mainly STATCOM, SVC, TCSC, SSSC and UPFC is made in order to understand the singular concepts behind FACTS technology. A case study showing the main results regarding the impact of FACTS controllers on a steady-state operation of a test power network is presented. It is also included an example of the power flow solutions using one of SSSC controller. A sudden bus load change with a coupled STATCOM controller is also presented.