Abstract

Abstract

Abstract
The allocation of the system losses to suppliers and consumers is a challenging issue for the restructured electricity business. Meaningful loss allocation techniques have to be adopted to set up appropriate economic penalties or rewards. The allocation factors should depend on size, location, and time evolution of the resources connected to the system. In the presence of distributed generation, the variety of the power flows in distribution systems calls for adopting mechanisms able to discriminate among the contributions that increase or reduce the total losses. Some loss allocation techniques already developed in the literature have shown consistent behavior. However, their application requires computing a set of additional quantities with respect to those provided by the distribution system power flow solved with the backward/forward sweep approach. This paper presents a new circuit-based loss allocation technique, based on the decomposition of the branch currents, specifically developed for radial distribution systems with distributed generation. The proposed technique is simple and effective and is only based on the information provided by the network data and by the power flow solution. Examples of application are shown to confirm its effectiveness.

Abstract
In this paper, a new traffic separation mechanism is proposed for IEEE 802.11e networks. Such Traffic Separation Mechanism (TSm) allows the coexistence of CSMA standard stations with modified (real-time) stations in the same network domain. A station implementing the proposed TSm scheme has the same operating behavior as a standard IEEE 802.11e network station, except in what concerns the evaluation of the backoff delay. For the case of stations implementing the TSm scheme, whenever they have traffic to transfer, they eventually impose its transfer prior to the transfer of any other message with lower priority. This behavior guarantees the highest transmitting probability to the TSm stations in an open communication environment, where multiple IEEE 802.11e standard stations may coexist with a subset of TSm-enabled real-time stations.

Abstract
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.

Abstract