Abstract
This paper proposes an integrated approach of genetic algorithms, Tabu search and simulated annealing for multi-stage (dynamic) transmission network expansion planning. The proposed algorithm integrates the most interesting and best features of the above individual algorithms. The efficiency and reliability of the proposed algorithm is proved with the modified Garver's six-bus network. Finally, a real-world application (Sri Lankan transmission network) of the integrated algorithm is presented for multi-stage transmission expansion planning.

Abstract
This paper reports the building of a system for predicting load curves at Low Voltage Substations supplying a set of consumers of different types (residential, industrial, etc.). The system is built by the aggregation of individual Fuzzy Inference Systems of the Takagi-Sugeno type. The paper describes how actual measurements formed a base of raw data and how test and training sets could be built from this base. Results produced by the prediction system and their comparison with actual load curves confirm the good performance of the model.

Abstract
In this paper we present a complete methodology to perform state estimation studies in distribution networks. Due to the peculiarities of these networks the traditional state estimation concept was enlarged in different ways. It includes a load allocation study, as a way to cope with the reduced number of real time measurements in SCADA database. The algorithm estimates binary values of topology variables, due to incomplete or erroneous topology information in the control center and it is able to include data modeled by fuzzy numbers as a way to include fuzzy results of the load allocation procedure or fuzzy assessments from experts. Finally, the paper describes a methodology developed to tune the weights to be used in the state estimation based on a Takagi-Sugeno fuzzy inference system. The paper includes a case study based in the IEEE 24 bus system to highlight and illustrate its application in a variety of situations.

Abstract
This paper presents a method used to validate a spatial load forecasting model based on fuzzy systems implemented in a Geographical Information System. The validation process confirms the adequacy of the rule base, and also it is strictly necessary to define the confidence intervals associated to the predicted spatial demand.

Abstract
One of the important decision problems for a power system operator is to choose the appropriate operation point when possible contingencies must be considered. The operator may decide to do nothing or to take some actions that change the operating point and decrease the negative impact (cost) of some or all the contingencies. The purpose of this paper is to investigate the applicability of utility and value functions to this decision problem, since the large range of consequences raises some doubts about the fulfillment of the theoretical conditions imposed by Decision Theory. Although not essential to this discussion, some alternatives to prescriptive methodologies are presented and discussed, mostly regarding the definition of risk attributes and other determinist equivalents, suitable for multicriteria analysis.

Abstract
This paper addresses the allocation of electrical losses in distribution networks with embedded generation, in a liberalized environment. The nonlinear nature of the issue, the loss changes due to voltage variation and, specially, the contribution of embedded generation to loss variation are considered. The proposed method is based on tracing the real and imaginary parts of the currents and has two steps. First, the losses in the distribution network, in the absence of embedded generation, are allocated to the consumers (or their providers). Second, the variations in the losses that result from the influence of embedded generation are allocated to the generatorsi These variations are a measure of the avoided or added costs related to losses. In the allocation process, made in a branch basis, both real and reactive powers are considered. The methodology presented in this paper can be used to evaluate embedded generation incentives or to design tariffs for the use of the distribution network.