Abstract
In this paper one proposes that the concept of risk should be central in a distribution planning methodology, and that the procedures and models adopted should be used to take that factor in account and assess the robustness and exposure of the solution studied. It is also argued that this purpose is best served if a multicriteria approached is adopt as much as possible, keeping explicit record of the values of the serval attributes that may classify the goodness of a solution.

Abstract
In this paper, system component reinforcements are analyzed from the perspective of their impact in increasing flexibility in system design. The proposed framework integrates a fuzzy optimal power flow model through which one can derive, as a function of load uncertainties, possibility distributions for generation, power flows and power not supplied. Exposure and robustness indices, based on risk analysis concepts, are defined. These indices can be used to rank the expansion alternatives, giving the planner insight to system behavior in face of adverse futures. Their use in conjunction with investment assessments is proposed as a necessary step in a decision making methodology.

Abstract
Fuzzy modelling of power systems is proposed, to take in account the qualitative aspects and vagueness or uncertainty that have not, in fact, a random nature and therefore cannot be modelled by a probabilistic approach. An operative procedure to derive fuzzy load diagrams associated with different types of energy consumption is presented. The feasibility of the development of fuzzy linear programming models for power system planning is demonstrated. A DC and an AC fuzzy load flow formulations are developed and the quality and usefulness of the results obtained with them is made evident with the help of an example.

Abstract
The basic function of an electric power system is to satisfy the customer energy requirements as economically as possible and at an adequate level of continuity and quality. Reliability calculations such as those described in this paper can be used with advantage in establishing additional security constraints, that if used in the right context and backed up by the inevitable economic analysis, provide better and more consistent information for system planning or expansion studies. The model described can also be used when the simulation of the actual operating conditions is necessary.

Abstract

Abstract