Abstract
This paper describes a practical instrument for realtime visualization of the necessary quantities for analysis, diagnosis and investigations of AC machine drives on an oscillographic display. The instrument needs no shaft position or speed sensor, it uses exclusively the acquired stator currents and voltages and provides information, in electrical and visual form, of: starer and rotor flux, torque, reactive power, torque current, flux current, torque angle and slip frequency. In the present version, the instrument circuitry is based on analogue signal processing techniques. The theoretical basis is a continuous-time machine model defined by a pair of simultaneous complex-coefficient differential equations. A formalization of the various calculation methods for the signal estimation is presented as well as one interpretative computer simulation for the stator current pattern. Practical results obtained with the device when applied to test and measure a real motor drive are presented and some conclusions are drawn. Main fields of application of the calculator include: monitoring systems, control units, research tools for induction motor drives, and test shops.

Abstract
This paper proposes a design of a sliding mode controller for direct torque control of an induction motor drive. The design includes the hardware structure, the control laws for torque control and rotor flux control. The modulation is defined as part of the variable structure control algorithm which enables an optimum choice of output voltage of the static converter. The validity and robustness of the proposed control system were verified by simulation. The simulation results are presented to demonstrate their agreement with theoretical predictions of the proposed controller. Copyright (C) 1998 IFAC.

Abstract
This paper shows the conceptual differences between adopting a probabilistic weighting of the futures and a risk averse strategy, in power system planning under uncertain scenarios. It is illustrated with a distribution planning problem, where optimal solutions in both cases are determined by a Genetic Algorithm. It shows that the probabilistic approach is less safe and cannot detect some interesting solutions.

Abstract
This paper demonstrates that a classical stochastic optimization is, in many cases, not convenient for power system planning. Instead, a risk analysis approach is proposed. In a comparison of both planning paradigms, the probabilistic approach is in occasions not adequate, is half blind to compromise solutions and leads, in numerous, cases to riskier decisions. The technical discussion is illustrated with a distribution planning example.

Abstract
This paper provides an overview and a list of references on the use of Evolutionary Algorithms (EA) in Power Systems and related fields. As didactic examples, the paper presents two applications of EA for two different problems in Power Systems. (C) 1997 Elsevier Science Ltd.

Abstract
This paper presents a methodology developed within the SOLARGIS project - a Joule project - aiming at evaluating the potential of integrating renewable forms of energy for dispersed electricity production. With this project we also wanted to demonstrate the efficiency of GIS - Geographical Information Systems - as a tool to analyse the integration of renewable forms of energy. In this paper we present the methodologies developed to identify renewable resources in a given geographic region, to detect high potential areas for wind farm siting and to evaluate the efficiency and market of isolated systems to be used for dispersed rural electrification. In this last methodology we used fuzzy models to describe the uncertainties in demand and cost values.