1,721,047 research outputs found
Research activities on techniques to analyse harmonic distortion due to modern AC rails and investigation of X/R ratio of realistic 25 kV Equipment
No full textAllocation of Capacitors and Voltage Regulators in Unbalanced Distribution Systems: A Multi-objective Problem in Probabilistic Frameworks
No full textPlanning of distributed energy storage systems in μgrids accounting for voltage dips
No full textThis paper deals with the optimal planning of the electrical energy storage systems in the microgrids aimed at cost minimization. The optimization accounts for the compensation of the voltage dips performed by the energy storage systems. A multi-step procedure, at the first step, identifies a set of candidate buses where the installation of a storage device produces the maximum benefit in terms of dip compensation; then, the life cycle costs in correspondence of different alternatives in terms of size and location of the storage systems are evaluated by considering an optimized use of the energy storage systems. The simulations on a medium voltage microgrid allowed validating the effectiveness of the proposed procedure
Tools for Assessing the Robustness of Electrical System against Voltage Dips in terms of Amplitude, Duration and Frequency
No full textOptimal Siting and Sizing of Electrical Energy Storages Accounting for Voltage Dip Economic Regulation
No full textStarting from the novel evaluation given in the recent Italian regulation to voltage dip costs, this paper focuses on distribution level and proposes to face voltage quality problems through the use of electrical energy storage systems which are supposed to provide voltage compensation in a medium voltage microgrid. The storage systems are assumed to be employed also for the reduction of the cost of energy sustained by the microgrid operator. A siting and sizing methodology of the electrical energy storage systems is proposed. For the economical evaluation, probabilistic distributions are used for some of the inputs of the procedure. Eventually, a sensitivity analysis is proposed aimed at analyzing the effects of different values of the penalties given for voltage dips
New challenges for forecasting voltage sags due to lightning phenomena in distribution networks
No full textVoltage sags cause severe problems in distribution systems, resulting in huge economic losses; they may occur due to overvoltages and short circuits caused by lightning phenomena. The proposed research aims at developing a tool to forecast, with an adequate lead time, the main characteristics of the voltage sags caused by lightning phenomena in active distribution networks. The development of the tool requires methods for supporting decisions under uncertainty, the short-term forecasting of lightning affecting distribution systems and the modeling of: i) the lightning overvoltages and flashovers on overhead lines; ii) the line insulation withstanding characteristics to lightning overvoltages; iii) the impact of distributed generation contribution in short-circuit operating conditions; and iv) the voltage sags characteristics. All tasks are considered and described in this paper
A probabilistic approach for optimal capacitor placement in a distribution system using simultaneous perturbation stochastic approximation
No full text
Planning of energy storage systems in unbalanced microgrids
No full textThis paper proposes a planning technique aimed at optimally sizing and locating distributed storage devices in an unbalanced low voltage microgrid. The planning procedure is formulated in terms of a mixed, non linear, constrained optimization problem: the objective function to be minimized is the cost sustained for the energy provision and for the inclusion of the storage resources while the equality/inequality constraints guarantee the correct operation of the components and of the grid. The problem of unbalances is also dealt with by imposing a maximum unbalance factor value to all of the grid busbars' voltage. The results of numerical applications are shown to validate the proposal
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