33 Results for the search " AC":
Fault on a line
Description:
This model is a faulty line. The distance of the fault from the origin is a parameter. CP or PI models are used on each side of the fault according to the time step. If the time step is small enough t... see moreo simulate the propagation in the line with at least 10 time steps, CP is used, else it is PI.
Tutorial on exported mask (Demonstrated with an exciter)
Description:
In this example, a device is placed in a subcircuit. The goal is to be able to modify the parameters of this device from the parent mask.
However, this device is a masked subcircuit and therefore... see more ## are not accepted. Here are two options to achieve this task.
Tag(s): exported, mask, exciter, governor, subcircuit, subnetwork, script, method
Short-Term Scheduling of Active Distribution Systems
Description:
The latest distribution management systems tend to incorporate optimization functions for the short-term scheduling of the various energy and control resources available in the network (e.g., embedded... see more generators, reactive power compensators and transformers equipped with on-load tap changers). The short-term scheduling procedure adopted in the paper is composed by two stages: a day-ahead scheduler for the optimization of distributed resources production during the following day, an intra-day scheduler that every 15 minutes adjusts the scheduling in order to take into account the operation requirements and constraints of the distribution network. The intra-day scheduler solves a non-linear multi-objective optimization problem by iteratively applying a mixed-integer linear programming (MILP) algorithm. The linearization of the optimization function and the constraints is achieved by the use of sensitivity coefficients obtained from the results of a three phase power flow calculation. The paper shows the application of the proposed approach to a medium-voltage 120 buses network with 10 dispatchable generators and 2 transformers equipped with on-load tap changers.
Authors: A. Borghetti, M. Bosetti, S. Grillo, M. Paolone, F. Silvestro
IEEE Bucharest Power Tech Conference, June 28th - July 2nd, Bucharest, Romania
Tag(s): Distributed generation, operation of distribution networks, MILP.
Selection of MV/LV Transformers to be Protected by Surge Arresters against Indirect Lightning Overvoltages
Description:
The papers addresses the problem of locating surge protective devices in a medium voltage distribution network by means of an accurate computer model for the calculation of lightning induced overvolta... see moreges and a Monte Carlo statistical procedure. The indirect lightning performance of small network cells of different configuration are evaluated and used as a benchmark for the validation of the surge arrester locations provided by a genetic algorithm procedure. The obtained results appear useful for the lightning protection design of networks
with complex topology.
Authors: Alberto Borghetti, Fabio Napolitano, Carlo Alberto Nucci, Fabio Tossani, Gilnei J. G. Dos Santos, Donorvan R. Fagundes, Gustavo P. Lopes, Manuel L. B. Martinez
2014 International Conference on Lightning Protection (ICLP), Shanghai, China
Tag(s): distribution network; surge arresters; lightning protection.
Indirect-Lightning Performance of Overhead Distribution Networks With Complex Topology
Description:
The paper deals with the evaluation of the indirect-lightning performance of overhead distribution networks. The novelty of this contribution is that it takes into account the inherent complexity of d... see moreistribution networks. These networks are indeed characterized by a plurality of lines (main feeder and laterals) and also by the presence of typical power components (e.g., transformers and surge arresters); they consequently differ considerably from the straight line configuration generally adopted in this type of studies.
To accomplish such an evaluation we have extended the general procedure already presented in a previous paper based on the use of the LIOV code along with the Monte Carlo method. The extended procedure combines the advantage of the LIOV-EMTP computer code—that allows the calculation of lightning-induced voltages in complex distribution networks—with a heuristic technique specifically developed and integrated in the Monte Carlo routine in order to reduce the computational effort. The application of the proposed procedure to a set of distribution overhead networks characterized by different topologies, but all of the same length, shows that, in general, the usual single straight-line approach may result into a misestimation of the indirect-lightning performance. The paper also analyzes and discusses the influence of both the line terminations, and the position of the line poles.
Authors: Alberto Borghetti, Senior Member, IEEE, Carlo Alberto Nucci, Fellow, IEEE, and Mario Paolone, Member, IEEE
IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 24, NO. 4, OCTOBER 2009
Tag(s): LIOV-EMTP, lightning-induced overvoltages, lightning performance, power quality, distribution systems, overhead power lines.