Exchange Platform

Author: e.malaval
Type: Model
Downloaded: 73 times
Date: 2022-01-19

HVDC models

Description:
These models contain a 3-phase rectifier (AC/DC) and a 3-phase inverter (DC/AC).

The average model (AM) just contains a control circuit that is connected to several controlled sources.
... see more
The detailled model (DML) contains complete inverter and rectifier models and represents the semi-conductors.

Tag(s): Power electronics, inverter, rectifier, average, detailled

Author: n.sene
Type: Publication
Date: 2015-04-02

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.

Author: n.sene
Type: Publication
Date: 2015-04-01

DISPERSED ENERGY RESOURCES SCHEDULING FOR THE INTENTIONAL ISLANDING OPERATION OF DISTRIBUTION SYSTEMS

Description:
The paper presents an algorithm for the automatic optimal scheduling of dispersed energy resources (DERs) and of under-load tap changers (ULTCs) position. The aim of the scheduling problem consists in... see more the minimization of the voltage deviations with respect the rated value, of the DERs production deviation with respect the maximum efficiency point, and of the network losses.
The system incorporates also a procedure to facilitate the intentional islanding maneuver of the distribution network. The adopted approach is based on iterative solution of linear-constrained multi-objective optimization problems. The nonlinear power flow relationships are linearized by means of the calculation of sensitivity coefficients to small variations of the control variables (namely, controllable DERs power outputs and ULTCs positions). The algorithm is implemented in Matlab environment to exploit different solvers and suitably interfaced with EMTP-RV for three-phase power flow detailed calculations. In particular, two optimization solvers are adopted: the least square method and the goal attainment approach. The relevant results are compared using the IEEE 34-node distribution feeder as test case.

Authors: A. Borghetti, C.A. Nucci, M. Paolone, M. Bosetti

Tag(s): Dispersed generation, active distribution networks, islanding operation.

Author: n.sene
Type: Publication
Date: 2015-04-01

Transient recovery voltages in vacuum circuit breakers generated by the early-interruption of the inrush current of large motors

Description:
The switching of medium voltage electrical motors is typically realized by means of vacuum circuit breakers (VCBs) essentially in view of their elevated number of switching cycles. As known, switching... see more of VCBs generates important transient recovery voltages (TRVs)
that need to be properly evaluated in both VCB sizing and in the power system insulation coordination. As large medium voltage electrical motors are installed into plants typically controlled by means of Supervisory Control And Data Acquisition (SCADA) systems,
maneuvers that involve the motor inrush followed by its sudden de-energization (due, in general, to the intervention of an automatic diagnostic function), resulting into important TRVs, are not unusual. The paper aims at investigating the TRVs due to this specific type of
VCB switching by means of a model implemented in the EMTP-RV simulation environment. By making reference to a real plant, the validation of the implemented models is obtained by comparing the simulation results with some experimental transients provided by the plant data fault recorder. The paper finally discusses the adequacy of different countermeasures by analyzing their effectiveness for the TRVs limitation.

Authors: A. Borghetti, F. Napolitano, C.A. Nucci, M. Paolone, M. Sultan, N. Tripaldi

CIGRE - International Symposium “Assessing and Improving Power System Security, Reliability and Performance in Light of Changing Energy Sources” Recife, Pernambuco, Brazil, April 3-6, 2011
Topic 3 – System technical performance
Subtopic 3.5 – Switching and lightning transient on power systems. Impact on performance and measurements

Tag(s): Transient recovery voltages, vacuum circuit breakers, motor inrush currents, EMTP simulations

Author: n.sene
Type: Publication
Date: 2015-04-01

A PROCEDURE FOR THE AUTOMATIC SCHEDULING OF DISTRIBUTED ENERGY RESOURCES IN MEDIUM VOLTAGE NETWORKS

Description:
The paper presents the main characteristics of a centralized two-stage scheduler designed for the integration in the Distribution Management System (DMS) under development in the framework of an Itali... see morean “Smart Grid” Project. The paper first reviews the trends in the automation of power distribution networks, and then describes the two-stage scheduler and its application to typical Italian urban and rural distribution feeders.

Authors: Alberto BORGHETTI, Mauro BOSETTI, Carlo Alberto NUCCI, Mario PAOLONE, Stefano MASSUCCO, Federico SILVESTRO and Sandra SCALARI

C I R E D - 20th International Conference on Electricity Distribution Prague, 8-11 June 2009

Tag(s): Distribution Management System, Smart Grid, automation