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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: admin2012
Type: Document
Downloaded: 194 times
Date: 2014-06-02

Co-simulation Platform for the Analysis of Communication-based

Description:
The paper presents an ICT and power co-simulation platform for the analysis of the volt/var control and relevant optimization in medium voltage distribution feeders, achieved by means of a system of d... see moreistributed controllers coordinated via a shared band-limited digital communication network. The platform has been built by realizing the interface between two specific simulation environments: the Electromagnetic Transient Program EMTP-RV and the communication network simulator Opnet Modeller. The preliminary results provide basic indications on the expected performances of the considered communication-based strategies for different traffic congestion levels and load/generation dynamic variations.

Tag(s): Co-simulation, Networked Control Systems, Power distribution feeders, Volt/var optimization

Author: e.rutovic
Type: Library
Downloaded: 456 times
Date: 2013-02-26

Control Devices of TACS

Description:
An EMTP-RV TACS (Transient Analysis Control Systems Library) containing :
- TACS 50 : Frequency meter
- TACS 51 : Relay
- TACS 52 : Level-Switch
- TACS 53 : Delay
- TACS 54 :... see more Pulse delay
- TACS 55 : Digitizer
- TACS 56 : X-Y point list
- TACS 57 : Sequenced switch
- TACS 58: Integrator
- TACS 59 : Derivator
- TACS 60 : Input Selector
- TACS 61 : Input Selector
- TACS 62 : Sample and Track
- TACS 63 : Instantaneous Max/Min
- TACS 64 : Max tracking
- TACS 65 : Accumulator
- TACS 66 : RMS Meter

Tag(s): TACS

Author: gerinlajoie.luc
Type: Model
Downloaded: 464 times
Date: 2012-11-23

Extra control of machines - IEEE AVR

Description:
The proposed AVR sub-circuit models consist of a few IEEE 421 standard exciter[1] and Power Systems Stabilizer and governor. Don't forget to click the require observed signals in the SM devi... see morece, see Observe and Mechanical Tabs (vd, vq, if, Pmss, Efss, Omega_1, etc.) In this file, many duos and trios combinations of:
Exciter:
- IEEEX1 (dc1),
- IEEEX2,
- IEEEX4,
- IEEET5,
- EXST1,
- EXST1A,
Stabilizer:
- PSS1A,
- PSS2B,
- PSS4B,
- Q type II (var control)
Governor:
- IEEEG0,
- IEEEG1,
- IEEEG3,
- DEGOV1
- GAST,
- TGOV1,
- TGOV5[1]
IEEE Std 421.5, Recommended Practice for Excitation System Models For Power System Stability Studies, 2005

Tag(s): Components

Author: gerinlajoie.luc
Type: Model
Downloaded: 246 times
Date: 2012-11-23

Extra control functions

Description:
Extra control functions, 17 components: Dead band, Friction, QuantizerLess than (for T1 duration and reset at 110% of the level)
- useful for analogical inputLess than (for T1 duration and reset... see more after T2 duration when higher the level)
- useful for numeric inputGreater than (for T1 duration and reset at 90% of the level)
- useful for analogical inputGreater than (for T1 duration and reset after T2 duration when lower the level)
- useful for numeric inputInverse
- time (5points), external resetFrequency meter, with 4 outputs: rate(Hz/s), period(s), deltaF (pu) and F (hz); based on phase C measurementPI with variables low and hi limitsPI with variables Kp and Ki, low and hi limitsLim(du/dt) , rising and falling fixed, Lim(du/dt) , rising and falling variableFour second order filters,

Tag(s): Components