Technical Presentations

Analysis of transient recovery voltage on circuit-breaker connected to HV terminals of step-up transformer located in hydro power plant 871

Abstract
This presentation deals with TRV on circuit-breaker installed in GIS at HV terminals of step-up transformer located in hydro power plant. An overview of standards covering TRV will be given. Modelling... see more of power system components in EMTP® for TRV studies will be shown (generator, power transformer, electric arc model inside circuit breaker, etc.). Results of EMTP® simulations will be presented covering different cases of TRV (for out-of-phase conditions, single-phase to ground and three-phase faults, short-line faults, switching off small capacitive currents, etc.).

Tag(s): Transient Recovery Voltage (TRV), Step-Up Transformer, Generator Synchronization, Out-of-Phase Switching, Short-Circuit

Switching of Inductive Currents and Dimensioning of RC-Snubbers with PAMSUITE846

Abstract
In order to control the voltage in distribution and transmission networks shunt reactors can be used for compensation of reactive power. Due to the switching of their inductive currents, unacceptable ... see moreswitching transient voltages might occur which can lead to damage of equipment. Furthermore, the breaker must be able to withstand the transient recovery voltage (TRV), amplitude and rate of rise (RRRV) respectively. One possibility to mitigate these switching transients are so-called RC Snubbers. They have to be dimensioned according to the topology and the values of R and C can be optimized with the PAMSUITE tool. In this presentation the modelling and the results of the TRV due to shunt reactor switching is discussed and the mitigation with RC Snubbers with the help of PAMSUITE is shown.

Tag(s): TRV, PAMSUITE, snubber, switching

Analysis and Calculations in Medium Voltage Electrical Systems833

Abstract
The electrical installation of an industrial site is a complex structure. Analyzing behavior in a transient condition allows optimum selection of the operation and protection devices in the installati... see moreon design phase; in addition, possible weaknesses and critical points can be highlighted in advance, allowing prevention of potential problems, damage to machinery, and costly periods of down time.

In order to completely satisfy the needs and expectations of the customer, in ABB Electrification Business an important role is played by analyses and consulting services offered by Field Application Support (FAS) specialist.

In this session of the "EMTP User conference", representatives from the Italian ABB Distribution Solution division, based in Dalmine (BG), will show how EMTP tool supports the analyses performed within the "Medium Voltage Circuit Breaker Suitability" reports that are provided to customers looking for switching devices for special applications. In particular, the today presentation will focus on "CB suitability" study approach for the Generator Circuit Breaker and the Filter Harmonics switching applications

Tag(s): TRV, generator breaker, filter, switching

POWERGRID experience with EMTP793

Abstract
To meet the increasing power demand, a number of extra high voltage (EHV) transmission lines is being added to the power system network, which enhances the complexity of power system network. It is es... see moresential duty of power engineer to fulfill the growing demand ensuring the reliability, stability & security of GRID. Transient simulation tools like EMTP play a vital role to provide the flexibility to power engineer for simulating/studying the various case scenarios which couldn’t be simulate in physical power system.


Such tools eventually help power engineer to build a sustainable and secure GRID. In POWERGRID, being a central transmission utility, various studies are being carried out to arrive the technical particular of new transmission system and optimize or fine tuning of existing system. Some of them i.e. Transient Recovery Voltage (TRV) study of 1200kV Transmission network, Smart Power from insulated earth wire of EHV transmission line and 1200kV Transformer Inrush current study are discussed in presentation. 1200kV National Test Station was established & successfully charged along with the transmission line in state of BINA in India.


TRV study was carried out for assessment of various test duties of 1200kV Circuit Breaker. Presentation cover the detailed discussion of 1200kV TRV study and a brief about the facilities like HIL, HVDC control Replica setup, STATCOM replica setup available at Powergrid Advanced Research and Technology Centre (PARTeC).

Modeling and evaluation of overvoltage792

Abstract
A case study will be presented demonstrating modeling of overvoltage in a moderately sized system involving medium voltage vacuum breakers, cables and transformers. The focus is on simulating high fre... see morequency overvoltage generated by circuit breaker prestrikes and re-ignitions and evaluating the impacts on transformer insulation.
-Results obtained from a customized breaker TRV model which is capable of controlling the capability of switching high frequency current will be presented.
-The methodology of analyzing severity of overvoltage in the frequency domain was applied in this project. Results and discussions regarding frequency domain analysis will be shared.
-Simulation results regarding typical system configurations with variation of key parameters such as cable lengths, load power factors will be briefly presented.
-Application of EMTP study results in assisting equipment specification, as well as overvoltage mitigation methods including optimizing switching sequences, necessity of snubber circuits will be discussed.
-Case specific strategies to improve simulation speed and work flow with EMTP will be introduced and discussed.