Technical Presentations

Author(s): Bozidar Filipovic,Nina Stipetic, Franjo Vukovic
Type:PDF Presentation
Downloaded: 5
Date: 2022-09-01

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

Author(s): Domagoj Har
Type:PDF Presentation
Downloaded: 3
Date: 2022-09-01

Secondary arc in hybrid AC DC overhead lines872

Abstract
This presentation covers a specific issue related to hybrid AC / DC overhead transmission lines: the extinction of the secondary arc current of a faulted DC pole. As a result of a pole-to-ground fault... see more, breaker openings interrupt the short-circuit current. Because of the inductive and capacitive coupling between the AC circuit and the faulted pole, a small AC current (a few 10ths Amps) keeps flowing in the fault. This current is known as the secondary arc current and it may disappear after some time.

Tag(s): AC/DC Lines, Secondary Arc, Sensitivity Analysis, Frequency Scan, Shunt Reactors, High-Speed Earthing Switches

Author(s): Dr. Adhishree
Type:Technical Presentation
Downloaded: 4
Date: 2022-09-01

Data driven and machine learning based approach for microgrid protection using EMTP873

Abstract
Modern intelligent digital relays embedded with phasor measurement units have facilitated easy access and collection of electrical signals in a microgrid. ? In this work, a model for detection, locati... see moreon and isolation of faults in AC microgrids is presented. The real time voltage, frequency and current data are processed via simple formulations to detect the fault. The tripping command is promptly communicated to the incumbent line relays within fault tolerance time, after fault detection. The proposed scheme assures reliable protection in grid connected and islanded mode of operation with added security in case of primary protection failure. Post tripping, the exact location of fault in any distribution line from the utility grid is predicted using a fault locator module. This module is designed and developed by gaussian process regression technique. Further, various machine learning techniques used for fault location has been explored and compared to establish the superiority of GPR method over others. Also the features extracted for model training is quite simpler, which imposes less computational burden on central protection computer. An IEEE 15 bus distribution system with synchronous and solar photovoltaic based DG is simulated in EMTP platform to generate the electrical data. Further the required calculations are performed in MATLAB 2020a.

Tag(s): Machine Learning, Protection Schemes, Fault Detection, Fault Isolation, Real-Time Implementation

Author(s): Neerajchandra Patel
Type:Technical Presentation
Downloaded: 8
Date: 2022-09-01

Ferroresonance Phenomena for Voltage Transformer failure – Simulation & Analysis using EMTP and Mitigation Technique874

Abstract
Ferroresonance is an oscillating phenomenon between a non-linear inductance and a capacitor that can results in highly distorted over voltages and overcurrent. Ferroresonance phenomenon occurs when a ... see moreferromagnetic core inside an electrical device – primarily a voltage transformer or an unloaded power transformer – operates in the saturated condition, under which inductance has become a non-linear element. In practice, ferro resonance can be triggered even by a temporary introduction of core into saturation, e.g. resulting from switching operations or a change in voltage resulting from an earth fault.

Tag(s): Ferroresonance, Transformers, Low-Frequency Transients, Overvoltage, Non-Linear Element

Author(s): Jegadeesh Kumar
Type:Technical Presentation
Downloaded: 12
Date: 2022-09-01

Insulation coordination study of 220 kV transmission line for reliability improvement against lightning-induced overvoltages877

Abstract
This presentation shows a detailed insulation coordination verification using EMTP. It includes an accurate representation of transmission line components considering actual site data such as conducto... see morer arrangement, line length, line parameters, insulator details, tower structure and location, tower grounding resistance, and lightning data.

Tag(s): Insulation Coordination, Lightning Strike, LIOV, Line Surge Arresters, Back-Flashover