Technical Presentations

EMTP Development Roadmap: Real-code DLL Interface828

Abstract
Real-code models/DLLs
- Exact copy of a real control implementation
- Original source code of a controler


Why use real-code DLLs in EMT simulations?
- Ultimate accurac... see morey (same code as onsite)
- Manufacturer's intellectual property is protected


Applications:
- Modeling of windfarms, PV farms, HVDC, exciters, etc.

Tag(s): DLL Interface, control implementation, EMT simulations

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.

On a New Approach of Detailed Load Modeling in EMTP787

Abstract
A detailed load model based on component-based methodology is presented. Various Residential-commercial-industrial components such as VFD, LED, CFL, SMPS and other essential elements are developed. An... see more event in Brossard substation is reproduced for validation purposes.

Insulation Coordination Study of 765kV GIS SUBSTATION788

Abstract
Gas Insulated Substations provide cost effective solution due to reduced land requirements particularly in metropolitan area where power demand is registering steep growth. With the use of GIS technol... see moreogy, it is required to assess the risk of failure due to overvoltage. The Insulation Coordination study forms a very important aspect in design stage. This presentation deals with the IC study carried out for a large – 765/400/220kV GIS substation in a SUPER THERMAL POWER STATION in UTTAR PRADESH.


Due to the decreasing ratio of lightning impulse withstand voltage to the system voltage, the difference between LIOV and VFTO decreases and this factor calls for VFTO performance analysis for 765kV GIS as well.
The discussion includes modeling of Extra High Voltage GIS, Temporary Overvoltage (TOV), Lightning Impulse Overvoltage (LIOV), Switching Overvoltage (SOV) and Very fast transient Overvoltage (VFTO) performance analysis on 765kV GIS substation.
TOV typically caused by fault to ground, load rejections and energization of long lines are analyzed to decide the rating of the surge arrester.
LIOV simulation studies are carried out for possible onerous paths including longer and short paths to decide the location of the arrester. SOV analysis deals with the overvoltage due to switching operations during line energization, re-energization and fault occurrence and clearance.


The LIOV and SOV results have been validated with reference to protective levels prescribed. The VFTO analysis is performed with various GIS disconnector operations in accordance with the methodology and guidelines as per CIGRE WG D1.03-TB 519 and the results are validated with the limits specified.
Keywords: Insulation Coordination, VFTO, EHV, GIS, 765kV, Protective ratio.

Modeling of energy systems with renewable energy sources779

Abstract
The webinar presents a module for modeling renewable energy sources (Renewable Energy Systems) The module contains detailed models of wind and solar power plants and is successfully used to analyze va... see morerious types of steady state and transient processes: flux distribution, under- and over-voltage operation, switching overvoltages, subsynchronous oscillations, etc