Technical Presentations

Ground Fault Overvoltage with Inverter-Based Distributed Energy Resources841

Abstract
A Ground Fault Overvoltage (GFO) can occur in situations where an ungrounded transmission line and associated ungrounded transmission equipment is energized from distribution connected Distributed En... see moreergy Resource (DER) during a transmission single-phase-to-ground (SLG) fault. The condition could result in 1.73 pu overvoltage on phase to ground connected equipment which will be sustained until the DER ceases to energize the substation distribution transformer. Transmission equipment on the isolated circuit will be subjected to the above phase to ground overvoltage, also if there is frequency shift, the isolating transmission circuit breakers could potentially see up to 2.73 pu phase to ground overvoltage. Such an overvoltage can cause damage to customer or utility equipment and must be avoided. GFO concerns are already becoming a barrier to large-scale DER deployment either by posing low hosting capacity or by necessitating installation of costly mitigation equipment. Utilities need to study GFO risks and identify low-cost mitigation options to enable large-scale DER deployment. Given the fundamental differences in mechanisms and phenomena driving a GFO under DERs, classical GFO analysis methods do not apply to inverters, and advanced simulation methods and tools are required.


This presentation highlights EPRI’s work on GFO analysis, concerns, and evaluation of mitigation options using EMTP. The objective is to determine if or when high DER penetration presents a GFO problem and how to prioritize the mitigation and equipment evaluation. This includes evaluating the impact lightning arresters can have in reducing or clamping the overvoltage, the application and performance of high voltage substation overvoltage protection, and DER on-board voltage/frequency protection. The presentation further provides modeling recommendations for such a study using EMTP. As DER deployment increases, utilities will need to perform similar analysis to identify potential overvoltage risks and develop low-cost mitigation methods. This work provides a basis for such a study.

Tag(s): gfov, tov, ibr, DER, inverter, islanding, load rejection, inverter based resources

EMTP® studies for IBR integration at Hydro-Quebec777

Abstract
Abstract:

Hydro-Quebec has been involved in EMTP® development since the 80s and has collaborated with several organizations worldwide through the Development Coordination Group of EMTP (DC... see moreG-EMTP). Hydro-Quebec was the key player in the EMTP recoding project that allowed the delivery of the latest generation of the software in 2003. The new EMTP was developed at IREQ (Hydro-Quebec’s research center) from 1998 to 2003.

Hydro-Quebec was the first organization to simulate its complete transmission grid in EMTP. Hydro-Quebec was also the first system operator to require that manufacturers of wind turbines provide detailed EMT-type (EMTP®) models for wind park integration studies. This webinar will present:
• How EMTP simulations are integrated into Hydro-Quebec’s work process?
• How EMTP simulations can complete RMS simulations?
• Future simulation challenges

Speakers:
• Karine Gauthier, ing.
• Pascal Prud’homme, ing.
• Saad Omar, ing.

A new resource is available to explain step-by-step how to create a DLL in EMTP.776

Abstract
A new step-by-step resource is available to explain how to create a DLL in EMTP®.

The DLL (Dynamic Link Library) function is designed to allow EMTP® users to develop advanced program mode... see morel modules and interface them directly and intimately with the EMTP® engine. It is for advanced users and offers advanced capabilities.

Users interested in programming language-based model development should use this feature to develop and maintain models. Such models can be placed in a specified location, attached to a device with graphical user interface features in EMTPWorks and maintained in a library just as any other built-in EMTP model.

This option may be used by converter manufacturers to interface real code into EMTP®, to perform Software In the Loop.

For this purpose, EMTP® is also compatible with the Joint IEEE TASS Task Force and CIGRE B4.82 Working Group “USE OF REAL-CODE IN EMT MODELS FOR POWER SYSTEM ANALYSIS”.

Transient immunity assessment of wind and solar parks773

Abstract
Abstract
Inverter-base Resources (IBRs), such as solar photovoltaic (PV) and wind parks are subject to transients which may cause more issues as compare to traditional generation due to the colle... see morector grid and the geographical spread between converters. In this webinar, we present several challenges which may be faced by planners and park developers:
- Transient immunity against utility-owned capacitor bank switching. Assessment of IEEE Std 1547-2018.
- Ferroresonance after open-phase faults.
- Temporary overvoltage (TOV) in a PV parks after a phase-to-ground fault
Events and EMTP simulations will be described and analysed during the webinar.
This work was performed with the collaboration of Bob Arritt, EPRI and Chest Li, Hydro One

Presenters:
• Hossein Ashourian - Power System Modeling and Simulation Specialist

• Anton Stepanov - Research And Development Specialist

Performance of conventional sources vs Inverter based source during power system faults771

Abstract
This presentation will contract the performance of conventional power source to those of inverter based resources (IBR) and how this impacts the performance of traditional protection devices.