Technical Presentations

Slideshow of the projects from our grand prize winners857

Abstract
During this webinar, our two winners of the EMTP® Research Contribution Prize Program 2021 will present their work. The aim of the award is to recognize student contributions to the technology associ... see moreated with power system transients. The two competition categories are:
- Best accepted IEEE, IET, PSCC, EPSR or IPST journal or conference paper on EMT simulations;
- Best EMTP® model developed.

Discover our winner and the topics of their presentation:

o Husam Samkari, Ph.D. and P.E. in Electrical Engineering
Impact of Distributed Inverter-Based Resources on Incremental Quantities-Based Protection

Abstract:
This paper studies the impact of distributed inverter-based resources (IBR) on time-domain incremental quantities-based relays. One implementation of the incremental quantities for protection is a high-speed sub-cycle directional element. The incremental, also known as superimposed, quantities are fault-generated instantaneous components of voltages and currents. The directional element indicates fault direction based on the transient voltages and currents’ relative polarities. It is essential to ensure that the element does not fail to indicate the correct direction if IBRs fault current responses impact the quantities. IBRs’ fast control response impacts the current quantities by changing both magnitude and angle.

This paper characterizes the incremental quantities-based relay response to IBRs’ nonlinear fault currents. A modified IEEE 34-bus distribution with an IBR system is modeled and simulated using the electromagnetic transients program (EMTP) for demonstration.

o Rafael Castillo Sierra, Electrical Engineer, Ph.D. Student
Model category for his model on Power System with a Transmission Line operating at low frequency

Abstract:
The transmission of electric power with alternating current (AC) faces constraints that are inherent both to the stable operation of the power system and to the physical properties of the transmission lines or cables. Many factors stand to motivate the alleviation of these constraints without a need to construct new transmission lines or cables. One demonstrated method to accomplish this is to lower the electrical frequency of a transmission branch or section of the network, an approach known as low frequency AC (LFAC) transmission. The resulting lower reactance of the lines improves the transmission under the stability concerns which arise with long, inductive overhead lines, as well as under thermal concerns that can be substantial due to charging currents in underground cables. In this order of ideas, the Modular Multilevel Matrix Converter (MMMC) offers the necessary frequency conversion for low-frequency transmission, while allowing controllability of power through the transmission line.

For this reason, this presentation focuses on the EMTP modeling and simulation of this converter starting from a design that meets the typical voltage and power requirements for a transmission line. The averaged model of the converter has been implemented to evaluate its performance as a frequency converter and how it interacts with the power system. Simulations have been carried out under nominal operating conditions in a study case power system.

Tag(s): EMTP, Prize winners, IBR, Protection, Power system, Transmission Line, Low frequency,

Optimization of Control Parameters of Grid-Connected PV System in EMTP845

Abstract
It is observed that the controller gain parameters of the PV model have a significant impact on the PV plant’s response during the fault recovery and the PV plant’s interaction with the rest of th... see moree system in general. Manual tuning of the PV park parameter considering multiple fault and contingency scenarios is a time-consuming task and might even be impossible. Optimization techniques such as particle swarm optimization (PSO) can be used to optimize the gain parameters considering fault/ contingency scenarios. The presentation will talk about the implementation of PSO in EMTP using javascript to optimize PV park controller gain parameters.

Tag(s): pv plant, ibr, pso, optimization, scripting, pll, inverter control, inverter based resources, DER

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.

Impact of Renewables on System Protection768

Abstract
The presentation will describe how EMTP with its wind turbine model library, as well as its relay model library are being used at EPRI research projects to perform case studies for EPRI member utiliti... see morees.

The integration of inverter based resources (IBRs) into power systems introduces several technical challenges. One major challenge is the impact on system protection, resulting from the complex fault response characteristics of IBRs which are interfaced with the grid through power electronics and do not behave similar to conventional synchronous generators. EPRI is investigating the performance of legacy protection schemes in systems with high levels of IBRs, and potential misoperations which will compromise the grid reliability.