Jorge Cardenas 
Adneli Consultant, Spain
Jorge.cardenas@adneli.com 
www.adneli.com

Citar: J. PAIME, 2025, 3, 1-6
April 2025

Abstract

The increasing penetration of IBRs in power systems presents challenges for conventional protection schemes, particularly line distance protection. These challenges are pronounced in scenarios involving WI sources, where a transmission line connects a strong energy source at one end and a weak or renewable-based source at the other one. In contrast, differential protection schemes, used for generators, lines, and transformers, have demonstrated robust performance in grids with high IBR penetration. This paper analyses the performance of distance and line differential protection for lines in networks with high IBR penetration levels using the Electromagnetic Transient Program (EMT) ATPDraw and the IEEE 9-Bus model. Additionally, it examines the behaviour of other parameters, such as sequence voltages and currents, to explore their potential for enhancing protection schemes. Based on the findings, the paper proposes alternative and complementary solutions, including new protection schemes for both primary and backup systems, with examples of novel approaches to improve fault identification in IBR-dominated grids.
Keywords: Inverter-Based Resources (IBRs), Point of connection (POI), Weak infeed (WI).

Resumen

La creciente penetración de fuentes de energía basadas en inversores (IBR, por sus siglas en inglés) en los sistemas eléctricos plantea desafíos para los esquemas convencionales de protección, particularmente para la protección de distancia de línea. Estos desafíos se acentúan en escenarios que involucran fuentes de tipo Weak-Infeed (WI), donde una línea de transmisión conecta una fuente de energía fuerte en un extremo y una fuente débil o basada en energías renovables en el otro. En contraste, los esquemas de protección diferencial, utilizados en generadores, líneas y transformadores, han demostrado un desempeño robusto en redes con alta penetración de IBR.

Este artículo analiza el comportamiento de la protección de distancia y de la protección diferencial de línea en redes con altos niveles de penetración de IBR, utilizando el programa de transitorios electromagnéticos Electromagnetic Transient Program (EMT) ATPDraw y el modelo IEEE de 9 barras. Adicionalmente, se examina el comportamiento de otros parámetros, como las tensiones y corrientes de secuencia, para explorar su potencial en el mejoramiento de los esquemas de protección.

Con base en los hallazgos, el artículo propone soluciones alternativas y complementarias, incluyendo nuevos esquemas de protección tanto primaria como de respaldo, con ejemplos de enfoques novedosos para mejorar la identificación de fallas en redes dominadas por IBR.

1      Introduction

To enhance the visualization and understanding of infeed effects, a grid model shown in Figure 1 was implemented using the classical EMT software ATPDraw. The model is based on the classical IEEE 9-BUS system, as described in references [1,2], with the addition of two extra buses: BUS10, connected via a 30 km transmission line, and BUS11, connected via another line of identical characteristics but connecting a renewable generation (wind type 3 - doubly-fed asynchronous generator - or solar PV) [3]. The model incorporates distance relays (phase and ground) [4] as well and a basic model for a line differential protection (87L) in line BUS11-BUS7.

The models used to represent power system components, such as generators and relays, have been simplified and may not fully reflect real-world operation in other network topologies or with specific technologies, such as inverters, wind turbines, or devices with incorporated limiters and protection features. Despite these limitations, the observed performance of the devices in this study is expected to closely align with realworld scenarios. For practical applications, it is always recommended to use manufacturer-provided models for more accurate results. All relays employed primary voltage and current inputs, and impedance values were expressed in primary ohms.

Más detalles en el documento adjunto.
https://doc.uni75paime.org/AD_178_2025_Faults_with_IBR_presence.pdf

5      Conclusions

•  Communications systems are integral to modern protection systems, but they introduce additional dependency. The protection schemes proposed mitigate potential drawbacks.

•  Remote inter-tripping schemes, like those proposed in reference [11], can also be used to clear faults on adjacent lines. These schemes apply similar criteria to conventional weak-infeed methods but are designed for remote backup protection.

•  Selective backup protection is possible if we can rely on the communication systems as an integral part of any protection scheme.

•  EMT software analysis is increasingly required to evaluate electrical phenomena in relays. However, due to limitations in modelling large grids, a new approach using "dynamic phasors" has been proposed to overcome these challenges. [17]

6      References

[1]  Paul M. Anderson, A.A. Fouad. “Power System Control and Stability.” IEEE Press.

[2]  Perry Clements. “IEEE_9BUS_LF.ACP”, 2016. [3] Francisco J. Peñaloza, “Demo case PV50MW_MPPT1.” Aug. 26, 2015.

[4]     Hans Kr. Høidalen. “Impedance element relay.” Dec. 11, 2014.

[5]     Rossano Musca, Gaetano Zizzo, Alessandro Manunza.

“Grid-Following and Grid-Forming MODELS in ATPEMTP for Power Systems Simulation.” University of Palermo, Italy, 978-88-87237-55-9 ©2022 AEIT.

[6]     L90 Line current differential system, GE Vernova.

[7]     A. P. Sakis Meliopoulos, Fellow, IEEE, George J. Cokkinides, Senior Member, IEEE, Zhenyu Tan, Student Member, IEEE, Sungyun Choi, Student Member, IEEE, Yonghee Lee, Student Member, IEEE, Paul Myrda, Senior Member, IEEE. “Setting-Less Protection: Feasibility Study.” 013 46th Hawaii International Conference on System Sciences.

[8]     Migrate Horizon 2020 project (https://www.h2020migrate.eu/).

[9]     Jorge Cardenas. “Line Protection Performance during faults in networks with Solar PV and Wind renewable energy.” www.adneli.com/downloads. 2022.

[10]  Bogdan Kasztenny. “Distance Elements for Line Protection Applications Near Unconventional Sources.” Schweitzer Engineering Laboratories, Inc.

[11]  Carlos Aguilar. “Grid backup protection on renewables substation plants:  zone 3, overcurrent and other options”, GCC, 2020.

[12]  M S Saha, J Izykowski, E Rosolowski. “Fault Location on Power Networks,” Springer-Verlag London Limited, 2010.

[13]  ATN. “Análisis de la función de localización de fallas.” 16 nov. 2012.

[14]  elumina™ PLATFORM. GE Vernova.

[15]  Jorge Cardenas. “Selective Backup Protection for AC HV and EHV Transmission Lines.” Actual Trends in Development of Power System Protection and Automation. 01 June – 05 June 2015, Sochi.

[16]  Jorge Cardenas. “Impact of Network Protection in the prevention of Major Events in the Power System.” CIGRÉ Russia, 2013.

[17]  Mario Paolone, Trevor Gaunt, Xavier Guillaud, Xavier Guillaud, Sakis Meliopoulos, Antonello Monti, Thierry Van Cutsem, Vijay Vittal, Costas Vournas. “Fundamentals of Power Systems Modelling in the Presence of ConverterInterfaced Generation.” Electric Power Systems Research. December 2020.