Editorial Opinions

Editorial – Issue 070 December 2024

Everything is Changing 

by Alex Apostolov, Editor-in-Chief

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The electric power grid is going through a significant transformation, driven by the integration of renewable energy sources, decentralized generation, and evolving technology. This represents a challenge to many PAC specialists that have experience only with conventional hardwired systems. That is why we decided to focus on the different issues related to PAC in the changing grid.

The shift from traditional synchronous generators to inverter-based distributed energy resources (IBDERs) poses unique challenges, impacting power quality, stability, and system reliability. These developments necessitate discussions that encompass emerging technologies, communication strategies, and cybersecurity, while also emphasizing the need for advanced engineering tools like IEC 61850 Substation Configuration Language (SCL).  

IBDERs, such as solar photovoltaic systems and wind turbines, are transforming the way electricity is generated and delivered. Unlike traditional synchronous generators, IBDERs rely on power electronics to interface with the grid, introducing characteristics such as low inertia and limited fault current contributions. These attributes challenge conventional protection schemes, which were designed to detect and isolate faults based on predictable fault current magnitudes.

Moreover, the increase of IBDERs affects power quality by introducing harmonics, voltage fluctuations, and phase imbalances. The variability of renewable energy sources intensifies these issues, making it essential to develop control strategies that improve power quality and maintain grid stability. Grid-forming inverters, and advanced harmonic filtering techniques are emerging solutions to address these challenges. However, their widespread adoption requires coordinated efforts in protection and control system design.

The availability of low-power instrument transformers (LPITs) has introduced new possibilities for grid monitoring and protection. LPITs offer benefits such as reduced size, improved accuracy, and compatibility with modern digital relays. These devices enable real-time data acquisition, which is critical for the precise control of IBDERs and other distributed resources.

Despite their advantages, the integration of LPITs into the grid requires careful consideration of their calibration, interoperability, and reliability under varying operating conditions. Discussions around protection and control must address the standardization of LPIT specifications and their integration with advanced digital protection schemes to ensure seamless operation in modern grids.

While communication-based solutions have revolutionized grid operations, they come with vulnerabilities, including delays, failures, and cybersecurity risks. Thus, it is equally essential to develop communication-independent solutions that ensure grid stability and reliability even in the absence of real-time data exchange. Examples include local control strategies embedded in grid-forming inverters, adaptive protection schemes, and decentralized decision-making processes that do not depend on external communication links.

Hybrid approaches that combine communication-based and independent solutions can provide resilience. For instance, protective relays equipped with local intelligence can operate autonomously during communication outages while synchronizing with centralized systems under normal conditions. This balance is critical to maintaining grid reliability in the face of increasing complexity and interconnectedness.

The IEC 61850 standard has become a cornerstone of modern power system automation. Its Substation Configuration Language (SCL) facilitates the design, integration, and operation of intelligent electronic devices (IEDs), offering a structured approach to managing the growing complexity of grid systems. SCL enables interoperability among devices from different manufacturers, streamlines the configuration of protection and control schemes, and supports advanced functionalities such as real-time monitoring and fault analysis.

In the context of IBDERs and decentralized grids, IEC 61850 provides a unified framework to manage diverse energy resources and communication networks. However, to fully leverage its potential, engineers need tools that simplify the application of SCL, from device modeling to system validation. These tools can help bridge the gap between traditional grid design practices and the dynamic requirements of modern systems.

As the power grid becomes increasingly digitized, cybersecurity emerges as a critical concern. The reliance on communication networks and interconnected devices exposes the grid to threats such as data breaches, malware, and coordinated cyberattacks. A compromised protection or control system could lead to widespread outages, equipment damage, or even safety hazards.

Addressing cybersecurity requires a multi-layered approach that includes robust encryption protocols, intrusion detection systems, and secure access controls. Furthermore, standards like IEC 62351, which complement IEC 61850, play a crucial role in ensuring the secure exchange of data within power systems. Cybersecurity training and awareness among grid operators and engineers are also vital to mitigate risks and ensure preparedness against evolving threats.

The challenges and opportunities presented by the changing electric power grid demand a holistic approach. Collaboration between utilities, regulators, researchers, and manufacturers is essential to drive innovation and standardization.

” All things are difficult before they are easy.”

Thomas Fuller