At CIGRE 2024, I attended the B5 Study Committee on Protection and Automation and read most of the papers submitted. Here is a summary of my findings on what’s new.

The papers submitted to the B5 committee reveal several key trends and findings related to advancements in digital substations, process bus technologies, centralization, and virtualization.

1. IEC 61850 and Process Bus Adoption:

• Many papers emphasize the growing adoption of IEC 61850 for digital substation automation. This standard is pivotal in enabling interoperable, flexible, and efficient substation systems. It has helped transition from traditional copper-wired communications to process bus systems, improving data exchange, security, and functionality.
• The application of IEC 61850 process bus technology in both new and existing substations is being explored extensively. Projects have demonstrated significant benefits, including better integration, reduced wiring, and enhanced real-time control

2. Centralized and Partially Centralized Protection and Control:

• Centralization of protection and control systems is highlighted as a promising approach. Many papers discuss a Centralized Protection and Control (CPC) architecture, where protection functions are moved from individual relays to a centralized system. Consolidating hardware enables better management, flexibility, and potentially lower costs.
• The concept of partially centralized systems, where some functions remain distributed, was also discussed. This hybrid approach balances reliability with centralization benefits.

3. Virtualization and Software-Defined Substations:

• The shift towards virtualization was presented as a significant development in protection and control systems. Virtualization decouples software applications from specific hardware, enabling deployment on more powerful and flexible computing platforms. This helps reduce hardware footprint, simplifies updates, and enhances scalability.
• Containerization of applications is compared to virtual machines, with containers offering advantages in terms of resource efficiency and scalability. Performance tests have shown that virtualized protection applications can meet the real-time performance demands comparable to embedded systems.

5. Engineering and Interoperability:

• Top-down engineering based on IEC 61850 is highlighted for its system design and commissioning efficiency. Although it may require a higher initial investment, it reduces long-term costs, streamlines future projects, and improves interoperability across different devices.
• The Process Interface Unit (PIU) specification evolves the Merging Units to add local data processing at the equipment interface point. PIUs will be a critical component of digital substation architectures, collecting all useful data generated by the sensors within the substation.
• Failure to keep accurate time synchronization is a significant issue as it can disable essential protection function in addition to providing erroneous information for forensic analysis. How to ensure time synchronization at all time, with backup schemes based on the Precision Time Protocol, must be designed carefully.
• Digital substations will depend heavily on network availability. So designing redundant network schemes with PRP or HSR approach is also critical to success. Overall, PRP seems to be more adapted for future complex substations.

These findings collectively showcase the ongoing digital transformation in substations, emphasizing efficiency, flexibility, and centralization as key themes.

In future blogs, I will discuss in more details the following topics:

• What is the difference between a PIU and a MU?
• How can we solve time synchronization issues?
• Is PRP better than HSR?
• Pros and Cons of Centralized v. Virtualized Protection and Control (CPC v. VPC)
• An overview of Process Bus and Sample Values as per the IEC 61850 standard