Deployment of multipoint grid control applications over mixed communication networks using protection signaling devices

SDH, optical transport networks, analogue PLC systems, and more recently packet-based transport technologies such as MPLS-TP. While robust, these solutions were primarily designed for bilateral signalling and static grid topologies.

The evolution of power systems—driven by renewable integration, dynamic topologies, and stability requirements—has expanded the role of protection signalling. Beyond conventional functions, it now supports synchronized wide-area communication, enabling real-time interaction between substations and advanced wide-area protection and control applications, including remedial action schemes (RAS). This highlights the limitations of traditional pointto-point signalling architectures.

This paper addresses wide-area multipoint protection signalling as an enabling technology for these evolving needs. By combining commands from multiple substations over heterogeneous, possibly multisegment, communication links, multipoint signalling maintains the stringent performance requirements of wide-area protection applications, typically within tens of milliseconds.

A critical aspect is the coexistence of multiple migration paths. Protection signalling within substations is moving from conventional wired I/O to IEC 61850 over Ethernet LANs, while wide-area networks migrate from TDM to packet-based networks. These transitions progress at different paces, requiring architectures that flexibly integrate conventional and emerging communication technologies over extended periods.

As wide-area networks evolve toward full-mesh data exchange among substations, control centres, and data centres, multipoint protection signalling extends traditional Teleprotection concepts. However, this flexibility increases the complexity of system engineering, configuration, and validation.

System-level configuration, monitoring, and validation are therefore essential. Centralized engineering tools, supported by offline configuration and simulation, allow verification of distributed signalling logic and response-based behaviours before deployment, reducing engineering effort and configuration errors, and improving confidence during factory acceptance testing. Importantly, these tools can also serve as the existing Network

Management System (NMS) for ongoing monitoring, configuration updates, and upgrades after commissioning, providing continuity throughout the system lifecycle.

In summary, multipoint protection signalling represents a natural evolution of Teleprotection, enabling coordinated command generation across multiple substations to support wide-area protection and control applications. Traditional point-to-point architectures are increasingly limited for modern grids with dynamic topology and high renewable penetration, while heterogeneous and multisegment communication paths allow coexistence of legacy wired I/O,

TDM, and packet-based WAN technologies. Response-based signalling introduces additional design complexity, requiring careful attention to coordination logic, timing, and securityversus-dependability trade-offs. Reliable deployment of such systems relies on system-level engineering, and offline configuration and simulation capabilities, which can also be leveraged through the NMS, significantly reduce engineering effort and risk, particularly for complex multipoint architectures with distributed logic.