IEC 61850 beyond compliance: A case study of modernizing automation systems in transmission power substations in Emirate of Dubai towards smart grid

Abstract

A substation control and monitoring system (SCMS) is composed of digitally connected devices that exchange information using multiple communications protocols to protect, control, and monitor entire substation automation applications remotely from respective control centers. It is also essential to combine cybersecurity within the SCMS. In an effort to move towards smart grid, the Dubai Electricity & Water Authority (DEWA) initiated a long-term contract for the supply, installation, testing, and commissioning of 33 substations (132/11 kV) with modern automation systems for transmission power substations. DEWA has very strict requirements in terms of system availability, reliability, performance, cybersecurity, Ethernet network resiliency, and protection and communications redundancy. An HMI is included in the SCMS for local indication and control. Status, metering, and control data to the local HMI and remote utility enterprise system is provided by a redundant SCADA system. Reliable and secure communications to support mission-critical, high-speed protection schemes is achieved by an Ethernet network of utility-grade operational technology (OT) switches, not IT switches. The Ethernet network uses a modified ladder topology with IEC 62439 Part 1 Spanning Tree Algorithm (STA) via Rapid Spanning Tree Protocol (RSTP) for network resiliency and IEC 62439 Part 3 Parallel Redundancy Protocol (PRP) for message duplication. Data segregation and traffic control in the SCMS network is provided by IEEE 802.1 VLANs. The data acquisition and control along with engineering access and event report collection is accomplished using manufacturing message specification (MMS), whereas high-speed signal exchange for peer-to-peer protection schemes is accomplished using GOOSE communications protocols from the IEC 61850 communications standard. The DEWA technical SCMS specifications were built around the concept of future proofing and backward compatibility to support the evolution of smart grid capabilities by accepting smart technological advancements and future development of substation automation system features. It is strongly believed that the technical improvements made in DEWA specifications will lay a solid foundation for a sustainable automation system in DEWA over the years to come. Because DEWA is aware of the risks of digitizing substation communications networks and the recent increase in the number of cyberattacks against utilities that involve abusing vulnerabilities in the security of their communications networks, DEWA has strict cybersecurity requirements to prevent cyberinduced power outages that could potentially disrupt an electric power grid. The SCMS was designed with the holistic approach of a defense-in-depth philosophy, including supply chain security and physical security. The DEWA SCMS security design relies on a multilayer security zone approach to provide a scalable cybersecurity solution that automates tasks, streamlines operations, and improves performance. This paper discusses DEWA system requirements developed to facilitate the safe, reliable, and economical delivery of power in Emirate of Dubai. This is followed by a discussion of various engineering decisions that resulted from lessons learned during the design stage of the DEWA transmission power substation automation system to ensure that the system is ready for future smart grid requirements. Various analysis tools and testing techniques are described in the paper that were used to quantify the performance attributes of the IEC 61850-based system design. This project proves that with the right engineering design and a properly configured Ethernet network that uses best engineering practices for OT, performance, interoperability, and compliance to standards can coexist.