Smart medium voltage switchgear with LPITs and IEC 61850 – experiences after 10 years and the next evolution

Over the past decade, significant advancements have been made in medium voltage (MV) switchgear technology, driven by the need for enhanced reliability, efficiency, and safety in electrical distribution systems. This paper explores the experiences with Smart (Digital) MV Switchgear in primary distribution applications, focusing on key components such as Low-Power Instrument transformers (Rogowski coil current sensors and voltage sensors based on voltage dividers), and IEC 61850 communication, including GOOSE and Process bus (Sampled Measured Values). The paper provides insight into how the main technology gaps have been resolved in the last decade. Additionally, it discusses the future outlook and contributions of Smart MV Switchgear to sustainable and resilient MV networks. The advancements in Low-power passive Instrument transformers LPITs), offering higher accuracy and better linearity, have enabled more precise monitoring and protection of electrical networks. The adoption of IEC 61850 communication standards has revolutionized MV switchgear systems by facilitating seamless interoperability and real-time data exchange, reducing wiring needs, lowering installation costs, and improving system flexibility and scalability. This paper aims to provide utility and industry professionals with a detailed understanding of these developments and their practical implications, supporting informed decision-making and strategic planning in electrical distribution.