Increased efficiency and reduced risks during project execution – with Digital Switchgear

Medium-voltage switchgear is a key element in electrical infrastructure projects

There are numerous challenges when planning and executing electrical infrastructure projects in the oil, gas and chemical industries (tight time schedules, tight budgets, and limited space available in the yard or inside the E-House…), so optimization is a must: Voltage levels, number of transformers and switchgear panels, and their layout in an E-House. And once the design is complete and orders have possibly already been placed, the project requirements may change –  motor sizes increase, or more savings or additional space must be found leading to another round of optimization and re-design, with all the time, costs and extended project completion time involved.

Medium-voltage switchgear is a key element in electrical infrastructure projects. With the drive for greater efficiency and innovation, ABB’s specialists have reviewed and assessed all project pain points and customer requirements and have created a solution based on state-of-the-art technologies. These experts thought about how best to build in switchgear senorsflexibility to cope with changing load flows (in the sense of “one size fits all”) to easily enable last minute changes. They also thought about how switchgear can have a quicker delivery time and how to further reduce the time and costs during engineering, installation and testing on site (when time pressure and labor rates are at the highest), and about how switchgear can save additional space and provide even safer environments than the industry norm.

… and came up with Digital Switchgear! 

Digital Switchgear addresses the pain points experienced by end users and EPCs (engineering, procurement, construction companies) all over the world. It is based on a combination of smart technologies: current and voltage sensors and IEC 61850 communication incorporated in modern numerical protection relays – as part of ABB’s reliable and well-proven medium-voltage switchgear.

Key item 1: IEC 61850 and modern numerical protection relays to simplify wiring, enhance flexibility and improve robustness


ABB’s Relion® protection relays implement the core values of IEC 61850. GOOSE (Generic Object Oriented Substation Events) is used for fast and most reliable horizontal communication  (e.g. for inter-tripping, inter-locking and blocking) simplifying project execution and operation, with significant time and cost savings:

  • A common look and feel, menu guidance and software tool enable ease of use, engineering and most intuitive handling.
  • Native IEC 61850 technology saves time and costs during engineering, testing, installation & commissioning and provides fully factory pre-tested logics and communication that can be “plug-and-play” installed on site, still with the flexibility of last-minute changes through quick and easy re-programming, without the need for costly and time-consuming physical re-wiring. This offsets one of the main risks and reasons for costly change orders and delays in project execution.
  • Enables most reliable and fastest performance. The signals are exchanged with more than double the speed of conventional hardwiring. Further, the continuous self- and cross-supervision of all relays and connections ensures that any loss of a component is immediately indicated as soon as the loss occurs. The electrician will know exactly where to go and what to look for. In comparison, a conventional wire breakage would only be noticed once its functioning is needed, and that’s when it is already too late. ABB’s Relion with IEC 61850 GOOSE simply implies fewer risks and “headaches” during operation.
Key item 2: Current and voltage sensors – avoiding endless loops for clarification while reducing risk of failures


ABB’s sensors are based on advanced measurement principles that achieve significant benefits over instrument transformers:

  • Current sensors are based on the Rogowski-coil principle (accuracy of class 0.5 for both, metering and protection)
  • Voltage sensors are based on the resistive divider principle (accuracy of class 0.5 for metering and of class 3P for protection).

They are optimally designed to fit into the switchgear, while allowing enough space in case additional CTs are required, e.g. for transformer differential protection or for utility hand-over metering.


The linear characteristic of current sensors vs. instrument transformers allows reliable operation in a wide range of primary currents and hence flexibility towards changing load flows in the sense of “one-size-fits-all”. The use of sensors saves additional space and therefore increases competitiveness (no need for dedicated bus VT panels, which reduces footprint required inside the E-House).

Further, traditional current transformers (CT) and voltage transformers (VT) are sensitive to incorrect handling, e.g. during testing or maintenance. Sensors eliminate this risk of failure and the related costly downtime, they increase safety and maximize system uptime

 Digital Switchgear addresses key elements for improving project execution and switchgear operation – flexibility towards last minute changes and quicker delivery time while increasing reliability and safety. You can learn more here.

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About the author

Thomas Schmidtchen

I am the global segment manager for oil, gas and chemicals for ABB’s Medium Voltage Products business and in this role, I am constantly discussing technology and looking for innovations that help make our customers better. Digital Switchgear is specifically exciting, as it has the potential to truly be a game changer and revolutionize the power distribution landscape.
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