As utilities modernise their networks to meet growing demand and increasing complexity, the digital substation has become a cornerstone of next-generation grid infrastructure.
Digital substation technology enables real-time data exchange and more efficient grid operations.
The digital substation reflects the shift from analogue, hardware-intensive systems to software-driven data-centric architectures.
Replacing copper with fibre
One of the defining features is the implementation of a process bus, based on the IEC 61850 standard. This enables the replacement of thousands of traditional copper signalling wires with fiberoptic communication networks.
Instead of transmitting electrical signals through physical connections, data is digitised at the source and communicated across the substation via a secure, standardised network. This simplifies wiring significantly, reduces installation time, and enhances system flexibility.
Mohamed Hosseiny, Oversight Country Managing Director for Africa at Hitachi Energy, emphasises that: “The shift from copper to fibre fundamentally improves how information flows across the substation, enabling faster response times and more efficient operations.”
The process bus
The process bus serves as the backbone of the digital substation, connecting high-voltage equipment in the switchyard to protection and control systems in the control room. Through this architecture, real-time measurement data and status information can be shared seamlessly across devices, eliminating the need for complex point-to-point wiring. As well as improving performance this supports interoperability between different vendors, enabling utilities to build flexible, future-ready systems.
Bridging legacy and digital systems
A key challenge for many utilities is how to modernise existing substations without replacing all installed equipment. This is where solutions such as Hitachi Energy’s SAM600 process bus I/O system play a critical role.
SAM600 enables conventional instrument transformers and legacy equipment to integrate with modern digital systems, effectively bridging the gap between analogue and digital environments.
“Utilities do not need to start from scratch,” Hosseiny highlights. “With solutions like SAM600, they can modernise incrementally, upgrading performance and safety while protecting existing investments.”
Enhancing safety and reducing downtime
By digitising current and voltage signals and transmitting them via optical fibre, digital substations significantly reduce the risks associated with handling high-voltage circuits.
Another advantage is that modular and pre-tested systems streamline installation and commissioning, reducing outage times during upgrades or maintenance.
Continuous monitoring of substation components has the further benefit of enabling predictive maintenance, allowing operators to identify and address potential issues before they lead to failures.
Data-driven performance and asset management
Digital substations generate vast amounts of data, from equipment health metrics to real-time operational conditions. Advanced asset management systems can analyse this data to optimise performance, improve maintenance planning, and extend the lifespan of critical infrastructure.
These capabilities are particularly valuable in environments where reliability is paramount, and unplanned outages carry serious economic and social costs.
Future-ready infrastructure
With the ability to process millions of data points and support rapid data exchange across the grid, digital substations are designed to meet current and future demands. They provide the foundation for advanced applications such as remote operation, automated fault detection, and integration with broader, smart grid ecosystems.
“For utilities, digital substations are a step towards the future – towards enabling smarter, more resilient and more sustainable energy systems,” says Hosseiny.
For more information visit: www.hitachienergy.com/
