Dec. 12, 2025 – Siemens has unveiled its latest innovation for energy infrastructure: the Siprotec 5 Precision Time Protocol (PTP) Grandmaster Clocks (GMC). Built to secure the backbone of modern power grids, this solution ensures resilient, fail-safe time synchronization for digital substations, safeguarding critical protection functions from disruption, shielding against external disturbances and strengthening cybersecurity to boost overall grid reliability.
In today's digital power grid, precise time synchronization is essential for protection systems. While many applications require globally accurate time signals, sampled values within process bus systems primarily depend on consistent local precision rather than external global sources.
Siemens' solution separates sample synchronization from global time synchronization using specialized internal time sources. The Siprotec 5 devices, equipped with integrated PTP Grandmaster Clocks compliant with IEEE 1588v2/PTP standard, operate independently from external Global Navigation Satellite System (GNSS) signals. Instead, they use internal oscillators as time references for precise synchronization.
A key feature of this approach is Siemens' patent-pending Seamless PTP grandmaster changeover technology, built into Siprotec 5 devices. This ensures that when primary clocks return, they first align with active backup clocks before resuming their role. In doing so, disruptive time base jumps during switchovers are prevented, keeping protection functions continuously available.
The specialized synchronization enables process bus networks in digital switchgears to operate autonomously without external access points, significantly strengthening cybersecurity by isolating the process bus from the station bus network.
Conventional digital substation architectures often rely on redundant GNSS-based grandmaster clocks. However, even with redundancy, they remain vulnerable: disturbances to GNSS signals, whether from natural phenomena like solar storms or intentional interference such as jamming and spoofing, can cause disruptive "jumps" in the time base. Such disruptions force merging units to resynchronize, temporarily disabling critical protection functions and can lead to unnecessary removal of equipment from service or even cause false tripping events, impacting grid stability and increasing operational costs. Siemens' new solution mitigates these risks, ensuring uninterrupted, secure operation.
"This technology directly addresses one of the most critical vulnerabilities in digital substations," said Onyeche Tifase, vice president Product Lifecycle Management at Siemens Smart Infrastructure. "By keeping protection functions active through any time source change and shielding process networks from external threats, we are helping customers operate safer, more reliable and more sustainable power systems."
About Siemens AG
Siemens AG (Berlin and Munich) is a leading technology company focused on industry, infrastructure, mobility and healthcare. The company’s purpose is to create technology to transform the everyday, for everyone. By combining the real and the digital worlds, Siemens empowers customers to accelerate their digital and sustainability transformations, making factories more efficient, cities more livable and transportation more sustainable. A leader in industrial AI, Siemens leverages its deep domain know-how to apply AI–including generative AI–to real-world applications, making AI accessible and impactful for customers across diverse industries. Siemens also owns a majority stake in the publicly listed company Siemens Healthineers, a leading global medical technology provider pioneering breakthroughs in healthcare. For everyone. Everywhere. Sustainably.
