ZUG, Switzerland, Dec 1, 2025 – Siemens has introduced the Siprotec 5 Precision Time Protocol (PTP) Grandmaster Clocks (GMC) to deliver precise time synchronization for digital substations. The system supports protection functions, reduces vulnerability to external disturbances, and adds security features to improve grid reliability.
Siemens has added integrated PTP Grandmaster Clocks to its Siprotec 5 devices to support precise time synchronization in digital substations. The system separates sample synchronization from global time synchronization by using internal time sources. The devices follow the IEEE 1588v2/PTP standard, use internal oscillators instead of external Global Navigation Satellite System (GNSS) signals to maintain accurate synchronization.
A key feature is Siemens’ patent-pending Seamless PTP grandmaster changeover technology built into Siprotec 5 devices. When primary clocks come back online, they first align with the active backup clocks before taking over. This prevents time-base jumps during switchover and keeps protection functions available.
The synchronization enables process bus networks to operate autonomously without access points, strengthening cybersecurity by isolating the process bus from the station bus network.
Siemens’ approach improves time synchronization by removing dependence on external GNSS signals. Conventional digital substations often use redundant GNSS-based grandmaster clocks, but these systems can be disrupted by solar storms, jamming, or spoofing. Such events can trigger time-base jumps that force merging units to resynchronize and disable protection functions. These interruptions can take equipment out of service or cause false trips, affecting grid stability and increasing operating costs. Siemens’ method reduces these risks and keeps protection functions available.
“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.”
Source: Siemens
About Siemens Smart Infrastructure
Siemens Smart Infrastructure, a division of Siemens AG, is headquartered in Zug, Switzerland. The division integrates energy systems, buildings and industrial processes to improve efficiency and support modern infrastructure needs. It provides HVAC controls, fire safety systems, security technologies, energy-performance services, grid-resilience tools and electric-vehicle charging equipment. Its offerings serve sectors such as data centers, energy and manufacturing. The division develops systems that span the energy value chain, from power generation to end use, and focuses on addressing challenges related to urbanization and climate change. It also places emphasis on cybersecurity to support secure and reliable operation in increasingly digital environments. Siemens Smart Infrastructure employed about 79,000 people worldwide as of 2025.
About Siemens AG
Siemens AG, headquartered in Munich and Berlin, Germany, is a global technology company focused on industry, infrastructure, mobility and healthcare. Founded in 1847, the company develops industrial automation systems, digitalization technologies, energy-efficient equipment and medical diagnostic systems. Siemens applies industrial and generative AI to improve efficiency and operational performance across manufacturing, infrastructure and transportation. Its work combines physical systems with digital tools to support industrial processes, smart infrastructure and connected mobility. Siemens holds a majority stake in Siemens Healthineers, a medical technology company specializing in diagnostics and healthcare systems. The company is a major employer with more than 300,000 people worldwide and has significant operations in Germany.