SuedLink HVDC, Germany: Connecting clean power

Designed to carry up to 4 GW of renewable electricity across 700 kilometers, SuedLink relies on advanced converter stations and transformers from Siemens Energy. These enable up to 2 GW of clean power transmission along critical sections (DC3) of the route.

Germany’s Energiewende demands a modern transmission system capable of moving vast amounts of renewable energy across long distances. The challenge: bridging the geographic gap between wind-rich northern regions and energy-intensive southern areas while minimizing losses and maintaining grid stability. SuedLink addresses this need with underground HVDC cables designed for high-capacity, low-loss transmission.

Siemens Energy provides cutting-edge HVDC converter stations based on modular multilevel converter (MMC) technology operating at ±525 kV. These stations enable efficient bidirectional power flow capability, reactive power control, and grid stability under dynamic load conditions.

A key component of the solution is the delivery of 14 custom-built HVDC Plus® converter transformers from Siemens Energy’s Nuremberg facility. Each single-phase unit is rated at 400 MVA and engineered for 400 kV operation, weighing 484 tons. Designed for ±525 kV HVDC applications, these transformers offer:

• High dielectric strength and low partial discharge performance 
• DC bias resilience and harmonic load tolerance 
• Optimized insulation systems for long-term reliability 
• Minimal losses and robust thermal performance under continuous high-voltage operation 

Siemens Energy’s scope within SuedLink includes converter stations and transformers that enable up to 2 GW of transmission capacity Germany’s Energiewende demands a modern transmission system capable of moving vast amounts of renewable energy across long distances - forming a vital part of the overall 4 GW corridor. This contribution ensures high efficiency and reliability where it matters most.