Two new oil and gas platforms located approximately 160 km offshore on the west coast of Norway are being electrified through a high-voltage AC (HVAC) power-from-shore system. The project aims to replace local offshore power generation with electricity supplied from the mainland grid, significantly reducing CO₂ emissions. With a total submarine cable length of 255 km, the installation represents a world-record HVAC transmission distance for offshore platform electrification.
To enable reliable operation over such an unprecedented cable length, a dedicated reactive power compensation substation has been developed, combining passive compensation with advanced FACTS technologies. The solution integrates shunt compensation through a STATCOM and series compensation through a thyristor-controlled series capacitor (TCSC), providing dynamic voltage control at the offshore platforms while minimizing reactive power exchange at the point of connection to the mainland grid.
The presentation focuses on how key technical challenges associated with long-distance HVAC transmission have been addressed. These include voltage variations during load rejection, electrical faults, energization of the whole system, and mitigation of resonance phenomena. The coordinated STATCOM and TCSC control strategy ensures voltage stability, limits reactive power transfer, and maintains robust system performance under both steady-state and transient operating conditions.
Presented by: Hector Latorre, Hitachi Energy