Deep Water High Capacity Dynamic Power Cables; Recent Developments

Abstract

The design, installation and operation of offshore high power static (seabed) cables are mature technology areas. However, the key missing component in the power transmission system is the water-column portion of the cable that links the floating facility with the static cable on the seabed, the electrical equivalent of a pipeline riser. When such dynamic power cable enabling technology matures it will allow the removal of power generation equipment from platforms, interconnection between offshore installations, utilization of stranded gas for power generation (GTW -Gas to Wire) and its transmission by subsea power networks to the customer, and the transmission to land of power from offshore deep water renewable energy devices. This paper reviews recent developments in dynamic power cable technology. It discusses the range of configurations and technical requirements required to deliver a fit-for-purpose deep-water product. In particular, mechanical fatigue is addressed together with the need for field specific designs to optimize configurations. Conclusions from the PowerCab JIP recently completed by BPP-Cables are presented. The JIP delivered a prototype 100MW 132kV dynamic AC power cable optimized for extended service life with account taken of the manufacturing and installation issues. The cable has been fatigue tested to verify electrical and mechanical performance in conditions representative of the West of Shetlands.