HHI Simplifies Large Container Ship Power System
South Korean shipbuilder Hyundai Heavy Industries (HHI) has developed a simplified power system for 15,000-TEU container ships.
DNV GL has awarded an Approval in Principle (AIP) for the shipbuilder’s multi-grid design which devides the power system into two: essential loads required to operate the ship and service loads needed, for example, to keep reefers at proper temperatures.
For conventional container ships, onboard electrical equipment is typically powered at a low voltage level - 440V or less. As container ships have become larger, however, the total amount of electricity required has grown, calling for 6.6kV or higher-voltage power systems onboard. As a result, installation of up to eight large-capacity transformers to convert high voltages into low voltages has become inevitable.
The multi-grid power system lowers the capacity of each system, allowing low-voltage power distribution to replace the existing high-voltage power distribution. No voltage conversion means no large transformers weighing up to 64 tons in aggregate that would otherwise be loaded onto the ship, while also allowing for an extra loader capacity of 60 FEU thanks to better space utilization.
The financial boon offered by the elimination of voltage conversion is approximately $320,000 saved from onboard power system equipment per vessel, says HHI. Further, the flexibility in the amount of power supplied in alignment with the quantity of the containerized cargo drives up energy efficiency of the ship, removing the unnecessary energy consumption in the conventional power systems.
HHI as applied for 12 patents in South Korea and also filed for an overseas patent in the E.U., Canada, China and Japan.