Walvis Bay, with its large bay and sand dunes, is the principal home of Namibia's fishing industry. One crucial requirement for this industry is an uninterrupted supply of power to safeguard cold chain management of the seafood, from harvesting out at sea right through to the consumer. To meet increasing power demands in the region and to ensure an uninterrupted power supply, the regional power distributor, Erongo RED, has made investments to upgrade the existing electrical network.
The Erongo Regional Electricity Distributor Company, commonly known as Erongo RED, is the electricity distributor for the Erongo region in Namibia. The company delivers electricity to homes, industrial customers and businesses in the region, located in the Namib Desert, which runs the length of the Namibian coast. In this area, the fishing industry is one of the cornerstones of the economy and Walvis Bay is the country's largest commercial port.
In the fishing industry continuous power supply is crucial to ensure proper cold chain management, as seafood must be refrigerated continuously, without interruption, to keep it fresh. Companies in the industry make vast investments to ensure the seafood is handled correctly, starting with on-board refrigeration to refrigerated trucks, and high demands for a high-performing and secure shore-side electricity infrastructure for cold storage, processing and canning facilities. On top of serving the needs of the fishing industry, the upgrade project will benefit the port expansion, new mall, mass housing and residential customers alike.
Already at the negotiation phase of this project, the customer stressed the requirement for reliable interoperability between the different protection relays and the control system, since the introduction of ABB's products into Erongo RED's environment would create a multi-vendor environment. The existing control system is from another vendor and ABB's Relion® protection relays would be introduced alongside existing third party relays.
To meet Erongo RED's requirements, ABB supplied a solution based on a double busbar UniGear ZS1 switchgear, which is capable of distributing 120MW at 11kV. The protection and control scheme is based on ABB's Relion protection relays to form a reliable and highly integrated system for maximum redundancy. In power systems, redundancy is implemented to lessen or eliminate the impact when a fault occurs. In this solution, the Relion 620 series protection relay sends the command to disconnect the busbar where the fault has occurred, and to connect the healthy busbar to supply the power. Using this high-performing solution, the customer achieves uninterrupted power supply while transferring loads between the busbars. For a medium-voltage power system of this size, this is one of the largest uninterrupted load transfer systems in the world.
To ensure power system reliability and performance, the solution utilizes the benefits of horizontal GOOSE-based communication technology between the protection and control devices. GOOSE (Generic Object Oriented Substation Events) is part of the IEC 61850 standard for power system automation. To secure the continuity of communication between the protection relays, the Parallel Redundancy Protocol (PRP) was used.
