220kV North Auckland and Northland (NAaN) Project in Auckland, New Zealand

摘要

The 220kV NAaN project consists of approximately 36 km of new 220 kV underground cable circuits installed between Albany substation in Auckland's north and Pakuranga substation in the east providing additional transmission capacity to North Auckland and the Northland area. Contracts were awarded in December 2010, project works commenced in January 2011 and the new 220 kV cable circuits were successfully energised in early 2014. The NAaN Project comprised four sections as shown in Table 1. Section 1 & 2 Scope of Works (SoW) included design, manufacture, install and ccommissioning of 220kV underground cable circuits between Albany substation and Hobson substation in Auckland New Zealand. The key challenges facing the project team on this project were: 1. Design, manufacture & installation of 220 kV 2500 mm~2 & 1600 mm~2 copper-enamelled (CuE) cables & accessories including transition joints. 2. Design & verification of the cable support structure on the 1.4 km long Auckland Harbour Bridge (AHB) to cater for both horizontal and vertical bridge movements. 3. Design of the dilatation mechanism for the expansion joints on the AHB and verification of the mechanical behaviour of cable when subjected to simulated thermo-mechanical and seismic movement and bridge vibration. 4. Installation of the 220 kV cables & associated optical fibre cables in a single pull without joints on the constantly vibrating AHB structure. 5. Determination of mechanical characteristics & the thermo-mechanical behaviour of the 220 kV cables. 6. Design of prototype testing rigs & setups to verify the effectiveness of snaking arrangement.