TenneT Connects North Sea Wind Farms with Crucial Testing by KEMA
TenneT, in collaboration with multiple contractors, has achieved a momentous milestone with the successful completion of a cutting-edge transformer substation in Wijk aan Zee. This groundbreaking facility, which encompasses both the Hollandse Kust Noord land station and the Wijk aan Zee 380kV substation, plays a pivotal role in integrating three new wind farms from the North Sea into the Netherlands’ high-voltage grid.
At the heart of this impressive substation lie two critical components: the land station, entrusted with the task of converting green electricity from the wind farms from 220 kilovolts to 380 kilovolts, and the switching station, and skillfully integrating it into the national 380 KV grid via the Beverwijk switching station.
The commissioning of this central project was preceded by meticulous release tests conducted by KEMA Labs, acting on behalf of various contractors associated with TenneT. These comprehensive tests sought to measure the occurrence of Corona within the substation – an electrical phenomenon unrelated to the Covid disease – characterized by crackling discharges in the air near high-voltage electrical installations. These discharges, often caused by sharp components, contamination, or assembly errors, can lead to bothersome noise and financial losses. To ensure a thorough assessment, KEMA scrutinized every part under tension throughout the vast expanse of the substation, equivalent to an astounding 23 football fields, making it an undertaking of considerable magnitude that spanned several weeks. The detection process hinged on a specialized camera that rendered air discharges visible as colored dots. The insights gleaned from the comprehensive report allowed subcontractors to promptly address any identified issues, guaranteeing optimal performance and efficiency.
Furthermore, KEMA Labs conducted a critical high voltage test on multiple 12 circuits using a Series Resonant test sets. This sophisticated test subjected the cable circuits to high voltage, necessitating the combination of two, three, and even four test sets due to the length and capacity of the cables. The meticulous setup, which took two days to assemble, enabled a test voltage of 374kV to be applied—1.7 times higher than the actual operational voltage of the cables—facilitating the detection of any potential manufacturing or assembly faults.
Not resting on their laurels, the final significant challenge lies ahead in September—testing a remarkable 69km long submarine cable leading to the wind farm park using five test sets. The successful execution of this undertaking demands intensive coordination between KEMA Labs and TenneT, resulting in a comprehensive test schedule that ensures all parties can carry out their activities within the stipulated timeframe. Regular consultations have been conducted to address safety concerns related to high voltage tests, construction activities, and on-site transport movements. Despite the complexity of the project, all tests were flawlessly executed as planned, with several cable circuits already seamlessly put into operation. As the curtains fall on this triumphant endeavor, KEMA Labs stands resolutely committed to future collaborations with diverse subcontractors and TenneT, continuing to pave the way for innovative and sustainable projects ahead.
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