Hong Kong-Zhuhai-Macao bridge, China

The ultra-large sea crossing Hong Kong - Zuhai - Macao bridge, passing through Lingding bay, is the longest bridge-tunnel complex in the world. This bridge connects Hong Kong, Macao with Zuhai in Guangdong province. It is divided in 3 parts - offshore bridge, undersea tunnel and artificial islands.

Air ventilation is a critical system for the operation of the 6.7 km long tunnel, running at the depths up to 48 m undersea. For this, multiple jet fans are mounted on the tunnel roof, which handles airflow in the tunnel and exudes vehicle emissions. This ventilation system requires power quality solutions for effective functioning.

To address this demand, Hitachi Energy has installed open rack capacitor bank QBank and metal enclosed capacitor bank ABBACUS in two undersea substations, located in the East and West artificial islands respectively, to compensate reactive power for jet fans and other equipment in the electrical system of the subsea tunnel. These installations improve power efficiency and ensure high-quality power transmission and equipment up-time.