Variable Frequency Drives (VFDs) play a crucial role in the operation of cranes and hoists. They are used to precisely control the speed and torque of electric motors, thereby enhancing operational efficiency and control accuracy.

On March 16, with the final cable strand accurately positioned, the main cable pulling work for Fenglin Special Bridge on the Xingyi Belt Expressway was successfully completed. This marked a significant milestone in the bridge’s superstructure construction and laid a solid foundation for achieving the goal of full completion by the end of 2020.

The high-performance, high-power variable frequency drives (VFDs) provided by V&T Power played an important role in ensuring the smooth progress of the bridge’s main cable installation due to their stable performance and excellent reliability.

Fenglin Special Bridge is China’s first large-span steel-concrete composite beam suspension bridge built in mountainous terrain. The vertical height from the bridge deck to the valley floor reaches 364.2 meters—equivalent to approximately 120 stories. The lifting of the prefabricated central crossbeam at Tower No. 4, weighing up to 1,470 tons, set a world record for the heaviest prefabricated concrete component hoisting in mountain canyon bridge construction.

Main cable construction is one of the most critical and technically challenging processes in the building of Fenglin Bridge, as it forms the primary load-bearing system of a suspension bridge. The bridge has two main cables—one on each side—each approximately 971 meters long, with a total weight of 4,131 tons. Each single cable consists of 131 strands (including 4 backstays), and each strand is made up of 91 zinc-aluminum-magnesium-coated steel wires with a diameter of 5.45 mm. The maximum weight of a single cable strand is about 16.4 tons.

The winch systems installed on both sides of the bridge have extremely high requirements for the performance, stability, and reliability of the VFDs. The V&T V6-H torque vector control VFD performed exceptionally well, playing a key role in the main cable pulling process. Its advanced technology and product stability have received high praise and recognition from users.

During equipment commissioning, Ma, a V&T technical engineer, had to walk across the “catwalk” on the bridge. He said: “Standing over 360 meters above the valley floor just thinking about it makes my legs weak. This time really pushed my fear of heights to the limit. Walking on the catwalk feels like walking through clouds—nervous yet incredibly impressive. I deeply admire the hard work, selflessness, and perseverance of the bridge builders, who embody the spirit of the ‘Iron Army.’”

Since the start of construction, Fenglin Special Bridge has been widely covered by major media outlets including CCTV's *News Broadcast*, *Morning News*, *Great Transportation of China*, Xinhua News Agency, People's Daily Online, and local news platforms.

Over the years, V&T has continued to develop and manufacture high-performance, high-quality products such as VFDs, contributing to major infrastructure projects across China and supporting the development of the nation’s transportation network.