Goldwind has achieved grid connection of a low-frequency wind turbine designed transmit alternate current (AC) power over long distances.
The Chinese turbine maker said this latest stage of the Taizhou 35kV Flexible Low-frequency Transmission Demonstration Project on the Dachen Islands in Zhejiang province, marks a “first milestone”.
Goldwind said it is the first time a low-frequency permanent magnet direct drive (PMDD) wind turbine that continuously transmits AC power via low frequencies over distances, ranging from 80-200 km, has been grid connected.
In a statement, the chief officer at State Grid Zhejiang Electric Power Company said: “The Taizhou Project serves as an important test case for future R&D of 10-megawatt and above wind turbines to transmit via low-frequency – further unlocking the potential for far more power to cross greater distances and with more economic efficiency.”
The Taizhou Project is the first demonstration project of flexible low-frequency transmission in China, said Goldwind.
The project couples an island-based low-frequency connection with two “sizable” wind turbines that then integrates via a series of grid transmission capabilities in order to build a network of sea-island-land connections.
“Goldwind’s latest 20Hz low-frequency AC power from its wind turbine aims to solve a number of limiting factors for offshore to land wind projects – charging reactive power, power loss via underwater cable systems, and the high cost for investment and O&M – that occur in either power frequency-based AC power transmission or DC power transmission.
“The Goldwind PMDD machines coupled with low-frequency smart technology makes them an ideal solution for large-scale offshore wind power with long-distance transmission,” said Aisi Kaer, lead engineer on the project.
Goldwind said further development and commercial applications of low-frequency wind turbines will play an important role in mass development of long distance offshore wind power projects as well as medium- and long-distance power transmission which are commonly found across long-stretches of deserts, like that of the Gobi Desert.