Siemens Energy has commissioned a power transmission system for the 8 MW offshore wind turbine installed at the Shantou Haojiang onshore industrial park as part a demo project by Shanghai Electric in China.
The system consists of a SF6 (sulfur hexafluoride)-free gas-insulated high-voltage switchgear (GIS), called 8VM1 Blue GIS, and a liquid-immersed distribution transformer with ester fluid.
The switchgear and transformer designs have been optimized to hold up under the hostile conditions of offshore applications and to keep the maintenance demand as low as possible, according to Siemens Energy.
The Siemens Gamesa 167-8 MW Direct Drive (DD) wind turbine was installed at the industrial park in January, with Shanghai Electric holding a license to manufacture, sell, and install Siemens Gamesa’s 8MW Direct Drive turbines in China.
The wind turbine marks the first implementation of Siemens Energy’s 66 kV technologies for wind turbine applications in China.
The 8VM1 Blue GIS was specifically developed to enable higher voltage levels in wind turbines. It utilizes vacuum interrupters for switching functions and “clean air” as the insulation medium (industrially purified air), representing an environmentally friendly alternative to the potentially climate-harming insulating gas SF6, Siemens Energy said.
“The growing power demand requires a new generation of wind power plants equipped with innovative technologies”, said Beatrix Natter, Executive Vice President Transmission at Siemens Energy. “Our SF6-free switchgear and our synthetic-ester transformer are contributing to the concept of an integrated clean energy solution. This demo project demonstrates true technology leadership and we are proud to be at the forefront with our sustainable product portfolio”.
The 8VM1 Blue GIS can be installed inside a wind tower or a transition piece, according to the company, as it features a compact and lightweight design adopted for wind turbine application.
The transformer of type FITformer REN was also developed to operate at a grid voltage level of 66 kV for wind turbine applications.
“The 8.8 MVA transformer is filled with ester biodegradable insulation fluid, an environmentally friendly and operationally safe alternative to conventional mineral oil. Its compact size and light weight allow the transformer to be installed inside the wind turbine’s nacelle”, Siemens Energy states.