Introduction to the direct-driven permanent magnet type wind turbine
　　The performance curve of the best combination of the direct-driven wind turbine permanent magnet generator and modularized converter system reveals high efficiency of electricity generation. The design characteristics include almost maintenance free complete equipments. Neither hydraulic systems nor emergency batteries are used. The availability of the equipment has been improved by reducing parts and components with the principle of not impairing major responsibilities. A highest degree of precision can be provided from the diagnosis and control system of the turbine which is connected directly with a piece of chip and other control chips of one turbine or the turbine of the entire wind field. Generally, the operation of this system can be controlled conveniently by SPS or a computer, for a complete intelligent distributed mode is used by built-in ways. SETEC variable pulp system possesses features of high quality and affordable price. Since 1996, variable pulp server driver and variable pulp had been manufactured, which makes the maintenance free AC driver to be used at the beginning. IGBT converter of 100 times belongs to an important link of motor operation. Power supply control procedure used to improve efficiency has also been developed and used since 1998. The expectable special effect from SETEC design is that the manufacture cost would become extreme low. Although the price is the cheapest one, we also have advantages in technology and market comparing with products of the same type. Cost optimization of the complete machine can also be realized in this way, for our partners can manufacture parts by themselves as much as possible, especially for TV whose production cost is very little comparing with other known products of the same type and which is suitable to be manufactured in batches.