Development of SAWT Wind Turbine
Shanghai Aeolus Windpower Technology Co., Ltd. (referred as “SAWT”) has been dedicated to the R&D of vertical axis wind turbine (referred as “VAWT”) for many years, and has experienced several stages of development, as the theoretical arithmetic, the wind tunnel experiments on aerodynamics, the prototype test, the clients’ feedback, the improvements and the mass production. Up till now, the SAWT product has been upgraded to the third generation.
The first generation VAWT:
After the R&D for two years, the calculations for over 10,000 hours and the wind tunnel experiments for more than 200 hours, the first generation VAWT was stereotyped. This generation is the lift-type wind turbine, which has employed the five-blade layout. Such design may not only let the wind mill have a good start performance in low wind speed surroundings, but also have a high wind utilization efficiency. The structure mostly employs the sustaining arms connecting the flanges and the main axis. At last, the main axis goes through the generator and connects directly to the base. This structure could pass the weight of the whole wind mill directly to the tower, instead of the generator. Thus, the load on the generator would be largely decreased, so as to have a longer lifespan of the generator. The products with the capacity below 1kw use the dump load system for over speed control and the manual brake system to stop the wind turbine when the wind speed is over the maximum working wind speed. The products with the capacity above 1kw use the aerodynamic over speed control system. When the wind speed is over the rated wind speed, the wind mill would automatically adjust the rotating speed according to the aerodynamic, thus keep the maximum output. SAWT is the only company who owns this technology and we have applied the Independent Intellectual Property Rights for our technologies. Compared with the first generation VAWT, the first generation VAWT has the practical value and becomes the first vertical axis wind turbine product to be commercialized in the world.
The second generation VAWT:
After the sales for over two years, the SAWT vertical axis wind turbine has been exported to over 50 countries and areas around the world. At the same time, SAWT also received the feedbacks from the clients. Some reflected the problems existed in the product. Such as, the inconvenience to use the manual brake; some metal parts use low-quality coatings; very few product has the mechanical noise. Aiming at these problems, SAWT has made an intensive study and proposed the corresponding solutions. Since 2009, SAWT brought out its third generation VAWT. The main improvements are as below:
1. Concerning the inconvenience of the manual brake system, the third generation product all employs the electromagnetic auto-brake system, which has a wider application, especially in the unattended areas.
2. For the products with the capacity below 1kw vertical axis wind turbine, the sustaining arms use the aluminum alloy die-casting technology, which not only improves the performance on anti-corrosion, but also increase the consistency of the products. For the products with the capacity over 1kw vertical axis wind turbine, the sustaining arms are going to use steel mixed with FRP (fiber-reinforced plastics) for better strength.
3. All the second generation vertical axis wind turbine has employed the integrated design for the generator and the main axis. Such design would increase the weight of the generator, but could thoroughly eliminate the mechanical noise; meanwhile, the reliability of the whole system has been increased.