Study On Permanent Magnet Brushless Dual-Rotor Wind Turbine

With the world energy crisis and people's increased awareness of environmental protection, people all around the world began to focus on new energy research and application. In all the new renewable energy sources, wind energy with the advantage of its pollution-free, wide range and high efficiency is fastest growing, currently becoming the most promising new energy sources.Firstly the structure and principle of the permanent magnet brushless dual-rotor generator are deduced in accordance with the structure and principle of a cascade brushless double-fed machine in the paper. It is discussed constraint relation among frequency of permanent magnet brushless dual-rotor generator, frequency of asynchronous generator and generator speed. It is concluded that this generator has the variable speed constant frequency characteristic and it is suitable for wind turbine. The paper shows improvement of Betz' Law detailed and deduces the aerodynamic characteristics of the wind turbine with double rotors. The wind turbine with double rotors can raise the utilization rate of wind energy. According to the characteristic of a permanent magnet brushless dual-rotor wind turbine, this paper analyzes the exciter with the permanent magnet external rotor that is connected to the auxiliary rotor rotated in different speed. The slip power that the exciter generated may offer to the generator connected to the main rotor. It also analyzes when the main rotor speed is variable, by adjusting auxiliary rotor speed, the generator can supply constant frequency (50Hz) AC power. This establishes the theory basis for further research and practice on this type machine. In the end, this paper analyzes the influence between wind turbine generators and the grid integration technology in brief. Base on the wind turbine generator technology, this paper presents the concept on the system wind power technology. The technology except power quality and LVRT when wind turbine generators are integrated into the electricity grid system the wind power forecast and power energy storage devices are also to be required. So, we can see the advantage of this type of wind turbine generator on the concept of the system wind power technology.