The blade angle of normal wind turbines was fixed, thus rotating speed of the wind rotor will be increased rapidly. In this case, it will cause the blades break away from wind turbine body. Besides, it can also cause large current instantaneously for the whole system. According to these accidents, we adopt variable pitch technology and ABS system to actualize double protection of the system.

(1) The variable pitch wind turbines will automatically regulate the pitch when the actual wind speed is higher than the rated wind speed and ensure the rotating speed of wind rotor is the same as the rated wind speed.

(2) The self-developed ABS system can ensure automatic control for the status of brake on and brake off, thus ensuring safety working of wind turbines in super strong wind.