1. Systems of 10kw-50kw take downwind structure and do not have frequently mechanical controls. The wind turbine systems adjust automatically according to the different wind direction and wind force. The control systems of wind pressure which powers the variable pitch are well used in variable pitch. When the wind turns stronger and stronger and even over the rated wind speed, the blades adjust themselves to reasonable angles to meet the present wind speed and the max angle is 90°. Then the whole system protects itself by this way. For 20kw, 30kw and 50kw, manpower brake apparatus are used. When the wind is very strong or repairing the system, the manpower brake apparatus makes double safety of the whole system. Closed collecting rings which is intense current and brushes are used in transmission of the power generating by wind. Its strong point is making the cable work normally when the wind directions are unstable, no twist.
Kinds of variable pitch are, adjusting the blades direction according to the wind speed and the max angle is 90°.
We abandon the technique of worm and gear, hydraulic technology and gear rotary. Out loading part: when the battery is full, the box of out loading will use up the extra power and hen the blades will stop under the electric controls of variable propeller pitch
