At present, the variable pitch mechanism of wind turbines is basically divided into: electrically controlled variable pitch and centrifugal force variable pitch.

The electronically controlled pitch control mode is passive pitch control, with a controller system to detect generator voltage and current, and equipment such as motors, hydraulics, and push rods are used to achieve blade pitch control. The pitch mechanism requires auxiliary power supply, including backup power sources such as batteries, and the design is complex, therefore the cost is relatively high. Due to the complexity of mechanical design, the failure rate is also high during operation.

Centrifugal force variable pitch is a structure where an iron flying rod is installed at the root of the blade, and the centrifugal force generated by the impeller speed is used to change the blade angle. This structure is a purely mechanical action variable pitch. The use of centrifugal force variable pitch can only be used for high-speed wind turbines, and usually low-speed operation of wind turbines is not conducive to the system. Furthermore, centrifugal pitch control is a reverse pitch control mode with minimal angle variation.

Our company excludes the above two types of variable pitch structures and adopts generator power variable pitch technology:

This technology has been applied for a national invention patent.

The main advantages of this technology are:

1. The main components are made of imported materials, and the pitch system can operate 300000 times without pressure drop, with a pressure drop of 10% for 500000 times. 20% pressure drop after 1 million cycles. Based on 300000 calculations, the service life exceeds 30 years in strong wind weather operation.

2. Active real-time pitch control does not require external support, such as auxiliary motors, hydraulic systems, push rods, screw rods, and other external forces to force pitch control.

3. Free to face the wind, with zero fault in the downwind direction. There is no need for support from yaw motors, brake pads, wind direction indicators, anemometers, etc. to support the yaw system, and due to excessive auxiliary equipment and accessories, the failure rate is high.

4. The entire system does not require external power supply, fans, controller inverters do not consume power, and backup power and batteries are not required for control.

5. The unit braking system is soft braking, which will cause the blades to pitch and stop. Do not adopt forced braking mode.

6. In order to prevent cable twisting, a high-end conductive slip ring is equipped. The unit model has 3-6 circuit outputs, each with an independent slip ring, which will not cause circuit short circuiting, thus achieving a slip ring service life of more than 10 years. The transmission cable of this unit only has 3-6 channels, so there is no need for automatic unwinding. (Automatic cable termination failure can cause cable twisting)