Centrifugal fan system has brought two advantages in reducing mechanical transmission. On the one hand, the introduction of variable speed drive mode can increase the rated power of centrifugal fan for a given size gearbox. On the other hand, for a given rated power fan, the introduction of variable speed drive can reduce the size of the gearbox.
The cost of constant-speed fans with low rated power in gearboxes and other transmission devices is relatively low, while the cost of winding generators in variable-speed wind turbines is relatively high. Therefore, in the system whether to use variable speed drive mode should consider the size of the fan energy level.
When the energy level is higher than 1mw, the variable speed wind power generation system can show its superiority. The use of variable speed fan can also effectively reduce the noise of the fan. Under the condition of low wind speed, the speed of fan is very low, which greatly reduces the generation of noise. When the wind speed increases, the increase of wind noise masking the increase of fan noise caused by the increase of fan speed.
The variable-speed wind power generation system retracts the electric energy to the power grid, which can weaken the influence of the instantaneous change on the system due to the wind and mechanical system to a certain extent. When the wind speed decreases, the rotational speed of the centrifugal fan system also decreases, and the inertial energy storage part can release the stored energy.