Mechatronics comprises basically two systems: pitch system and yaw system.
The pitch system controls the rotor speed to given set points. It is used as aerodynamic brake in addition to the mechanical brake. The pitch system operates as follows: Below the nominal wind speed, the pitch angle is set to a defined blade angle. Once the wind speed reaches nominal speed, the pitch system starts to adjust the pitch angle to limit the rotor speed of the WTG to nominal rotor speed. The optimal energy output is reached at nominal rotor speed.
Each blade has its own pitch drive system consisting of an electrical motor with gear box driven by a frequency converter, a battery backup system and a forced ventilation system. The Suzlon Control System (SCS) transmits the required set points for the blade position. Each blade is controlled separately and independently. The pitch drive motors are located inside the hub.
The yaw system is used to ensure an optimal alignment of the nacelle/rotor to the wind. The wind direction is measured by two independent wind sensors at the equipment frame on the nacelle roof. The sensors transmit the measured values to the SCS. The yawing is performed by the electromechanical yaw drives, which are activated as soon as the SCS recognises a certain predefined difference between the rotor axis and the current wind direction.