Alternative Energy Solutions - Wind Turbine Pitch Control
Wind Turbine pitch control system is usually built using a controller to employ the pitch control mechanisms and a feedback module for monitoring the output power. High performance MCUs or DSCs are often selected as the controllers of pitch control systems. They are responsible for giving instructions to pitch control mechanisms based on real-time wind speed, preset power rating, pitch information, and output power signal of generator. Pitch control mechanisms are commonly comprised of a motor and a motor driver. Each motor blade needs a single control mechanism, which means three mechanisms in total are required.
After the instructions given by controller are received, the motor drivers drive their associated motors to change blade incidence. Meanwhile, the real-time pitch information is sent back to controller. The feedback module, composed of voltage and current sensors, forms the feedback loop which feeds the voltage and current signals from the sensors back to the controller.
When wind speed is not higher than the rated speed, the blade incidence stay near the angle 0° (highest power point). This is similar to that of a generator with constant pitch, generating an output power that changes along with wind speed. At higher wind speeds, the pitch control mechanism changes blade incidence so that the output power of generator is within the allowed range.