Wind Turbine Pitch Control

Typically a wind turbine pitch control system is built with a controller, pitch control mechanisms, a backup power supply, and a feedback module monitoring generator 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 made up of rotary encoders, gate drivers, IGBT modules and servo motors. 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 gate drivers, IGBT modules of these mechanisms drive their associated motors to change blade incidence. Meanwhile, the real-time pitch information is sent back to controller by rotary encoders. Feedback module is composed of voltage sensor and current sensor which the collect voltage and current signals from generator and send to controller. In order to feather the blades in the event of an emergency situation, backup power is needed. Backup power can be implemented with batteries, ultra-capacitors, or even a hybrid solution offering the best of both options.

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