Encoders

Many measuring and positioning tasks must be solved in wind turbines: in addition to yaw control of the nacelle through azimuth drives, the tilt angle of the rotor blades must be monitored and – if necessary – adjusted by means of pitch control systems. On top of that, speed control can be complicated due to the demanding environment. POSITAL, a provider of absolute encoders and optical measuring systems, offers an extensive one-stop range of sensors that withstand even extreme environmental conditions. Absolute encoders always ensure reliable positioning. Unlike incremental systems, absolute encoders never require a reference run, even after power failures. Thereby, they increase the safety and efficiency of wind power plants. Their superior positioning precision also helps increase economic efficiency. The company's absolute encoders are available with a wide range of fieldbus, Ethernet, and serial interfaces as well as many different mechanical models, allowing for easy integration into machines and plants. They have already proven themselves in many wind energy applications. For example, optical absolute encoders with a maximum resolution of 16-bit are used in absolute position measurement for azimuth control systems that adjust the nacelle depending on the wind direction. With up to 300N shaft loading capacity, these are robust enough to handle high wind forces. Magnetic absolute encoders are used to precisely determine angles for the pitch control system that dynamically controls the angle of the rotor blades. Based on an innovative magnetic technology without gears or batteries, they are enclosed in durable, salt-spray resistant IP69K housings. They can be installed in limited spaces and are completely wear-free. The company's optical systems include a sensor, with a <1% measuring accuracy, that focuses on the rotating hub and analyzes the motion. Requiring no mechanical connection with moving parts, they are suited to non-contact monitoring of the rotational speed in wind turbines.