Estimation of rotor operational characteristics for a wind turbine

An arrangement for estimation of rotor operational characteristics, including rotor speed, rotor azimuth and rotation direction, of a rotating rotor of a wind turbine, the arrangement comprising:

• multiple proximity sensors;
• and
• a processor, wherein the processor is configured:
• to measure pulse rising edge time and pulse falling edge time of pulses generated by each of multiple proximity sensors originating from each of multiple detection targets arranged on the rotor;
• to estimate values of parameters of the positioning and detection range of at least one sensor based on the measured pulse rising edge times and pulse falling edge times, and
• to estimate rotor operational characteristics, including a rotor speed and a rotor azimuth and a rotation direction, based on the measured pulse rising edge times and pulse falling edge times and the estimated values of parameters associated with the sensors,
• wherein estimating a rotation direction comprises detecting which respective sensor of the multiple proximity sensors first detects a target,
• wherein estimating the rotor speed comprises mapping angular distances associated with pulses to corresponding time measurements, and
• wherein estimating the rotor azimuth is based on a previously calibrated rotor azimuth position increased or decreased, depending on estimated rotation direction, by an integral of the estimated rotor speed over the difference.

A wind turbine, comprising:

• a rotor in which plural rotor blades are mounted, and
• an arrangement, the arrangement having multiple proximity sensors and a processor configured to:
• measure pulse rising edge time and pulse falling edge time of pulses generated by each of the multiple proximity sensors originating from each of multiple detection targets arranged on the rotor;
• estimate values of parameters of the positioning and detection range of at least one sensor based on the measured pulse rising edge times and pulse falling edge times, and
• estimate rotor operational characteristics, including a rotor speed and a rotor azimuth and a rotation direction, based on the measured pulse rising edge times and pulse falling edge times and the estimated values of parameters associated with the sensors,
• wherein estimating a rotation direction comprises detecting which respective sensor of the multiple proximity sensors first detects a target,
• wherein estimating the rotor speed comprises mapping angular distances associated with pulses to corresponding time measurements, and
• wherein estimating the rotor azimuth is based on a previously calibrated rotor azimuth position increased or decreased, depending on estimated rotation direction, by an integral of the estimated rotor speed over the difference.