Abstract – SCADA data in wind farms are normally not enough to discover the inner behaviour of all the subsystems in a wind turbine. This paper shows what we learned in the design of a specific data logger to collect data in the field for long periods (months) and their processing.

The data gathering had time resolution enough to characterize the short term variations of the wind and its relation to rotational speed in the generator axis, the energy produced, pitch evolution, etc.

This experience was used to find real functional parameters for each of the subsystems (pitch/hub, brakes, nacelle’s orientation, etc) of a stall machine with dual generator. Those parameters were key for the development of a Simulator/Trainer for that wind turbine.

It is also the first step for the design of a complete condition monitoring system specialized for wind turbines.

Index Terms – wind turbine, data logger, condition monitoring.