A wind generator’s electrical equipment can be divided into the generator, to be explained elsewhere, into the system for feeding electricity into the grid and the sensors for controlling and monitoring the generator.
The system for feeding electricity into the grid depends on the generator used: the majority of modern wind generators in the megawatt category use grid-connected asynchronous induction generators running at almost constant speed and direct connection to the grid. This means that rectifiers or inverters are not necessary.
In variable speed turbines with synchronous generators, the alternating current generated fluctuates constantly in frequency and quantity. In order for the electricity to be fed into the grid, it is converted into direct current using a rectifier, filtered and then converted back into alternating current using an inverter.
In both types of generator the voltage is then converted for connection to the level of the grid using a transformer and the wind generator and a measurement device are connected to the transmission grid.
Foundation and transformer for a wind turbine. ©Bundesverband WindEnergie e.V.
The nacelle has sensors or measurement devices that constantly record the following parameters: wind speed and wind direction, speed of the rotors and the generator, the ambient temperature and individual components, oil pressure, pitch and azimuth angle (yaw mechanism based on the wind direction) and electrical values, as well as vibrations or vibrations in the nacelle.
This data is used to control the generator, for example the direction of the wind is transmitted directly to the yaw mechanism or the data controls, when the generator is put into operation or switched off.
These sensors and the capture and analysis of these data monitor the wind generator providing the basis for good operational management.