Monitoring, Control and Communications



Once the wind turbines are turning and generating electricity, the issue becomes how does that electricity get back into the common grid?  While self-contained units do exist for certain applications, the bulk of today’s wind power farms are in place to augment the supply of electricity to everyone, cleanly and effectively. This can be complicated by the fact that many sites are in remote and difficult to reach locations.  In view of this, the ability of individual units to communicate with themselves, with the other turbines in the farm, and with the larger power system is doubly important.


Communicating With the Outside World

The controllers communicate with the owner or operator of the wind turbine via a communications link, for example, sending alarms or requests for service over a telephone or radio link.  It is also possible to call the wind turbine to collect statistics and check its present status.   In wind farms one of the turbines will usually be equipped with a PC from which it is possible to control and collect data from the other wind turbines on the farm.  The computer can be called over a telephone or a radio link.


Internal Communications

There is usually a controller both at the bottom of the tower and in the nacelle.  On recent wind turbine models, the communication between the controllers is usually done using fibre optics.  On some recent models there is a third controller placed in the hub of the rotor.  It usually communicates with the nacelle unit using serial communications through a copper cable connected with slip rings and brushes on the main shaft.


What is Monitored?

It is possible to monitor or set somewhere between 100 and 500 parameter values in a modern wind turbine.  The controller may, for example, check the rotational speed of the rotor, the generator, its voltage and current.   In addition, lightning strikes and their charge may be registered.  Also measurements may be made of outside air temperature, temperature in the electronic cabinets, oil temperature in the gearbox, the temperature of the generator windings, the temperature in the gearbox bearings, hydraulic pressure, the pitch angle of each rotor blade, the yaw angle, the number of power cable twists, wind direction, wind speed, and frequency of vibrations in the nacelle and the rotor blades, and so forth.