The output of wind turbine generators is increasing continuously and is calling for the use of new technologies. Consequently, these wind turbine generators themselves and their components have to be designed for greater outputs.

Moeller is contributing to this increase in output with the use of vacuum technology in its contactors. Their vacuum tubes are ideal for switching high voltages up to 1000 V as arcs are not produced and no escaping gases occur during switching. This means that a switch cabinet can be designed with narrow spaces between components. Unlike conventional air contactors, which require greater mechanical forces to close the contacts for the higher ratings, an intelligent control electronics unit is used for less destructive switching in the vacuum tubes. This reduces the mechanical forces and drive output required, whilst increasing the lifespan of the contactors for operation over several decades.

From a rated current of 1600 A the current is distributed on two vacuum tubes per pole. The integrated release electronics ensures the absolutely synchronous switching of all contactors, thus relieving the user of otherwise unavoidable control routines from the PLC program.

In order to control the generated power reliably, wind turbine generators over two megawatts often require medium-voltage switchboard systems instead of low-voltage systems. This involves considerably higher costs as a result. The compactly designed Moeller contactors are available for up to a rated operational current of 2200A. The 2500 A rating class will be added to the series in future, thus allowing the use of inexpensive low-voltage power distribution systems in increasingly more powerful wind turbines.