Direct coupled M/G sets
Our main range of frequency conversion is achieved by directly coupling the motor shaft to the generator shaft using a mechanical coupling, and adjusting the speed of the drive motor to vary the rotational speed of the generator, thus varying the output frequency. An adjustable speed electronic drive (ASD), also called a variable speed drive (VFD), is used for this purpose, instead of a conventional motor starter. This method also allows for the parallel operation of multiple frequency converters, using the ASD units to synchronize the outputs of the multiple motor generator sets. Power up to 2000kVA.
Common shaft M/G sets
The most sophisticated and precise rotary frequency converter is a synchronous motor frequency converter – synchronous generator converter, both units made on a single common shaft. In this case, the frequency change is made by winding the motor with a different number of electrical poles than the generator. For example, a 12-pole motor and 10-pole generator will yield a 60 Hz to 50 Hz conversion. Using a synchronous drive motor allows the rotational frequency to be “exact”, that is, as precise as the electric utility grid. Manufacturing the converter on a common shaft also increases the reliability of the unit. Power up to 1000kVA.
Belt coupled M/G sets
Drekan-Group manufactures and supplies belt-coupled motor generator sets (rotary frequency converters) to all industries requiring the test or operation of electrical equipment using power characteristics (AC frequency) that are not available on the local power grid. Belt coupling is the simplest and least expensive method of coupling the drive motor to the generator, using drive belts and pulleys. This method not only transfers the energy from motor to generator, but also is used to change the frequency by pulley ratios. The motor generator set converts frequencies of 50Hz, 60Hz, and 400Hz. Power up to 250kVA.
AC to DC converter
Drekan Group can provide direct coupled M/G sets base on an AC motor driving a DC generator, the voltage can easily be adjusted to the speed and/or excitation of the DC machine. Largely used in the past to powered the larger DC machine (ward leonard concept), this type of converter can still find many applications to supply high power DC sources free of power electronics. Power up to 1000kW.
