The ALSPA MD2000 frequency inverter type series makes a major contribution towards reducing the reactive power on the mains network and therefore limits the investment costs for cables, switchgear units, filters and transformers. ALSPA MD2000 Active Front Ends (AFE) allow for 4-quadrant operation of drives by using the same reliable components as the motor pulse inverters in mains pulse inverters as well. Besides standard applications such as pumps and fans, the field of wind driven generators, test bench drives or lifts is an example of use of the ALSPA MD2000 type series for motor power ratings from 15kW up to 4500kW. In the lower power range from 0.75kW, the type series is completed by the ALSPA MV1000 frequency inverter.