Electrical engineering and drives in the globalisation age and their contribution to sustainable development and knowledge-based society

Human beings just entered the globalization age, sustainable development and knowledge-based society are knocking at the door. Industry-academia link provides a good chance to be active players in the European Research Area. One example is the continuous casting where heavy and burning liquid steel is pouring out from a vessel traveling together with the crane and driven by induction motors. The motors are controlled by a motion computer station and a central computer unit which is settled down on the ground. In the city of Miskolc, North Hungary in the boiler house of a heating plant one pump is driven by an induction motor of 600 kilowatt fed by an inverter. Some weeks after the assembly roller bearings were damaged. Mechanical resonance appeared around 10 kHz, the self-frequency of the motor was also 10 kHz. Based on hypothesis and measurement the switching frequency of the inverter had an increase up to 12 kHz and resonances were eliminated