Novel Recuperation Capability for Variable Speed Drives

Efficiency and recuperation capabilities of modern electrical drives have become very important features within variable speed drive applications. Regenerative electrical drives are therefore usually equipped with cost extensive pulsed active front end topologies for the recuperation mode. Contrarily, the much cheaper fundamental frequency switched front end is used. It has no electrolytic capacitor with its limiting effect on the operating temperature and lifetime. Additionally to the converter topology, the used squirrel cage induction or alternatively the permanent magnet based machine shows different advantages with respect to the efficiency-torque characteristic within variable speed drives.