New Trends in Energy Efficient Electrical Machines

Today high efficiency electrical machines are a new and mandatory trend in the motor production in Europe and United States of America. Lately there are developed also higher efficiency classes as IE4 (Super Premium Efficiency) and IE5 (Ultra-Premium Efficiency). It is well known that IE4 electrical motors are available on the market and IE5 machines are taken into account by several big producers. Efficiency upgrade of the motors has very good consequences on the environmental problems. The efficiency classes (IE1-IE4) are described in the international standard IEC 60034-30. Line-start permanent magnet machines and Squirrel Cage induction motors can be upgraded, in order to have a bigger efficiency, according to IE4 specifications. In the case of variable speed machines variable reluctance synchronous motors are also included in the efficiency class IE4. In order to improve a motor to comply with the IE5 efficiency NdFeB or Ferrite magnets should be used.