Investigations on permanent magnetic materials to be used in explosion-protected permanent magnet synchronous machines

Due to the high energy-saving potential (or energy efficiency) during full or in the partial-load range, the manufacturers desire to use a permanent magnet synchronous machine also in potentially explosive atmospheres. The safe operation of a permanent magnet synchronous machine (PMSM) in potentially explosive atmospheric environments requires a better understating of temperature build-up on the the permanent magnet rotor and the effect of temperature on the surface or interior of the permanent magnet. The magnetic properties of neodymium iron boron (NdFeB) magnets need to be considered properly while designing, manufacturing and operating the machines. The long-term effect of NdFeB-based magnets at high temperatures and their corrosion behavior have to be studied due to the irreversible loss of magnetic properties.