Indirect testing to determine losses of high speed synchronous permanent magnets motors

The limitations imposed by manufacturer's power supply as well as load and cooling equipment make difficult to qualify the efficiency of high speed PMs machines. In addition, indirect methods outlined in IEEE, IEC and NEMA standards exclude considerations of permanent magnet synchronous machines. Besides some classical tests, we propose an indirect testing to evaluate the losses and then the efficiency of the high speed permanent magnet motor fed by a VFD. The testing needs only a VFD, the test machine and a LC filter.