Mesurement of magnetic properties for conditions of use and how to get there from the comfort of the laboratory

The magnetic properties of soft magnetic materials need to be measured for conditions that represent how they are used in order to achieve more reliable devices and meet target specifications. For the purchase and sale of magnetic materials written IEC standards exist and provide the necessary framework. For AC measurements the IEC standards require waveforms to be sinusoidal as this allows comparable measurements. In practise, such ideal waveform conditions would not occur and more representative conditions need to be used. Modelling of electrical machines requires reliable data if the performance specification is to be met without too many failed prototypes. As well as waveform conditions, other operational parameters are temperature and stress. Measurement techniques that can generate the conditions of use are needed and work to establish these is presented here. Measurements of specific total loss are reported at operating frequencies and temperatures, as well as the effect of stress on DC properties