Inherent Difference in Saliency for Generators with Different PM Materials

Table 1

Properties for different PM materials at 20°C. Data for NdFeB are taken from [2]. Data for ferrites are taken from a supplier (E-magnets UK). Costs are taken from [2] and have been updated by using the current metal price. The Y30 is used in the machine presented here. The Y40 is included for reference.

Property	NdFeB (N40H)	Ferrite (Y30)	Ferrite (Y40)
Remanence, Br (T)	1.29	0.38	0.45
Normal coercivity, Hc, (kA/m)	915	240	342
Intrinsic coercivity, Hci (kA/m)	1353	245	350
Energy product (kJ/m^3)	318	28.3	39.7
Density (kg/m^3)	7700	4700	5000
Energy density (J/kg)	41.3	6.0	7.9
Relative required mass	1	6.9	5.2
PM cost (EUR/kg)	29	1	1
Relative magnetic energy cost per generator	1	0.24	0.18