AUTHOR : Ji-Young Lee, Sang-Ho Lee, Geun-Ho Lee, and Jung-Pyo Hong
ORGANIZATION : International Compumag Society
JOURNAL : COMPUMAG
YEAR : 2005.6.26
VOL : I
ISSUE :
PAGE : 174 ~ 175
These days, interior permanent magnet synchronous
motors (IPMSM) are very attractive for application to the
systems required high power density such as hybrid vehicles
and compressors. As those systems become more compact,
the electric motors are getting highly saturated. It is, therefore,
naturally required to consider the magnetic nonlinearity when
the machines are designed or analyzed.
Although there are several papers for the parameter
determination in equivalent circuits considering iron loss [1,
2], the parameters are obtained from measurement,
experimental equations, or electric linear equations. These
methods, however, can not be used in design process or can
not estimate the parameters accurately in saturated condition.
Therefore, this paper presents a method to calculate motor
parameters considering magnetic nonlinearity in IPMSM.
The motor characteristics are estimated by using equivalent
circuits, and some parameters, consisting the circuit and
affected magnetic saturation, are obtained by using finite
element analysis method (FEM). Permanent magnet flux,
resistance of stator iron loss, and d- and q-axis inductances
are the examples for the parameters. The other parameters
can be calculated by common equations [1].
Since the method about calculation of permanent magnet
flux is very fundamental in FEM [3], only the computation
methods about inductance and resistance of iron loss are
presented in this paper. It is evident that each method is not
very new. However, it is new challenge that the critical
parameters of equivalent circuit are calculated by FEM, and
the characteristics are estimated from the circuit. The
accuracy of the method is examined by the comparison of
calculated and measured results of an example IPMSM.