| Abstract |
In this paper it is shown that any
ux estimator|not
just the \current model"|can be implemented using
indirect eld orientation (IFO). We use the \voltage
model" as working example. A generalized slip rela-
tion, replacing the standard slip relation, results. Im-
plementation of the \voltage model" using indirect
vs. direct eld orientation (DFO) is compared with
respect to computational complexity. While DFO re-
quires about 40% less computations, it is shown that
the computational overhead is, when using a mod-
ern xed-point digital signal processor, insigni cant
in both cases. The bene ts of implementing the
\voltage model" in IFO are twofold, and both con-
cern sensorless control. First, the \voltage model"
can be successfully used also at low speeds, avoid-
ing transition to the \current model," which would
require speed measurement. Second, a very simple
method for speed estimation, which does not require
a dynamic estimator such as an observer, can be employed. |
