
4-6 Power Electronics and Motor Drives
In the stator, both the stator joule losses,
, and the iron losses,
, are active. e
dierence between the absorbed electrical power and the stator losses is the power transmitted by the
stator to the rotor P
T
P P P P
T s js fe
= − −
(4.18)
With reference to the single phase equivalent circuit of Figure 4.4, the transmitted power has to be
attributed to the resistance R
r
/s and the following relation can be written as
P
R
I
T
r
r
= 3
2
(4.19)
Since, from the physical point of view, the rotor winding has an actual resistance, R
r
, the rotor joule
losses active in the rotor are
P