I am focusing on the losses generation in PMSMs and still have some doubts about the role of a low power factor.
For the analysis, I consider a three-phase PMSM controlled with Field Oriented Control (FOC), where \$I_{d}\$ is maintained equal to 0 to minimize resistive losses. Considering to impose a torque \$T\$, \$I_{q}\$ follows the relation: $$I_{q} = \frac{T}{k_{t}}$$ Resistive losses in the motor are equal to: $$P_{loss} = \frac{3}{2}R_s\sqrt{I_d^2+I_q^2} = \frac{3}{2}R_s\sqrt{I_q^2}$$ How does the power factor affect losses if \$I_{q}\$ is a fixed value imposed by \$T\$ and Joule loss depends only on \$I_{q}\$? Is it influencing other types of losses (es. iron losses)?
I know that \$P = V I cosϕ\$ and to get the same P with a low power factor I need to supply more current (or voltage), but from the previous equation I do not understand what am I missing.
