How is motor power computed in MC Workbench projects?

Hi, I developed a project for a 1Hp PMSM motor with FOC algorithm. Expecially when running at low speed motor power given by MPM_GetAvrgElMotorPowerW() function is about 20% more than the real power. Hand computation based on RPM, Ke, Iuvw gives instead a good match with measured power. I cheched phase currents and are nearly perfect sinoidal signals and the motor run very smoothly, so I don't understand what can be the source of power mismatch. Thank you in advance.

Claudio Simeone