Hello, I’m currently designing a small scale Wind turbine using a direct drive with a permanent magnet syncronous generator (no gearbox) and the mechanical equation that’s in the PLECS documentation is:

d/dt (wm) = 1/J (Te - Fwm - Tm) (1)where F is friction, wm is the mechanical speed and, the electromagnetic torque (Te) is positive and the mechanical torque ™ negative. In the literature I’ve read this equation is used with Te negative and Tm positive, since it is used as a generator.

d/dt (wm) = 1/J (Tm - Fwm - Te) (2)My question is it okay to change this terms and using the equation with the rest of my system? or should I keep just as PLECS documentation? is it worth to mention that in Mathcad 15 i used (2) with my calculations and the results i get are correct but the moment i go to simulate with PLECS the system just doesn’t work. Thanks for reading this far.