This paper presents a dynamic method that derives the magnetic model of permanent magnet synchronous machines. The method uses the moment of inertia of the rotating parts to limit the speed dynamics while specific stator winding currents accelerate and brake the machine. Measurements of the rotor position and the phase voltages give the voltages in the dq frame and the rotational frequency, which in turn yield the magnetic model. In addition to the magnetic model, the method also provides the dq inductances and the resistance of the stator windings. Results from the method are compared to an established test method and finite-element simulations with excellent match. Furthermore, the results show that the method is robust to changes of the temperature in the stator windings of the machine.