Sensorless Starting of Wound Rotor Synchronous Machines

The sensorless operation of wound rotor synchronous machines (WRSM) must meet several requirements. The most important to be mentioned is how to insure starting at full load and then operating at low speed in the presence of magnetic saturation. This work presents a solution for high power machines by combining a method of rotor location by high frequency injection and then starting it with a Phase Locked Loop (PLL) type solution. It should be noted that the location of the rotor leaves an indeterminacy of pi on the electrical position that needs to be resolved. Initial experimental tests for rotor location confirm simulations and show how the scheduling of the two methods can solve the problem.