Field Weakening and other methods for increasing speed

Field Weakening changes the motor constant by decreasing Ke allowing for a little more speed. Other methods like increasing the dc bus voltage, tuning for sufficient current loop bandwidth, and turning off circular limits are much easier than using gain scheduling to adjust phase advance to get some field weakening. I have used this method in high speed spindle applications, in addition to estimated sinusoidal, to eak out a little more speed.