Field-oriented asynchronous pulsewidth modulation for high performance AC machine drives operating at low switching frequency

A novel pulsewidth-modulation technique is reported that is based on the prediction of the trajectory patterns which the stator current vector describes in a field-oriented coordinate system. The method limits only the error of the torque-producing current component while exerting no constraint on the harmonics of the field-producing current. High dynamic performance and minimum switching frequency is achieved with the help of precalculated memory data, permitting implementation in low-cost hardware.<>