Alternating Current Waveform Control Method for BLDCMs Using Repetitive Control Techniques

We propose a new alternating current (AC) waveform control method for brushless DC motors (BLDCMs) using repetitive control (RC) techniques. It is totally different from the very popular current control method used in fields oriented control (FOC) (or vector control methods) of BLDCMs, because instead convert alternating current (AC) into direct current (DC) at the FOC, the proposed method controls the alternating current waveform directly using repetitive control techniques for each phase. The proposed current control method is based on the internal model principle, and repetitive controllers are well known for containing the internal model. In addition, the repetitive control techniques have many excellent characteristics such as disturbance elimination. Such a control method proved an alternative way in control of BLDCM, especially when some things need to be considered such as 3 phase asymmetry, non-sine wave drive and etc.