High-speed performance of variable-reluctance stepmotors

An analytical study is carried out with the aid of Blondel diagrams in order to identify the key parameters responsible for the performance limitations in a unipolar step-motor drive. It is shown that the fundamental component of the excitation voltage waveform and the total phase resistance govern the maximum output-power capability of the drive. Predicted and experimental results are presented for a multistack motor which demonstrated not only the validity of the theory but also highlights the effectiveness of using Blondel diagrams for stepping motor analysis