Permanent magnet motors are widely utilized in various industries due to their high efficiency and superior torque characteristics. However, these motors exhibit significant efficiency losses at high speeds, which limits their performance. To overcome this challenge, variable flux motors (VFMs) have recently been introduced as a high-speed alternative to permanent magnet motors. While extensive research has focused on the rotor design of VFMs, less emphasis has been placed on their drive and control systems, particularly in the deep flux-weakening region. The adjustable magnetic flux in VFMs necessitates a redesign of conventional control strategies to ensure optimal performance. This paper aims to examine permanent magnet motors from a control perspective, highlighting the challenges and opportunities for improving their performance. The additional degree of freedom in VFMs introduces new challenges, requiring modifications and updates to traditional control approaches

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