Advanced Control Strategies for Magnet-Free Synchronous Motors

Dear Colleagues,

Synchronous motors play a crucial role in various applications, including constant and variable speed drives. Notably, they find extensive use in electric and hybrid electric vehicles.

Synchronous motors include not only permanent magnet (PM) SMs that can be either interior or surface-mounted, but there are other magnet-free candidates such as wound-rotor SMs, synchronous reluctance, and doubly salient synchronous reluctance motors (which are essentially switched reluctance motors supplied by sinusoidal currents and a voltage source inverter).

Due to the existence of a rare-earth material in PMSMs, researchers have turned their attention to other magnet-free options due to environmental concerns and supply limitations. However, the performance of these alternatives still lags behind that of PMSMs.

Unlike PMSMs, where both permanent magnet torque and reluctance torque contribute to overall torque production, magnet-free SMs rely solely on reluctance torque. This results in lower torque and power density, higher torque ripples, and possible higher radial forces. Additionally, the absence of the magnet which is an excitation or reactive power source in PMSMs results in a lower power factor in magnet-free motors.

We are pleased to invite you to submit state-of-the-art manuscripts to this Special Issue aimed at narrowing the performance gap between magnet-based and magnet-free SMs. Topics of interest include (but are not limited to) the following:

• Parameter estimations and observers applied to SMs.
• Control strategies that aim to improve efficiency, torque ripple and radial forces reduction, extended speed operation, and power factor improvement.
• Machine learning used in SM control applications.
• Modelling techniques of radial and tangential forces.
• Fault-tolerant control strategies for SMs.

We can advance the field together!

Dr. Peter Azer
Dr. Ahmed Abdelrahman
Guest Editors

Manuscript Submission Information

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• synchronous motors
• motor control
• power electronics
• electric machines