Design of optimal digital controller for stable super-high-speed permanent-magnet synchronous motor

A new collaborative design scheme of a super-high-speed permanent-magnet synchronous motor (PMSM) and its digital controller is presented, which provides a low-cost but highly efficient motor system with guaranteed stability and performance. Since the systematic design of the PMSM can ensure its stability over the full operating speed range, a simple and reliable open-loop controller can be designed for the super-high-speed motor. With stability assurance, an optimal digital control is also designed in order to enhance the efficiency and performance of the PMSM. The unique feature in the proposed optimal V/f control is its design consideration to the stator resistor, which is generally neglected in most V/f controls but cannot be neglected in the super-high-speed motor owing to the extra small-size requirement. The simulation and stability analysis for various design options are provided. Finally, simulation and experimental results validate the design technique and its effectiveness.