Low-Speed Permanent Magnet Synchronous Motor Rotor Position Estimation Using Structural Vibration Modal Phase Carrier

Area of Science:

• Electrical Engineering
• Mechanical Engineering
• Vibration Analysis

Background:

• Traditional sensorless control methods struggle with low-speed accuracy due to diminished back-electromotive force (back-EMF) and high noise.
• Existing electrical signal-based methods face inherent limitations in low-speed operational regimes.

Purpose of the Study:

• To propose and validate a rotor position estimation method utilizing structural vibration characteristics for enhanced low-speed sensorless control.
• To establish the physical basis for employing vibration phase as a reliable carrier of rotor spatial information.

Main Methods:

• Analysis of the coupling mechanism between air-gap electromagnetic force density and stator structural vibration modes.
• Development of a workflow for signal acquisition, modal selection, and phase calculation.
• Integration of the vibration-based method into a sensorless control system for simulation and validation.

Main Results:

• The proposed method demonstrates stable rotor position estimation even under significant noise interference.
• Simulation results show superior performance and reduced estimation error compared to conventional back-EMF-based methods in the low-speed region.
• The effectiveness and robustness of the vibration-based approach at low speeds are validated.

Conclusions:

• Structural vibration characteristics offer a viable alternative for rotor position estimation in sensorless control systems.
• Utilizing non-electrical structural information provides a complementary channel to overcome the limitations of electrical-signal-based methods at low speeds.
• This research presents a promising new direction for improving the accuracy and reliability of low-speed motor control.