Full-speed domain position sensorless control strategy for PMSM based on improved super-twisting sliding-mode...

Area of Science:

• Electrical Engineering
• Control Systems
• Robotics

Background:

• Sensorless control of permanent magnet synchronous motors (PMSMs) faces challenges in achieving smooth speed transitions, particularly from low to medium-high speed ranges.
• Existing methods often struggle with stability and accuracy during these critical transitional phases.
• Accurate rotor position and speed estimation are crucial for effective PMSM control.

Purpose of the Study:

• To develop a full-speed range control algorithm for PMSMs that overcomes limitations in smooth speed transitions.
• To enhance the robustness and accuracy of sensorless control algorithms in dynamic operating conditions.
• To improve the overall performance and stability of PMSMs during speed changes.

Main Methods:

• A novel algorithm fusing pulsating high-frequency injection (HFI) with square waves for low-speed operation.
• Implementation of an improved super-twisting sliding-mode observer (STSMO) with a variable gain (VGLSTSMO) for medium-high speeds.
• Integration of an adaptive back electromotive force (back-EMF) model and a Sine-weighted switching function for seamless transitions.

Main Results:

• The proposed method achieves smooth and stable operation across the entire speed range of PMSMs.
• Rotor position estimation errors were reduced to approximately 0.2 radians using the improved STSMO.
• The Sine-weighted switching function effectively facilitated smooth transitions between low and medium-high speed domains.

Conclusions:

• The fused HFI and improved STSMO algorithm provides a robust solution for sensorless PMSM control.
• The developed method significantly enhances performance during speed transitions, addressing a key challenge in the field.
• This approach offers a promising direction for achieving high-performance, full-speed range operation of PMSMs without mechanical sensors.