Synchronous Sampling-Based Direct Current Estimation Method for Self-Sensing Active Magnetic Bearings.

Area of Science:

• Engineering
• Control Systems
• Mechatronics

Background:

• Active magnetic bearings (AMBs) often use pulse-width modulation, leading to sensing accuracy and stability issues.
• Existing methods struggle with phase shift and dynamic performance, particularly at high rotor velocities.

Purpose of the Study:

• To propose a novel synchronous sampling-based direct current estimation (SS-DCE) method for improved sensing in AMBs.
• To enhance rotor position detection accuracy and stability, especially under dynamic conditions.

Main Methods:

• Developed a mathematical model coupling rotor displacement with voltage/current, considering reluctance evolution.
• Established a direct current estimation (DCE) for rotor position using estimated inductance during charging/discharging phases.
• Implemented SS-DCE to minimize phase shift and enable precise position detection at high velocities.

Main Results:

• The SS-DCE method significantly improved sensing accuracy and stability compared to existing techniques.
• Achieved a linearity improvement for the SS-DCE method, controlled below 4%.
• Demonstrated excellent dynamic accuracy with a phase margin of 158° at 19.26 Hz and peak sensitivity of 10.7 dB.

Conclusions:

• The proposed SS-DCE method effectively addresses sensing accuracy and stability problems in AMBs.
• SS-DCE offers superior dynamic performance and precise rotor position detection for high-speed applications.
• This method provides a robust and accurate solution for active magnetic bearing control systems.