A new technique to control brushless motor for blood pump application

Area of Science:

• Biomedical Engineering
• Electrical Engineering
• Control Systems

Background:

• Brushless DC motors (BLDC) are crucial for blood pumps but require shaft position detection.
• Traditional Hall sensors can be unreliable due to signal interference over long distances.
• Sensorless techniques aim to improve reliability and reduce system complexity.

Purpose of the Study:

• To develop and evaluate a sensorless detection technique for BLDC motor drivers.
• To eliminate the need for Hall sensors in BLDC motor applications.
• To assess the viability of a back-electromotive force (BEMF)-based method for blood pump drivers.

Main Methods:

• Simulated BLDC motor operation using PSpice.
• Designed and constructed a BEMF detector circuit.
• Compared BEMF signals with Hall sensor signals in a controlled setup.

Main Results:

• The sensorless BEMF detection signals closely matched Hall sensor signals.
• Effective performance was observed at motor speeds exceeding 2500 rpm.
• The technique demonstrated potential for reliable operation in BLDC drivers.

Conclusions:

• The BEMF-based sensorless technique is a viable alternative to Hall sensors for BLDC drivers.
• This method is recommended for rotary blood pumps as a primary or redundant system.
• Sensorless operation enhances system robustness by mitigating interference issues.