BLPM motors and ECU
MAHLE brushless permanent magnet motors with ferrite or rare earth magnets on the rotor combine high performance and reliability with a simple design, resulting in optimal price-performance ratios. The multipole motors offer high efficiency (> 90%) over a wide speed range and high torque at low speeds. Using a special motor design, the cogging torque level is extremely low. The motor has no commutator and brushes, nor slots and windings on the rotor. This ensures very low acoustic noise and torque ripple. This type of motor is powered and controlled by separate or built-in BLPM ECUs, whose basic function is to provide the electronic commutation to stator phases based on the rotor position (detected by an integrated absolute encoder).
Communication from/to external electronic devices is done by using analog signals, digital I/O, PWM signals, or CANOpen communication. Integrating the ECU in the motor housing creates a single, compact drive unit. Typical applications for such motor versions are steering applications and small traction motor drives. BLPM drive systems are available in both low- (12–80V) and high-voltage ranges (200–450V). Most comply with the automotive industry ECE R10-5 standards for EMC emissions and immunity.