Latest from Automotive

ID 312689142 © Chechotkin | Dreamstime.com
LiDAR in autonomous driving
ID 39977536 © Pino Carboni | Dreamstime.com
Transformers on a PCB
ID 326211957 © Kwangmoo | Dreamstime.com
Security IP CCTV camera using solar energy
ID 319909889 © Media Whalestock | Dreamstime.com
Needles on automatic test equipment
325988743 © aleksei todosko | Dreamstime.com
id_325988743__aleksei_todosko__dreamstime
Dreamstime_kpixmining_229797125
dreamstime_kpixmining_229797125
Www Electronicdesign Com Sites Electronicdesign com Files Ti Bld Ccontrol Fig1

Sine of the Times for BLDC Motors (.PDF Download)

Feb. 12, 2018
Sine of the Times for BLDC Motors (.PDF Download)

With its ever-increasing electronic content, the modern automobile places a premium on energy-efficient design. That’s doubly true for hybrid-electric and full-electric vehicles (HEVs and EVs), in which the battery is the main or only source of power.

1. Should have used sinusoidal control: Torque ripple in his helmet motor confounds Darth Vader (Source: Sky.com)

The search for longer battery life has led to the increasing adoption of brushless dc (BLDC) motors over brushed designs. In traditional automobiles with internal combustion engines, BLDCs power accessories such as electric mirrors, fans for ventilation and cooling, and seat motors; in HEVs and EVs, applications expand to include former mechanical and hydraulic functions such as traction motors, generators, AC compressors, water pumps, and power-steering actuators. And let’s not forget two-wheel automotive applications: BLDCs are also making their way into motorcycle and scooter fuel-pump controls.

BLDCs have higher efficiency, higher torque-to-weight ratio, lower maintenance, higher reliability, and lower noise than their brushed motor counterparts. The downside is that they require considerably more electronic circuitry to operate.

A brushed dc motor has a wound armature (rotor) placed between the poles of a magnet

(stator), and uses the brushes to mechanically switch current to the armature and cause it to rotate—a  process known as commutation. In contrast, a BLDC has a wound stator with multiple windings that surrounds a permanent-magnet rotor assembly. A controller provides electronic commutation by monitoring the rotor position and supplying power to the stator windings in the correct sequence to start and maintain rotor motion.

Comments

To join the conversation, and become an exclusive member of Electronic Design, create an account today!