BLDC motors or brushless DC motors are also known as electronically commutated motors or ECMs. They are a type of synchronous motor, i.e., an electric motor which have speed proportional to the current frequency applied. They are powered by the DC electric supply which produces an AC power supply responsible for driving each phase of the motor. The controller is used to provide pulses of current supply to the DC motor windings. These windings, in turn, control the speed and torque of the motor. The motor structure of the brushless DC motor usually consist of a permanent magnet synchronous motor but can also be a switched to reluctance or induction variant.
Brushed DC motors have been present for a long time roughly since mid 19th century, but the technological advancements have resulted in the invention of more convenient and efficient motors in the form of brushless DC motors. A brushed DC though heavily relied upon had many limitations in the form of low efficiency, more power consumption and vulnerability to wear and tear. Brushless DC motors dealt with all these restrictions of the Brushed DC motors but at the cost of comparatively more complex and expensive control mechanisms.
Brushless DC motors carry several advantages over the brushes motors which include high torque to weight ratio, increased efficiency in terms of more torque per watt and more reliability. It also has a prolonged lifetime as compared to the brushed ones, reduced level of noise and significant reduction in the electromagnetic interference in its applications due to absence of ionizing spikes from the brushes . Windings are absent from the rotors of this variation of a motor and hence are not affected by the centrifugal forces. Additionally, the housings are used to support the windings and hence does not require airflow inside the motor system and can be cooled by conduction method. With the absence of airflow, the interiors of the motor are protected from the dirt, grease, oil or any other matter which might disrupt its functioning or cause premature wear and tear. The Brushless motor computation is usually implemented in software which allows it to possess greater flexibility and capability. The computation can also be customized to specific motors used for different applications and hence increases its efficiency and usability. They are also more suitable for applications in hazardous environments since they are in a sealed enclosure. They are also considered virtually maintenance free.
Having greater efficiency and longer lifespan the Brushless DC motors have found its applications in various fields like consumer electronics, transportations, medical, heating and ventilation applications, industrial and model engineering.
The BLDC fans are increasingly being manufactured and used as compared to its brushed motor fan counterpart as it achieves the same results as the latter while requiring lesser electric supply. The conventional fans which employed brushed DC motors typically consume 70-80 Watts of the electric power supply providing air delivery ranging between 230 to 250 m3/min. While the BLDC fans require only 45-50 Watts of power supply and it delivers about 210 to 225 m3/min of air.
BLDC motor fans have recently been launched in the market in about a span of 5-6 years, but there are various brands in the market which manufacture fans based on the Brushless DC motors. The premier manufacturing companies being Atomberg, Orient Electric, SuperFan, Luxaire, and Orbit Greens.
These fans come in similar sleek and trendy designs and though they cost a bit higher than the conventional fans with brushed DC motors since BLDC fans are more efficient and reliant and consume less energy it has reduced the impact on the consumer’s’ pocket and hence is receiving a favorable response from them.