Brushless DC Motors constitute a small percentage of the total global production of electric motors. The main workhorse of the electric motors worldwide has been the AC induction motor (3 phase) mainly due to its low manufacturing costs an low maintenance.
The Brushless DC Motors are mainly used in applications where there is no AC power available and where control speed is necessary. Brushless DC Motors are also easier to reverse requiring only change of polarity on the input terminals.
Over the past 2 decades with the advancement and price reduction of the frequency inverters saw the gradual popularity of variable AC drives against the variable DC drives (brushed). The main disadvantage of the brushed DC variable drives is their high maintenance due to the brush wear. Over the last few years with the advancement and price reduction of the rare earth magnets and improvements of the power electronics saw an increase in popularity of the Brushless DC Motors.
The advantages of the Brushed DC Motors over the AC motors are summarized below:

1. higher efficiency
2. lower weight/watt ratio
3. lower volume/watt ratio
4. designed at any speed
5. easier to reverse
6. higher starting torque
7. better speed control (linear characteristics)

The disadvantages of the Brushless DC Motors over the AC motors are:

1. higher maintenance (due to brushes)
2. more expensive

In addition to the above the Brushless DC Motors have the same advantages over AC motors but they also have more advantages over Brushed DC Motors

1. lower maintenance (no brushes)
2. even higher starting torque ( Due to rare earth magnets)
3. even higher efficiency (over 90%) on sub fractional motors
4. even more compact design
5. better heat dissipation
6. lower noise

At “EMP DC MOTOR DYNAMICS” we always strife to achieve the best efficiency for our products by using the best raw material possible. It is well known that by saving energy we assist in more sustainable energy consumption.