Disadvantages of BLDC Motor [2022]

The disadvantages of BLDC motor might appear to be quite a surprising topic of discussion, as modern industrialization is based almost entirely on the Brushless DC Motors. As we have entered the age of absolute precision, the BLDC is an efficient choice. This motor choice allows modern machinery to stay lightweight, reliable, cost-competitive, and compact. But what is a Brushless DC motor, and why is it called so? Let’s learn a bit more before we indulge in its advantages and disadvantages.

DISADVANTAGES OF BLDC MOTOR

This is also known as the Electronically commuted Motor (ECM or EC motor) or Synchronous, and it uses the Direct Current or the DC electric supply to function. These do not feature the customary Brushes where the Controller is responsible for providing the current in ‘Pulse’ to the motor windings. This is also responsible for controlling the speed and torque of the Synchronous Motor.

What Makes the BLDC Motors So Special?

As mentioned earlier, the BLDC motors have taken over our industrious needs by storm. These have found widespread application in most electronics and electrically powered devices. It is essentially because of the high torque over the vast speed range. The construction of the BLDC motor comprises of permanent motor that rotates about a fixed armature. To understand precisely, it is safe to declare that the BLDC motors contain two basic parts: The Rotor and the Stator. As the name suggests, the Rotor is the part that rotates and comprises rotor magnets, and the stator is the stationary part and comprises Stator Windings.
The BDLC motor working comprises permanent magnets attached to the Rotor and constructed to move the electromagnets to the stator. High-power transistors power the electromagnets. Another part known as the Controller is responsible for the power distribution with the help of the Solid state circuit.

The BLDC Motor Types

Before we get into discussing the BLDC motor disadvantages, let us take a look at the BLDC motor types:

Inner Rotor Design

This BLDC motor design comprises the Rotor located in the middle of the motor with the Stator windings surrounding the Rotor. With the Rotor located at the core, there are no chances of heat being insulated within, as it dissipates smoothly. Large torque can be easily created in the Inner Rotor Design; hence, this finds wide application.

Outer Rotor Design

In this design type, the stator windings Are surrounded by the Rotor. The magnets trap the heat produced by the Rotor motor; hence, the heat is not dissipated from the motor. The Outer Rotor Design utilizes a lower rated current and generates low cogging torque.

The Disadvantages of BLDC Motor

The BLDC motors are more expensive as compared to the Brushed DC Motors.

  • It has to be ensured to maintain the Power supply in a BLDC motor as too much heat can weaken the magnets, also damaging the windings in the process.
  • When operated at a lower speed range, with the Brushless DC motors, low-frequency vibrations occur at low-speed rotation.
  • The operation and construction of Brushless Motors are not simple, as it involves electromagnets and various electronic controls.

The Advantages of BLDC Motor

The BLDC motors are high in efficiency. This is because there is no excitation loss compared to AC motors. Also, there is no brush friction loss or no sparks either.

  • These are resistant to vibrations and low noise.
  • The BLDC ensures the long life of the device or the appliance and smooth operation.
  • With the absence of Carbon Brushes, one does not have to worry about replacement and maintenance costs.
  • This motor type also comprises a low load current requirement; hence, it can easily operate at a low or even no load.
  • There is an elimination of ionizing spark from the commutator.
  • Have a longer lifespan in comparison.
  • Can also deliver silent operation.

BLDC Ceiling Fan Disadvantages

As mentioned previously, the challenges of BLDC fans are similar to that of the BLDC motors:

  • These are more expensive compared to the Brushed Ceiling fans. This is because the BLDC fans comprise an electronic controller, which is much pricier than the regular fans’ low-cost mechanical commutation arrangement.
  • It has been observed that the BLDC fans suffer from low-speed vibrations, giving rise to the resonance phenomenon. Nevertheless, this can be reduced when the fan’s speed increases.

  • It is quite a challenge to install the BLDC fans, and this is because it also involves a Controller, which makes it tough for a regular technician to do the job. On the other hand, regular fans have a rather straightforward wiring process that makes them easy to install.

Disadvantages of BLDC Motor: The Conclusion

So, here you have all the BLDC motor fan disadvantages, facts, and the same features. While it might be an expensive choice, it is quite popular due to its durability and longevity.