Resistance of Earth
Arc Suppression Coil or Petersen Coil
Winding Resistance Test of Shunt Reactor
Measurement of Reactance of a Shunt Reactor
Tests of Shunt ReactorClosely Related Articles
Types of DC Motor Separately Excited Shunt Series Compound DC Motor
Shunt Wound DC Motor | DC Shunt Motor
Series Wound DC Motor or DC Series Motor
Compound Wound DC Motor or DC Compound Motor
Permanent Magnet DC Motor or PMDC Motor | Working Principle Construction
Brushless DC Motors
Electrical Motor | Types Classification and History of Motor
Working of Electric Motor
DC Motor or Direct Current Motor
Speed Regulation of DC Motor
Speed Control of DC Motor
Working or Operating Principle of DC Motor
Torque Equation of DC Motor
Construction of DC Motor | Yoke Poles Armature Field Winding Commutator Brushes of DC Motor
Testing of DC Machine
Swinburne Test of DC Machine
Losses in DC Machine
Ward Leonard Method of Speed Control
Armature Reaction in DC Machine
Commutation in DC Machine or Commutation in DC Generator or Motor
Methods of Improving Commutation
Starting Methods to limit Starting Current and Torque of DC Motor
3 Point Starter | Working Principle and Construction of Three Point Starter
4 Point Starter | Working Principle and Construction of Four Point Starter
Brushless DC Motors
Working Principle of MotorBefore explaining working of brushless DC motor, it is better to understand function of brushed motor. In brushes motors, there are permanent magnets on the outside and a spinning armature which contains electromagnet is inside. These electromagnets create a magnetic field in the armature when power is switched on and help to rotates armature.
The brushes change the polarity of the pole to keep the rotation on of the armature. The basic principles for the brushed DC motor and for brushless DC motor are same i.e., internal shaft position feedback. Brushless DC motor has only two basic parts: rotor and the stator. The rotor is the rotating part and has rotor magnets whereas stator is the stationary part and contains stator windings. In BLDC permanent magnets are attached in the rotor and move the electromagnets to the stator. The high power transistors are used to activate electromagnets for the shaft turns. The controller performs power distribution by using a solid-state circuit.
Types of Brushless DC MotorsBasically, BLDC are of two types, one is outer rotor motor and other is inner rotor motor. The basic difference between the two are only in designing, their working principles are same.
Inner Rotor DesignIn an inner rotor design, the rotor is located in the center of the motor and the stator winding surround the rotor. As rotor is located in the core, rotor magnets does not insulate heat inside and heat get dissipated easily. Due to this reason, inner rotor designed motor produces a large amount of torque and validly used.
Outer Rotor DesignIn outer rotor design, the rotor surrounds the winding which is located in the core of the motor. The magnets in the rotor traps the heat of the motor inside and does not allow to dissipate from the motor. Such type of designed motor operates at lower rated current and has low clogging torque.
Advantages of Brushless DC Motor
- Brushless motors are more efficient as its velocity is determined by the frequency at which current is supplied, not the voltage.
- As brushes are absent, the mechanical energy loss due to friction is less which enhanced efficiency.
- BLDC motor can operate at high-speed under any condition.
- There is no sparking and much less noise during operation.
- More electromagnets could be used on the stator for more precise control.
- BLDC motors accelerate and decelerate easily as they are having low rotor inertia.
- It is high performance motor that provides large torque per cubic inch over a vast sped rang.
- BLDC motors do not have brushes which make it more reliable, high life expectancies, and maintenance free operation.
- There is no ionizing sparks from the commutator, and electromagnetic interference is also get reduced.
- Such motors cooled by conduction and no air flow are required for inside cooling.
Disadvantages of Brushless DC Motors
- BLDC motor cost more than brushless DC motor.
- The limited high power could be supplied to BLDC motor, otherwise too much heat weakens the magnets and insulation of winding may get damaged.
Closely Related Articles Types of DC Motor Separately Excited Shunt Series Compound DC MotorShunt Wound DC Motor | DC Shunt MotorSeries Wound DC Motor or DC Series MotorCompound Wound DC Motor or DC Compound MotorPermanent Magnet DC Motor or PMDC Motor | Working Principle ConstructionMore Related Articles Electrical Motor | Types Classification and History of MotorWorking of Electric MotorDC Motor or Direct Current MotorSpeed Regulation of DC MotorSpeed Control of DC MotorWorking or Operating Principle of DC MotorTorque Equation of DC MotorConstruction of DC Motor | Yoke Poles Armature Field Winding Commutator Brushes of DC MotorTesting of DC MachineSwinburne Test of DC MachineLosses in DC MachineWard Leonard Method of Speed ControlArmature Reaction in DC MachineCommutation in DC Machine or Commutation in DC Generator or MotorMethods of Improving CommutationStarting Methods to limit Starting Current and Torque of DC Motor3 Point Starter | Working Principle and Construction of Three Point Starter4 Point Starter | Working Principle and Construction of Four Point StarterNew Articles System EarthingArc Suppression Coil or Petersen CoilWinding Resistance Test of Shunt ReactorMeasurement of Reactance of a Shunt ReactorTests of Shunt Reactor