Welcome to electrical and electronics engineering Q&A site...

Welcome to electrical and electronics engineering discussion website, Please login or register to continue.

Join our WhatsApp group

Subscribe To Our YouTube Channel

13 views
by
With the help of necessary sketch, explain in brief the working of brushless DC motor. 

Amazon Shopping

Please log in or register to answer this question.

1 Answer

0 votes
by

Constructional Diagram of Brushless DC Motor:

image

Working of brushless DC motor: The brushless DC motor is the combination of a permanent excited synchronous motor and a frequency inverter. The inverter has to replace the commutator of a conventional DC motor. Fig. 2 and Fig. 3 show how a brushless DC motor can be derived from a mechanically commutated DC motor with three armature slots. Its armature winding corresponds to a three phase winding in delta connection. The commutator acts like a three phase frequency converter. Stator (excitation) and rotor (armature) change places. The construction of brushless DC motor is similar to that of permanent magnet synchronous motor. The commutation of a brushless DC motor depends on the position of the rotor. The angle between the magneto-motive forces of stator and rotor is fixed to 900 (el.), so the motor produces maximum torque and needs low reactive current - it might be useful to advance commutation by few degrees to compensate the effects of the stray inductance and minimize reactive current. Speed can only be controlled by the the motor voltage. The motor behaves like a DC motor. Unlike the synchronous motor there are no problems with instability at any speed. Because of the PWM frequency inverter, variation of the motor voltage can be achieved easily by changing the duty cycle of the pulse width modulation. Suitable PWM techniques allow regenerative breaking, which increases dynamic and efficiency of the drive. 

Amazon Shopping

Welcome to Q&A site for electrical and electronics engineering discussion for diploma, B.E./B.Tech, M.E./M.Tech, & PhD study.
If you have a new question please ask in English.
If you want to help this community answer these questions.

Categories

Most popular tags

power motor dc circuit transformer voltage current used system phase factor resistance load synchronous energy ac induction generator electric series frequency capacitor use speed between meter electrical line type mosfet control transmission difference magnetic plant high single instrument bjt source advantages function diode machine unit winding torque amplifier define supply thyristor motors arduino field shunt maximum relay armature problem electricity time parallel on transformers types coil diagram state flow value material three starting and direction theorem method emf operating digital microprocessor test instruments efficiency ratio loss measure operation connected low applications wave effect single-phase working losses different network wattmeter temperature measuring constant signal controlled breaker device full compare drive wire resistivity logic materials machines inductance switch flux disadvantages converter transistor gain protection scr angle force core measurement number free principle rc generators law negative bridge friction open pole conductor conservation steam iron loop resistors hysteresis short computer using lines secondary station battery rectifier inverter linear relays nuclear regulation circuits design analog work rotor electronics gate forces diesel damping rlc connection factors capacitors minimum insulation basic moving running reactance systems air fault range direct main stability quality starter igbt eddy ideal ammeter rl 3-phase plants arc induced thermal error fuzzy biasing dielectric pressure balanced superposition errors rotation characteristics feedback measured electronic start alternator off back curve over solar three-phase tariff locomotive peak bias zener capacitance commutator surge rating universal potentiometer permanent mechanical copper self transducer capacity electrons memory adc excitation inductive transfer explain fuse pure harmonics application internal pmmc average reaction welding resonance traction breakers designed electromagnetic si generation brushes density switching shaded rate impedance distribution methods star oscillator reluctance semiconductor inductor simplification algebra 8085 boolean weston dynamometer insulating strength installation permeability definition fuel heating earth units neutral rms rated engineering conductors coefficient controller usually reverse excited analysis change body components
...