The BLDC and PMSM motors can be the same or different depending on the researchers' views. Basically they are synchronous motors with permanent magnets attached on their rotors.

Some researchers define a BLDC motor is a PMSM with trapezoidal BEMF, while a BLAC is a pmsm with sinusoidal BEMF.

The drive techniques for BLDCMs and sinusoidal PMSMS are quite different, as I said, depending on BEMF shape, but drive techniques for BLDCMs (typically 2-phase excitation) can be applied to PMSMS, and vice versa.

Hope my answer helps.

Thank you

what about the nature of stator fed ( supply )?, and all their results quantity (induced and ....)?

Regards

The BLDC and PMSM motors can be the same or different depending on the researchers' views. Basically they are synchronous motors with permanent magnets attached on their rotors.

Some researchers define a BLDC motor is a PMSM with trapezoidal BEMF, while a BLAC is a pmsm with sinusoidal BEMF.

The drive techniques for BLDCMs and sinusoidal PMSMS are quite different, as I said, depending on BEMF shape, but drive techniques for BLDCMs (typically 2-phase excitation) can be applied to PMSMS, and vice versa.

Hope my answer helps.

In BLDC machine, the stator winding is concentrated. Hence the stator waveform will be trapezoidal. Whereas in PMSM the stator winding is distributed winding. Hence the stator waveform is sinusoidal. As far as rotor is concern both are permanent magnet.

With thanks and Regards

Rajin M. Linus

pmsm motor have sinusoidally distributed stator windings, whereas a bldc motor have salient type field coils

In these only difference is of current applied on stator

hi dear friends.

BLDC is one of tyoe of DC motors.this motors are not Brush and commutator.BLDC motor is a permanent magent DC motor.in this motor,brushs and commutator are removed and uses a inverter for speed and tuequ control.in this motor uses 3 hall sensor for traching of rotor.roto in this motor made of from permanent magent.approximatly, this motor is one of the types from PMSM with hall sensorsµc ontroller.

BLDC motor is similar to a DC motor in performance but without brushes. It is a new kind of Motor which quickly maturated with the development of the power electronics and high flux density permanent magnetic materials. Recent research [1] has indicated that the permanent magnet motor drives, which include the permanent magnet synchronous motor (PMSM) and the brushless dc motor (BLDCM) could become serious competitors to the induction motor for servo applications. Many papers and journals have been published on BLDC motors regarding the operation, speed control methods and so on.

The Brushless DC (BLDC) motor is the ideal choice for applications that require high reliability, high efficiency, and high power-to-volume ratio. Generally speaking, a BLDC motor is considered to be a high performance motor that is capable of providing large amounts of torque over a vast speed range. BLDC motors are a derivative of the most commonly used DC motor, the brushed DC motor, and they share the same torque and speed performance curve characteristics. The major difference between the two is the use of brushes. BLDC motors do not have brushes (hence the name "brushless DC") and must be electronically commutated.

Commutation is the act of changing the motor phase currents at the appropriate times to produce rotational torque. In a brush DC motor, the motor assembly contains a physical commutator which is moved by means of actual brushes in order to move the rotor. With a BLDC motor, electrical current powers a permanent magnet that causes the motor to move, so no physical commutator is necessary.

A BLDC motor is highly reliable since it does not have any brushes to wear out and replace. When operated in rated conditions, the life expectancy is over 10,000 hours. For long term applications, this can be a tremendous benefit. Whenever a motor breaks down or needs to be replaced, your project, or part of it, must be shut down. This costs you time and money, perhaps a great deal depending on how long it takes to replace the worn part or parts and get the application started again. Although a BLDC motor may cost more than a brushless motor, it will often more than pay for itself in the amount of work time saved.

I will refer you to the paper:

Pragasen Pillay and Ramu Krishnan, "Application Characteristics of Permanent Magnet Synchronous and Brushless dc Motors for Servo Drives", IEEE Trans. on Industry Apps, Vol. 27, No. 5, 1991

It contains detailed description of the key differences between BLDC and PMSM.

Both of them is a synchronous motor 

The main difference is winding and supply 

                    for PMSM  sinusoidal winding and sinusoidal supply 

                    for BLDC trapezoidal winding and trapezoidal supply 

These are types of SM.

BLDC-

      Trapezoidal back emf

      Square wave current

      Concentrating winding

PMSM-

      Sinusoidal back emf

      Sinusoidal current

      Distributed winding

But elctrical mashine with sinusoidal back EMF anyway can be controlled similar as BLDC..

Dear all,

Would it be possible to control a PMSM motor with a BLDC drive?

Thanks in advanced for your answers

In BLDC you have DC which means Direct Current, these motors have a permanent magnets but they have a trapezoidal Bemf, this imply that we must generate a trapezoidal phase voltages => current shape will be continuous by parts in time. In the other side, PMSM have also permanent magnets but they have a sinusoidal Bemf, this imply to generate a sinuoidal voltage shapes or other equivalent shapes (SVM, flat-bottom, ...) and this lead to a sinusoidal current wich will be synchronised to motor Bemf in order to maximize efficiency.

In my perspective BLDC motor has pro's- less switching loss, control algorithm relatively simple & con's-high core loss due to harmonic content compared to its counterpart PMSM (vice versa for it is true)

i think that the control phase is more easy for the BLDC than in a PMSM.