BLDC MACHINE

Below are the comparison between high torque density of single stator with high torque density double stator 

 

For district comparative evaluations, the motor constant square density G is used to quantify the level of performance.  The motor constant square density has considered the torque, power and volume of a particular motor which is good for comparison purposes.

 

  The motor constant square density can be expressed as,       

 

       

 

                                                                           [Nm²A²/W/m³]        

 

                                                                            

 

                                                                           [Nm/A/W^(1/2)]                

 

                                                                               

 

                                                                           [Nm/A]                    

 

 

where K_m is the motor constant in [Nm/A/W^(1/2)], V is the volume of the overall motor [m³], K_T is the torque constant in [Nm/A], W is the input power of coil in [W], T_f is the fundamental torque in [Nm] and I is the maximum  input current in [A].

 

For some researcher, another established comparison is torque density which only considered torque and volume only. Torque density can be defined as below.

 

 

                                                                                         

                                                                            [Nm/A/ m³]