I understand it, "Permanent Magnet Brushless Motor" should be said that the difference between BLDC and PMSM really hard to say, sometimes depending on the application. Tradition says that they have different counter electromotive force, BLDC close to a square wave, PMSM close to a sine wave. BLDC control is generally used 6 meter square wave drive, control and square wave inverted phase on time, PMSM use FOC. Performance for large output power density point BLDC because BLDC torque full use of harmonics, harmonics and therefore a serious point of BLDC.