Brushless permanent magnet motors (BLDCMs) and self-controlled permanent magnet synchronous motors (PMSMs) are essentially identical in structure in terms of the motor body itself: the three-phase armature windings are located on the stator, and the permanent magnet poles are located on the rotor. However, their operating principles and control modes differ. Today, Ms. Can will summarize and share the differences between the two in terms of magnetic field and applications.
BLDCM is the abbreviation for Brushless Direct Current Motor ; PMSM stands for Permanent Magnet Synchronous Motor. The difference lies in their magnetic fields.
Under normal circumstances, if the three-phase armature windings of the motor are connected to a unipolar non-bridge electronic commutation (phase) circuit or a 120° conduction type half-bridge inverter circuit; the driving voltage is a DC rectangular wave voltage, and it is desirable that the rotor permanent magnet poles can generate a magnetic field close to a rectangular wave or trapezoidal wave in the working air gap, thereby inducing a back electromotive force close to a rectangular wave or trapezoidal wave in the armature windings; when the motor is running, the three-phase armature windings are usually conducted one phase at a time or two phases at a time, generating a "jumping" rotating magnetic field in the working air gap, we call such a permanent magnet motor a brushless DC permanent magnet motor, or simply a brushless DC motor (BLDCM).
Under normal circumstances, if the three-phase armature windings of the motor are connected to a 180° conducting half-bridge inverter circuit; the driving voltage is a pulse voltage modulated by a sinusoidal pulse width, or a pulse voltage modulated by a space vector pulse width, it is desirable that the rotor permanent magnet poles can generate a magnetic field with a near-sinusoidal waveform in the working air gap, thereby inducing a back electromotive force with a near-sinusoidal waveform in the armature windings; when the motor is running, the three-phase armature windings are simultaneously connected, generating a "continuous" circular rotating magnetic field in the working air gap. We call such a permanent magnet motor a self-controlled permanent magnet synchronous motor (PMSM).
Motor characteristics and applications
Brushless DC hydromagnetic motors (BLDCMs) and self-controlled permanent magnet synchronous motors (PMSMs), besides both having linear mechanical characteristics, also have different features and different application areas.
● Features and Applications of Brushless DC Permanent Magnet Motors (BLDCM)
1) The armature winding is not fully utilized;
2) It is desirable that the rotor permanent magnet poles can generate a magnetic field close to a rectangular or trapezoidal wave within the working air gap:
3) Hall effect sensors are typically used as rotor position sensors for electric motors;
4) The control circuit is relatively simple;
5) The torque pulsation is relatively large;
6) The control precision is relatively low;
7) The price is relatively cheap.
Brushless DC permanent magnet motors (BLDCMs) are suitable for single-speed and stable-speed operation applications with power ratings below 300W, such as computer floppy disk drives (FDDs), hard disk drives (HDDs), spindle drives for audio-visual equipment, laser printers, electric bicycles, automotive motors, forklifts, lifting mechanisms, electric sewing machines, fans, pumps, etc.
●Characteristics and application areas of self-controlled permanent magnet synchronous motors (PMSM)
1) Make good use of the armature winding;
2) It is desirable that the rotor permanent magnet poles can generate a near-sinusoidal magnetic field within the working air gap;
3) Non-contact rotary transformers are typically used as rotor position sensors for electric motors;
4) The control circuit is relatively complex;
5) Small torque pulsation;
6) High control precision and good dynamic performance;
7) The price is relatively high.
Self-controlled permanent magnet synchronous motors (PMSMs) are suitable for precision servo control systems with power ratings of 500W and above, such as CNC machine tools, textile machinery, papermaking machinery, precision positioning systems, and robots.
Disclaimer: This article is a reprint. If it involves copyright issues, please contact us promptly for deletion (QQ: 2737591964 ) . We apologize for any inconvenience.
