Why is a brushless DC motor the best choice for aerial work platforms?
Considering the operational characteristics of self-propelled aerial work platforms, the mainstream choice for drive motors in aerial work platforms today is the DC permanent magnet brushless motor. So, what are the advantages of DC permanent magnet brushless motors? Permanent magnet brushless DC motors have emerged and evolved alongside digital control technology, making microcontrollers and DSPs the primary control means for brushless DC motors. Permanent magnet brushless DC motors primarily perform the following control functions.
(1) Commutation control: For systems with position sensors, commutation must be performed regularly based on the position sensor signals to ensure proper switching of phase currents; for systems without position sensors, the commutation points must be calculated based on the induced electromotive force signals to determine which phases should be energized and which should be de-energized.
(2) Speed Control: The speed control principle of
brushless DC motors is the same as that of conventional DC motors. The average voltage of the armature can be controlled via PWM methods to achieve speed regulation. Using single-chip microcontrollers and DSPs with PWM ports enables automatic PWM output, making speed control very straightforward.
(3) Reversal Control: Simply changing the energization sequence of each phase can achieve forward and reverse control of the motor.
During the operation of a permanent magnet brushless DC motor, the windings of each phase conduct alternately in a regular pattern. When a winding is not conducting, the stored energy in the coil generates an induced electromotive force (EMF). The waveform of this induced EMF can be detected at the terminals of the non-conducting winding. By leveraging this characteristic of the induced EMF, the function of a rotor-mounted position sensor can be replaced to obtain commutation information. Consequently, a permanent magnet brushless DC motor with a simpler structure and more reliable performance emerges.
The performance requirements for the drive motor used in self-propelled aerial work platforms specify the selection of a permanent magnet three-phase brushless DC motor as the drive motor.
