Motorcycle Starter Motor Electronic Commutation
Motorcycle Starter Motor Electronic commutation
Brushless DC editing
Brushless DC motor is the use of semiconductor switching devices to achieve electronic commutation, that is, with electronic switching devices instead of the traditional contact commutator and brush. It has the advantages of high reliability, no change in sparks and low mechanical noise. It is widely used in high-grade recording blocks, video recorders, electronic equipment and automatic office equipment.
Brushless DC motor consists of permanent magnet rotor, multi-pole winding stator, position sensor and other components. The position sensor converts the current of the stator winding in a certain order according to the change of the position of the rotor (that is, the position of the rotor pole relative to the stator winding is detected and the position sensing signal is generated at the determined position and processed by the signal conversion circuit To control the power switch circuit, according to a certain logical relationship between the winding current switching). The operating voltage of the stator winding is provided by the electronic switch circuit controlled by the position sensor output.
Position sensors are magnetic, photoelectric and electromagnetic three types. A brushless DC motor using a magnetic sensor is mounted on a stator assembly, such as a Hall element, a magnetically susceptible diode, a magneto-sensitive transistor, a magnetoresistive resistor, or an application specific integrated circuit, To detect the permanent magnet, the rotor rotation when the magnetic field changes.
A brushless DC motor using a photoelectric position sensor is provided with a photoelectric sensor at a certain position on the stator assembly. The rotor is provided with a light shielding plate, and the light source is a light emitting diode or a small light bulb. Rotor rotation, due to the role of the shading plate, the photosensitive element on the stator will be a certain frequency intermittent pulse signal.
The brushless DC motor with electromagnetic position sensor is equipped with electromagnetic sensor components (such as coupling transformer, proximity switch, LC resonant circuit, etc.) on the stator assembly. When the position of the permanent magnet rotor changes, the electromagnetic effect will make the electromagnetic sensor Generates a high frequency modulated signal whose amplitude varies with the rotor position.
DC motor with a fast response, a large starting torque,
From the zero speed to the rated speed with the rated torque can provide the performance, but the advantages of DC motor is also its shortcomings, because the DC motor to produce a constant load rated torque performance, the armature magnetic field and the rotor magnetic field to be constant To maintain 90 °, which will rely on carbon brush and commutator. Carbon brushes and commutators produce sparks when the motor rotates, and the toner is limited in addition to damage to the components. AC motor without carbon brush and commutator, maintenance-free, strong, wide application, but the characteristics of the DC motor to achieve the equivalent of the performance of complex control technology to be used to achieve. Now the rapid development of semiconductor power components to switch the frequency to speed up a lot, to enhance the performance of the drive motor. Microprocessor speed is faster and faster, can be achieved AC motor control placed in a rotating two-axis orthogonal coordinate system, the appropriate control of AC motor in the two-axis current component, to achieve similar DC motor control and DC motor equivalent performance.