The difference between brushless motor and servo motor used in turnstile gate
The difference between brushless motor and servo motor used in turnstile gate
The difference between a servo motor and a brushless motor is whether they are equipped with commonly used brush-commutators. The commutation of the servo DC motor has always been achieved by the graphite brushes contacting the ring commutator mounted on the rotor.
The brushless motor feeds the rotor position back to the control circuit through the Hall sensor, so that it can know the exact time of the motor phase commutation.
Most brushless motor manufacturers produce motors with three Hall-effect positioning sensors. Since brushless motors do not have brushes, there are no related interfaces, so they are cleaner and less noisy. In fact, they require no maintenance and have a longer life. In the case of brushless DC motors, the rotor poles usually use tile-shaped magnetic steel. After the magnetic circuit design, the air gap magnetic density of the trapezoidal wave can be obtained. The stator windings mostly use concentrated full-length windings, so the induced back EMF is also trapezoidal.
The control of the brushless DC motor requires position information feedback. It must have a position sensor or use a position sensorless estimation technology to form an automatic control speed control system. During the control, the current of each phase is also controlled as square wave as possible, and the output voltage of the inverter can be controlled according to the PWM method of the brushed DC motor. In essence, the brushless DC motor is also a permanent magnet synchronous motor, and the speed regulation actually belongs to the category of variable voltage and variable frequency speed regulation.
Generally speaking, the AC permanent magnet synchronous servo motor has a stator three-phase distributed winding and a permanent magnet rotor. On the magnetic circuit structure and winding distribution, the induced electromotive force waveform is ensured to be sinusoidal, and the applied stator voltage and current should also be sinusoidal. Transformer inverter is provided. Permanent magnet synchronous motor control systems often use self-control, but also need position feedback information. Vector control (field-oriented control) or advanced torque control can be used.
Liǎng zhě qūbié kěyǐ rènwéi shì fāng bō hé zhèngxián bō kòngzhì dǎozhì de shèjì lǐniàn bùtóng. Zuìhòu míngquè yīgè gàiniàn, wú shuā zhíliú diànjī de suǒwèi “zhíliú biànpín” shízhì shàng shì tōngguò nì biàn qì jìnxíng de jiāoliú biànpín, cóng diànjī lǐlùn shàng jiǎng, wú shuā zhíliú diànjī yú jiāoliú yǒng cí tóngbù sìfú diànjī xiāngsì, yīnggāi guī lèi wèi jiāoliú yǒng cí tóngbù sìfú diànjī; dàn xíguàn shàng bèi guī lèi wèi zhíliú diànjī, yīnwèi cóng qí kòngzhì hé qūdòng diànyuán yǐjí kòngzhì duìxiàng de jiǎodù kàn, chēng zhī wèi “wú shuā zhíliú diànjī” yě suànshì héshì de.展开165/5000The difference between the two can be considered as the design concept caused by the square wave and sine wave control. Finally, a concept is clarified. The so-called "DC frequency conversion" of the brushless DC motor is essentially AC frequency conversion through the inverter. In theory, the brushless DC motor is similar to the AC permanent magnet synchronous servo motor and should be classified as AC permanent magnet synchronous servo motor; but it is traditionally classified as a DC motor, because from the perspective of its control and driving power supply and control object, it is also appropriate to call it "brushless DC motor"
