Vidin'ny motera 5 hp 2 any India
Classification: the rotor is excited by direct current. Its rotor is made of pole display type. The magnetic field coils installed on the magnetic pole iron core are connected in series with alternating opposite polarity, and two leads are connected to the two slip rings installed on the shaft. The field coil is excited by a small DC generator or battery. In most synchronous motors, the DC generator is installed on the motor shaft to supply the excitation current of the rotor pole coil.
Since the synchronous motor can not start automatically, the rotor is also equipped with a squirrel cage winding for motor starting. The squirrel cage winding is placed around the rotor and its structure is similar to that of an asynchronous motor.
When the three-phase AC power supply is connected to the stator winding, a rotating magnetic field is generated in the motor, and the squirrel cage winding cuts the magnetic lines of force to generate induced current, which makes the motor rotate. After the motor rotates, its speed slowly increases to a speed slightly lower than that of the rotating magnetic field. At this time, the rotor magnetic field coil is excited by DC to form certain magnetic poles on the rotor. These magnetic poles attempt to track the rotating magnetic poles on the stator, thus increasing the speed of the motor rotor until it rotates synchronously with the rotating magnetic field.
The synchronous motor whose rotor does not need excitation can be applied to single-phase power supply or multi-phase power supply. In this kind of motor, the stator winding of one kind is similar to that of a split phase motor or a polyphase motor. At the same time, there is a squirrel cage rotor, and the surface of the rotor is cut into a plane. Therefore, it belongs to a pole displaying rotor. The rotor pole is made of a kind of magnetized steel and can always maintain magnetism. The squirrel cage winding is used to generate the starting torque. When the motor rotates to a certain speed, the rotor pole will be synchronized with the current frequency of the stator coil. The polarity of the salient pole is induced by the stator, so its number should be equal to the number of poles on the stator. When the motor turns to its proper speed, the squirrel cage winding loses its function. To maintain the rotation, the rotor and the pole follow the stator pole to make it synchronized
Ho fanampin'ny maotera haingam-pandeha tsy tapaka, motera haingam-pandeha tsy tapaka, motera hafainganam-pandeha miovaova ary motera hafainganam-pandeha tsy miova, ny maotera hafainganam-pandeha miovaova dia azo zaraina koa amin'ny maotera hafainganam-pandehan'ny elektromagnetika, motera hafainganam-pandeha DC, motera hafainganam-pandeha miovaova PWM ary nivadika fisalasalana miovaova hafainganam-pandeha maotera.
Ny hafainganam-pandehan'ny motera asynchronous dia ambany kely noho ny hafainganam-pandehan'ny sahan'andriamby mihodina.
Ny hafainganam-pandehan'ny motera synchronous dia tazonina amin'ny hafainganam-pandeha synchronous foana na inona na inona enta-mavesatra.
Vidin'ny motera 5 hp 2 any India
DC tsy misy borosy
Brushless DC motor uses semiconductor switching devices to realize electronic commutation, that is, electronic switching devices are used to replace the traditional contact commutator and brush. It has the advantages of high reliability, no commutation spark and low mechanical noise. It is widely used in high-grade recording stands, video recorders, electronic instruments and automatic office equipment.
Brushless DC motor is composed of permanent magnet rotor, multi pole winding stator, position sensor, etc. Position sensing converts the current of stator winding in a certain order according to the change of rotor position (that is, detect the position of rotor magnetic pole relative to stator winding, generate position sensing signal at the determined position, control the power switch circuit after being processed by the signal conversion circuit, and switch the winding current according to a certain logic relationship). The working voltage of the stator winding is supplied by the electronic switch circuit controlled by the output of the position sensor.
There are three types of position sensors: magnetic sensor, photoelectric sensor and electromagnetic sensor. For brushless DC motor with magnetic position sensor, its magnetic sensor components (such as hall element, magnetic diode, magnetic transistor, magnetic resistor or special integrated circuit, etc.) are installed on the stator assembly to detect the change of magnetic field generated by the rotation of permanent magnet and rotor.
The brushless DC motor with photoelectric position sensor is equipped with photoelectric sensor at a certain position on the stator assembly. The rotor is equipped with a shading plate, and the light source is a light-emitting diode or small bulb. When the rotor rotates, the photosensitive components on the stator will generate pulse signals intermittently at a certain frequency due to the action of the shading plate.
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 permanent magnet rotor changes, the electromagnetic effect will cause the electromagnetic sensor to generate high-frequency modulation signal (its amplitude changes with the rotor position).
ambony
DC motor has fast response, large starting torque
From zero speed to rated speed, it can provide rated torque, but the advantage of DC motor is also its disadvantage, because DC motor needs to produce constant torque performance under rated load, the armature magnetic field and rotor magnetic field must be maintained at 90 °, which requires carbon brush and commutator. The carbon brush and commutator will generate sparks and carbon powder when the motor rotates. Therefore, in addition to causing component damage, the application occasions are also limited. AC motor has no carbon brush and commutator, so it is maintenance free, solid and widely used. However, to achieve the performance equivalent to that of DC motor, complex control technology must be used. Nowadays, with the rapid development of semiconductors, the switching frequency of power components is much faster, which improves the performance of drive motors. The speed of the microprocessor is also faster and faster, which can control the AC motor in a rotating two axis DC-AC coordinate system, and properly control the current component of the AC motor in the two axes, so as to achieve the control similar to the DC motor and have the same performance as the DC motor.
Vidin'ny motera 5 hp 2 any India
In addition, many microprocessors have done the necessary functions of controlling the motor in the chip, and the volume is becoming smaller and smaller; Such as analog to digital converter (ADC), pulse wide modulator (PWM), etc. Brushless DC motor is an application that controls the commutation of AC motor electronically, which has the characteristics similar to that of DC motor without the lack of DC motor mechanism.
rafitra fanaraha-maso
Brushless DC motor is a kind of synchronous motor, that is, the speed of motor rotor is affected by the speed of motor stator rotating magnetic field and the number of rotor poles (P):
n=120．f / p。 When the number of rotor poles is fixed, the rotor speed can be changed by changing the frequency of the stator rotating magnetic field. Brushless DC motor is a way to add electronic control (driver) to synchronous motor to control the frequency of stator rotating magnetic field and feedback the speed of motor rotor to the control center for repeated correction, so as to approach the characteristics of DC motor. In other words, the brushless DC motor can control the motor rotor to maintain a certain speed when the load changes within the rated load range.
The DC brushless driver includes a power supply unit and a control unit. The power supply unit provides three-phase power to the motor, and the control unit converts the input power frequency as required.
The power supply unit can directly input DC (usually 24V) or AC (110v/220 V). If the input is AC, it must first be converted to DC through the converter. Whether DC input or AC input is to be transferred to the motor coil, the DC voltage must be converted from the inverter to 3-phase voltage to drive the motor. The inverter is generally composed of 6 power transistors (Q1 ~ Q6), which are divided into upper arm (Q1, Q3, Q5) / lower arm (Q2, Q4, Q6) and connected to the motor as a switch to control the flow through the motor coil. The control unit provides PWM (pulse width modulation) to determine the switching frequency of power transistor and the timing of inverter commutation. The brushless DC motor generally wants to use the speed control that can stabilize the speed at the set value without too much change when the load changes, so the motor is equipped with a Hall sensor that can induce the magnetic field as the closed-loop control of speed and the basis of phase sequence control. But this is only used for speed control, not for positioning control.
Fitsipika mifehy
To make the motor rotate, the control unit must first determine the sequence of opening (or closing) the power transistors in the inverter according to the current position of the motor rotor sensed by the hall sensor, and then make the current flow through the motor coil in sequence to generate a forward (or reverse) rotating magnetic field, and interact with the magnet of the rotor, so that the motor can rotate clockwise / counterclockwise. When the motor rotor rotates to the position where the hall sensor senses another group of signals, the control unit turns on the next group of power transistors, so that the circulating motor can continue to rotate in the same direction until the control unit decides to stop the motor rotor, then turn off the power transistor (or only turn on the lower arm power transistor); If the motor rotor is reversed, the power transistor opening sequence is reversed.
Vidin'ny motera 5 hp 2 any India
Môtô tsy mihira
1、 AC asynchronous motor
AC asynchronous motor is a leading AC voltage motor, which is widely used in electric fans, refrigerators, washing machines, air conditioners, hair dryers, vacuum cleaners, range hoods, dishwashers, electric sewing machines, food processing machines and other household appliances, as well as various electric tools and small-scale electrical equipment.
AC asynchronous motor is divided into induction motor and AC commutator motor. Induction motor is divided into single-phase asynchronous motor, AC / DC motor and repulsion motor.
The speed of the motor (rotor speed) is less than the speed of the rotating magnetic field, so it is called asynchronous motor. It is basically the same as induction motor. s=(ns-n)/ns。 S is the slip rate,
Ny NS dia ny hafainganam-pandehan'ny sahan'andriamby ary ny N ny hafainganam-pandehan'ny rotor.
Fitsipika fototra:
1. When the three-phase asynchronous motor is connected to the three-phase AC power supply, the three-phase stator winding flows through the three-phase magnetomotive force (stator rotating magnetomotive force) generated by the three-phase symmetrical current and generates a rotating magnetic field.
2. The rotating magnetic field has relative cutting motion with the rotor conductor. According to the principle of electromagnetic induction, the rotor conductor generates induced electromotive force and induced current.
3. According to the law of electromagnetic force, the current carrying rotor conductor is affected by electromagnetic force in the magnetic field to form electromagnetic torque to drive the rotor to rotate. When the motor shaft is loaded with mechanical load, it will output mechanical energy outward.
Asynchronous motor is a kind of AC motor, and the ratio of its load speed to the frequency of the connected power grid is not constant. It also changes with the size of the load. The higher the load torque, the lower the rotor speed. Asynchronous motor includes induction motor, doubly fed asynchronous motor and AC commutator motor. Induction motor is the most widely used. It can generally be called asynchronous motor without causing misunderstanding or confusion.
Vidin'ny motera 5 hp 2 any India
The stator winding of ordinary asynchronous motor is connected to AC power grid, and the rotor winding does not need to be connected to other power sources. Therefore, it has the advantages of simple structure, convenient manufacture, use and maintenance, reliable operation, low quality and low cost. Asynchronous motor has high operating efficiency and good working characteristics. It operates at a constant speed from no-load to full load. It can meet the transmission requirements of most industrial and agricultural production machinery. Asynchronous motors are also easy to generate various protection types to meet the needs of different environmental conditions. When the asynchronous motor is running, the reactive excitation power must be drawn from the power grid to make the power factor of the power grid worse. Therefore, synchronous motors are often used to drive high-power and low-speed mechanical equipment such as ball mills and compressors. Because the speed of asynchronous motor has a certain slip relationship with its rotating field speed, its speed regulation performance is poor (except AC commutator motor). For transportation machinery, rolling mills, large machine tools, printing and dyeing and papermaking machinery requiring a wide and smooth speed regulation range, it is economical and convenient to use DC motors. However, with the development of high-power electronic devices and AC speed regulation system, the speed regulation performance and economy of asynchronous motor suitable for wide speed regulation are comparable to that of DC motor.
2、 Single phase asynchronous motor
Single phase asynchronous motor consists of stator
Rotor, bearing, casing, end cover, etc.
The stator is composed of frame and iron core with winding. The iron core is formed by punching and pressing silicon steel sheets into slots. Two sets of main windings (also known as operating windings) and auxiliary windings (also known as starting windings) with an electrical angle of 90 ° are embedded in the slots. The main winding is connected to AC power supply, and the auxiliary winding is connected to centrifugal switch s or starting capacitor, operating capacitor, etc. in series, and then connected to power supply.
The rotor is a cage type cast aluminum rotor. After the iron core is laminated, it is cast into the groove of the iron core with aluminum, and the end ring is cast together, so that the rotor guide bar is short circuited into a squirrel cage type.
Ny motera asynchronous dingana tokana dia mizara ho fanoherana tokana manomboka motera asynchronous, capacitor tokana manomboka motera asynchronous, capacitor tokana mandeha motera asynchronous ary capacitor asynchronous asynchronous dingana tokana.
