Is there a synchronous motor and what does synchronous and asynchronous mean?

There are synchronous motors. A synchronous motor is an electric motor that rotates exactly in the phase of a given signal (or power source). An asynchronous motor is a motor that does not rotate exactly in phase for a given signal (or power source).

The difference between synchronous motor and asynchronous motor:

Synchronous motor When the synchronous motor is overly running, reactive power is emitted, which is equivalent to reactive power supply; Absorbs reactive power during under-excitation operation, which is equivalent to reactive load. Usually the load of the power grid is inductive, so the synchronous motor is generally operated under normal excitation or over-excitation to improve the power factor of the power grid.

Asynchronous motor When the asynchronous motor works, only the stator is energized (three-phase alternating current), and the rotor is subjected to the induced current to produce a magnetic field (the principle is the same as that of the transformer), because it is an induced current, so when the magnetic field is rotated, it is necessary to lag behind the stator magnetic field by an angle, and when looking at the stator side, it is the stator magnetic field that drags the rotor to rotate. The rotational speed is lower than the synchronous rotational speed, so it is called an asynchronous motor.

Yes, the main difference between synchronous motors and asynchronous motors is whether the operation of the motor is consistent with the rotation speed of the magnetic field.

The magnetic field rotation speed of the synchronous motor is matched with the rotation speed of the motor, and they are synchronized. The magnetic field rotation speed of the asynchronous motor is not synchronized with the rotation speed of the motor, because the magnetic field rotation speed of the asynchronous motor is determined by the AC frequency of the power supply, and the rotation speed of the motor is determined by the interaction between the current and the magnetic field inside the motor.

Both synchronous and asynchronous motors are commonly used AC motors.

The characteristic of synchronous motors is that when running in a steady state, there is a constant relationship between the speed of the rotor and the frequency of the grid.

Rotational speed = 60 * power frequency number of poles of the motor. If the frequency of the grid is constant, the speed of the synchronous motor is constant at steady state, regardless of the size of the load.

An asynchronous machine is a motor in which the rotor rotates at a different speed than the rotation speed of the rotating magnetic field generated by the stator, and there is a difference (out of sync). We call it deterioration. The ratio of this slip to the rotational speed of the rotating magnetic field generated by the stator is called the slip rate.

The difference between a synchronous machine and an asynchronous machine is:

1. From the aspect of power supply, the asynchronous machine only adds voltage on the stator side (there is also a voltage on the rotor), while the synchronous machine needs to add voltage to both the stator and the rotor (the rotor of the permanent magnet synchronous motor relies on the permanent magnet to excite, and does not need to be energized to excite, so the rotor does not need to add voltage), that is to say, the asynchronous machine is unilateral excitation, and the synchronous machine is bilateral excitation.

Second, in terms of speed, the speed of the asynchronous machine is only related to the load size (of course, there is a certain range), while the speed of the synchronous machine is only related to the frequency of the power grid.

3. Structurally speaking, the structure of the rotor of the synchronous motor and the asynchronous machine is also different. The rotor of the asynchronous machine is composed of a steel sheet and an aluminum strip (or a steel sheet and a coil), while the synchronous machine is generally composed of several magnets or coils.

Of course, there are many differences, such as process requirements, design issues, and so on.

Hello landlord:

A synchronous motor is also a type of AC motor. It is mainly used for generators, but also for motors, and is generally used for production machinery with large power and speed that does not require adjustment, such as large water pumps, air compressors and mine ventilators. In recent years, due to the development of permanent magnet materials and electronic technology, micro synchronous motors have been more and more widely used.

One of the characteristics of synchronous motors is that there is a strictly constant relationship between the speed n during stable operation and the frequency f1 of the stator current, ie.

n=60f1/p=n0

The rotational speed n of the synchronous motor is the same as the rotational speed n0 of the rotating magnetic field. Hence the name "synchronicity".

Needless to say, the stator of the synchronous motor also needs to be energized to keep it synchronized with the stator. (The rotor of the micro synchronous motor can be made of permanent magnet magnets).

Asynchronous motors are different, the stator windings are energized to produce a rotating magnetic field, which induces a current in the rotor to rotate the motor. The structure is simpler than that of synchronous motors.

What is an asynchronous motor?

The asynchronous motor is an AC motor based on the interaction between the air-gap rotating magnetic field and the induced current in the rotor winding to generate electromagnetic torque, so as to realize energy conversion. Since the rotor winding current is induced, there is a certain difference between its rotational speed and synchronous rotational speed.

Difference Between Asynchronous Motor and Synchronous Motor:

The number of revolutions is fixed during normal operation of the synchronous motor and does not change due to the change of load.

The number of revolutions is not fixed during normal operation of the asynchronous motor, but will change slightly due to the change of load. Synchronous motors have complex circuits and reversible energy (motors and generators are theoretically interchangeable) and are mostly used as generators.

The speed of the rotor of the asynchronous motor is lower than the speed of the rotating magnetic field, and the rotor winding induces electromotive force and current due to the relative motion between the magnetic field and the magnetic field, and interacts with the magnetic field to generate electromagnetic torque to achieve energy conversion.

The rotational speed of the rotor of the synchronous motor motor and the rotational speed of the current of the stator are synchronized.

1. The difference between synchronous motor and asynchronous motor: different starting methods, different structures, and different power supplies.

1. Different starting methods:

Synchronous motor: To start the synchronous motor, other methods must be used, mainly the following two methods, asynchronous starting method; Auxiliary motor starting method.

Asynchronous motor: three methods, 1, soft start 2, direct start 3, buck start.

2. The structure is different

The stator windings of synchronous and asynchronous motors are the same, with the main difference being the structure of the rotor.

Synchronous motor: There is a DC excitation winding on the rotor, so an external excitation power supply is required to introduce the current through the slip ring.

Asynchronous motors: The rotor is a short-circuited winding that generates current by electromagnetic induction. In contrast, synchronous motors are more complex and expensive to build.

3. The power supply is different

Asynchronous motor: only the voltage is added on the stator side (there are also voltages on the rotor), and the asynchronous motor is unilateral excitation.

Synchronous motors: Voltage is added to both the stator and the rotor. The synchronous motor is bilaterally excited and runs on the excitation current.

Second, the use of synchronous motors and asynchronous motors.

1. Synchronous motor: mostly used in large generators. When selecting motors above 2000kw, synchronous motors should generally be considered.

2. Asynchronous motor: almost all used in electric airports. For motors below 2500kw, most of them choose asynchronous motors.

Synchronous motors are used to generate electricity.

Asynchronous motors are used on electric motors.

1. The difference between the design of synchronous motor and asynchronous motor.

The biggest difference between synchronous motor and asynchronous motor is whether their rotor speed is consistent with the stator rotating magnetic field, the rotor speed of the motor is the same as the stator rotating magnetic field, which is called synchronous motor, and vice versa, it is called asynchronous motor.

In addition, the stator windings of synchronous motors and asynchronous motors are the same, the difference is in the rotor structure of the motor. The rotor of an asynchronous motor is a short-circuited winding that generates an electric current by electromagnetic induction. The rotor structure of the synchronous motor is relatively complex, with DC excitation winding, so it needs to add an external excitation power supply to introduce current through the slip ring; Therefore, the structure of the synchronous motor is relatively complex, and the cost and maintenance cost are relatively high.

2. The difference between synchronous motor and asynchronous motor in terms of reactive power.

Compared with asynchronous motors, which can only absorb reactive power, synchronous motors can emit reactive power and can also absorb reactive power!

3. The difference between synchronous motor and asynchronous motor in terms of function and use.

The speed of the synchronous motor is synchronized with the electromagnetic speed, and the speed of the asynchronous motor is lower than the electromagnetic speed, regardless of the load size of the synchronous motor, as long as it does not lose step, the speed will not change, and the speed of the asynchronous motor will always change with the change of the load size.

The synchronous motor has high precision, but the construction is complex, the cost is high, and the maintenance is relatively difficult, while the asynchronous motor is slow to respond, but it is easy to install and use, and at the same time it is cheap. Therefore, synchronous motors are not as widely used as asynchronous motors.

Synchronous motors are mostly used in large generators, while asynchronous motors are almost used in electric airports.

1. The difference between motor synchronization: the speed of the synchronous motor is synchronized with the electromagnetic speed, and the speed of the asynchronous motor is lower than the electromagnetic speed.

2. Structural differences: synchronous motors have high precision, but complex manufacturing, high cost, and relatively difficult maintenance, while asynchronous motors are slow to respond, but easy to install and use, and cheap at the same time. Therefore, synchronous motors are not as widely used as asynchronous motors.

3. Difference in use occasions: synchronous motors are mostly used in large generators, while asynchronous motors are almost used in electric airports.

4. The main difference between synchronous motor and asynchronous motor lies in whether there is slippage (the difference between the speed of the magnetic field and the speed of the rotor).