Synchronous and asynchronous motor: differences, principle of operation, application

The Classification engines are based on different parameters. One of them, distinguish between synchronous and asynchronous motor. Differences of devices, General characteristics and operation are described in the article.

Synchronous motor

This type of motor is capable to operate simultaneously as a generator, and, in fact, the engine. His device is akin to a synchronous generator. A characteristic feature of the engine is the invariant frequency of rotor rotation from load.

These types of motors are widely used in many fields, for example, electrical wires that require constant speed.

Working Principle of synchronous motor

The basis of its operation is necessary the interaction of the rotating magnetic field of the armature and the magnetic field of the inductor poles. Usually the anchor is in the stator, and the inductor placed in the rotor. For powerful motors use electric magnets for poles, and for the weak — constant.

The Principle of operation of a synchronous motor includes a (short-time) and asynchronous mode, which is usually used for acceleration to the required (i.e. rated) speed. At this time, the inductor winding is short-circuited or closed through the rheostat. After reaching the required speed, the inductor begin to be powered by a constant current.

Advantages and disadvantages

The Main disadvantages of this engine are:

• The need to field supply a constant current;
• The complexity of your startup;
• Sliding contact.

Most of the generators wherever they are used, are synchronous. Advantages of such engines in General are:

• Reliability;
• The biggest efficiency;
• Easy maintenance.

Asynchronous motor

This device is a mechanism aimed at transforming electrical energy from AC to mechanical. From the title “induction”, we can conclude that we are talking about non-simultaneous process. Indeed, the rotation frequency of the magnetic field of the stator above the rotor always here.
This device consists of a stator of cylindrical shape and the rotor, depending on which squirrel-cage induction motors may be wound rotor.

Principle of operation

The engine is based on the interaction between the magnetic stator field and suggestive of the same field currents in the rotor. Torque appears when there is a difference between the rotation frequency of the field.

Now to sum up, what distinguishes synchronous from asynchronous motor. What explains the wide use of one type and a limited — another?

Synchronous and asynchronous motor: differences

The Difference engine - the rotor. In a synchronous type it is permanent or electric magnet. Due to attraction of opposite poles of the rotating field of the stator leads and a magnetic rotor. The speed turns out the same. Hence the name — synchronized.

It is possible to achieve, in contrast to asynchronous, even ahead of the voltage phase. Then a device similar to a battery the capacitor can be used to increase the power.

Asynchronous motors, in turn, simple and reliable, but their disadvantage is the difficulty of adjusting the speed. To reverse three phase asynchronous motor (that is, changing the direction of rotation in the opposite direction) change the location of the two phases, or two line wires approaching the stator windings.

If we consider speed, we have here the synchronous and asynchronous motor differences. In a synchronous type, this rate is permanent, in contrast to asynchronous. Therefore, the first use that needs full speed and full control, for example, in pumps, fans and compressors.

To Identify a particular device, the presence of the considered types of devices very simple. The induction motor will not round the number of revolutions (for example, nine hundred and thirty per minute), while for synchronous — round (for example, a thousand revolutions per minute).

Those And other motors are driven quite hard. The synchronous type has a rigid characteristic mechanics: whenever changing the load on the motor shaft rotational frequency will be the same. While the load, of course, must change given the fact that the motor is able to withstand, otherwise it will lead to breakagemechanism.

So arranged synchronous and asynchronous motor. The differences of both species determine the scope of their use when one kind of job in an optimal way, for another, it will be problematic. At the same time can be found and combined mechanisms.