October 19, 2020 Synchronous Motors and Generators

The function and uses of synchronous motors.

Currently, a large collection of synchronous motors and generators is available with a wide range of industrial applications. Electric motors have become an integral part of industrial production. They convert electrical energy into mechanical energy, enabling industrial machines to perform the tasks assigned to them. Not all electric motors perform a similar set of tasks, but some of them are specifically designed for a particular industry.

Applications in the Industrial Field

Apart from the many different functions facilitated by carefully designed motors, the tasks performed in the industry are perhaps the most complicated. Some electric motors are used in coal mining, while some motors provide the energy for crushing and shredding in the cement industry. For steel mills, on the other hand, a stable input is required to ensure the continuity of their production process in an extremely warm atmosphere. For this reason, they often use special motors for conveyor belts. The sugar industry relies on customized high-voltage motors or the IE4 super premium motors, as these can provide a higher voltage without requiring much electrical energy.

Applications in Production Machines

Electric motors are used not only to supply fields and equipment but also to drive a whole range of production machines. The motors underneath are the ones that drive a propeller, turn up a turbine or suck in smoke and debris in a crowded public or private environment. In waterworks, it is the electric motors that help to pump up the water. In addition, there are advanced three-phase electric motors that are used in compressors because they can cool themselves sufficiently and thus withstand higher temperatures. These advantages also make them a perfect choice for industrial boilers.

In electrical systems such as those we use either in industry, power stations, or in private households, motors and generators have become an everyday device. With the demand for systems with high energy efficiency and lower power consumption, the invention of new models of these electrical devices can be observed. The basic calculation factor for the reliable operation of motors and generators is the power factor. It is the ratio of the power applied to the power required. Usually, the total power consumed in industries and factories is calculated on the basis of the power factor. The power factor should therefore always be kept at a uniform value. However, due to the increase in reactive power in these devices, the power factor decreases. Many methods are introduced to keep the power factor at a uniform value. The concept of the synchronous motor is one of them.

The Synchronous Motor: What is it?

This is how a synchronous motor is defined: An alternating current motor in which, in the stationary state, the rotation of the shaft is synchronous with the frequency of the applied current.

A synchronous motor does not work with an induction current. Unlike induction motors, these motors have multi-phase AC magnets on the stator that generate a rotating magnetic field. In this case, the rotor has a permanent magnet that is synchronous with the rotating magnetic field and rotates synchronously with the frequency of the current supplied.

The functionality of a Synchronous Motor

The function of synchronous motors is based on the interaction of the magnetic field of the stator in combination with the magnetic field of the rotor.  3-phase windings are included in the stator and are operated with a 3-phase current. The stator winding thus generates a three-phase rotating magnetic field. The rotor is supplied with a direct current.

If the load is greater than the breakdown load, the motor is desynchronized. The 3-phase stator winding offers the advantage that it determines the direction of rotation. With single-phase winding it is not necessary to determine the direction of rotation and the motor is able to start in both directions. Starting devices are necessary for controlling the direction of rotation in these synchronous motors.

Usage Areas of Synchronous Motors

Synchronous motors are normally used in applications in which a constant and precise speed is required. Typical applications of these low power motors are positioning machines. They are also used in robot actuators. Synchronous motors are also used in ball mills, watches, record players, and turntables. They are also used as servo motors and timing machines.

Such motors are available in a range from horseshoe size to industrial high performance size. Although they are used in industrial high performance sizes, these motors are able to perform two essential functions. One is as an efficient means of converting alternating current energy into mechanical energy and the other is as a power factor correction.

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