Minimization of Losses in Induction Motors Powered by Frequency Converters

In a self-ventilated electric induction motor fed by a static frequency converter, the moment of its application is thermally critical, as the motor losses vary slightly depending on the rotation, therefore having the fan coupled to the motor shaft, Causes the ventilation effect to decrease as the rotation drops.

When operated at low engine speeds, this engine causes its temperature to rise due to lack of ventilation, and in order to get around the problem, the industry has used one of two solutions: independent ventilation, where a small auxiliary motor is used exclusively to power the engine. Fan cooling the main motor; Or over-dimensioning, where an engine more powerful than the one needed to power the load, is used in the application. The two solutions do not become attractive because they increase the space required in the installation and also increases the price.

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Usually the frequency converters cause the motor to have a constant voltage / frequency ratio over the entire operating range, with no loss control. The study of the composition of these losses and their relationship with voltage, frequency, magnetic flux and current, together with the influence of the ventilation on the elevation of temperature of the motors, allows to determine this relation. This incorporates the automatic voltage / frequency ratio control feature in the inverter.

Three-phase electric motor speed and its slip

The induction electric motor starts operating normally at a speed that is always constant, because it is motivated by the rotating magnetic field and its name is synchronous speed and in function of two factors that are: magnetic poles generated as a function of their physical construction And frequency of the electrical network to which the electric motor is installed.

Therefore, the induction electric motor speed0 is directly proportional to frequency and inversely proportional to the number of magnetic poles.


The electric motor can also suffer from the process called slipping. In it, some factors are responsible for causing the actual speed at the axis of the electric motor to cease to be exactly the speed of the rotating magnetic field.

The three-phase electric motor naturally has a difference between its spinning magnetic field velocity (ns) and the actual speed in its rotor (N) and this occurs due to a phenomenon called slippage and is supplied by the electric motor manufacturer Which will vary from one electric motor to another.

Electric Motor Protection

Electrical motor nameplate indicates what is your degree of protection against foreign body input

The nameplate which is affixed to the electric motor must contain all the peculiar characteristics of the electric motor.

The nameplate of the electric motor is also used to indicate the power of the electric motor in KW and CV. The RPM indicates the nominal speed of the electric motor. The ISOL is on the nameplate of the electric motor to indicate which is the insulation class of the electric motor coil. If the class indicated is F, this means that the coil of the electric motor supports operating at a temperature that reaches up to 105 degrees.

There are also others that the electric motor hose reels can operate and they are: class E up to 120 degrees; Class B up to 130 degrees; Class b and c up to 130 degrees; Class F minus 155 degrees and class H that supports up to 180.

The IP55 is on the nameplate of the electric motor to indicate the degree of protection of the electric motor in front of the penetration of bodies considered in its interior such as dust and liquids. There are models of electric motor that has the IP55 that has full protection against any body that invades its interior.

Necessary care with the maintenance of the electric motor

The electric motor is a device widely used in industries and therefore it is common to have a huge amount of services for workshops that perform the maintenance of the electric motor.

When looking for maintenance for an electric motor you need to be extremely attentive when the company that was hired and you need to know if the electric motor workshop has the best ways to run the service quickly but without forgetting the quality.

In order for the electric motor wpled26 to be maintained with agility, the service provider must have its own fleet of vehicles in order for the electric motor to be withdrawn and returned as soon as possible.

The service performed in this way will also ensure greater practicality without losing the quality of service and this will please the consumer who needs the maintenance of the electric motor.

When subjecting the electric motor to maintenance, it is necessary to verify if the professional knows and is up to date with the most sophisticated equipment on the market.

Electric motor how to use correctly

The correct use of the electric motor is related to the complete use of this machine. The function of the motor is to make the transformation from electrical energy to mechanical energy, this transformation is made based on the principles of electromagnetism and inside the internal structure of the machine we have parts that are specific for this to occur.

The single-phase and three-phase electric motor are the two models that you find available in the market. The single-phase motor is suitable for simple applications, while the three-phase model is suitable for more complex applications. To get an idea, the three phase model is the one used by the industrial segment, while the single phase model is the one used in home appliances. skf bearing products

Before making the purchase of the engine it is important that you know which of the models will fit what you need. Finding the ideal electric motor model for your application is very important, be sure to be analyzing all of these issues before you make your decision.

Alternating current electric motor operation

How does the AC motor work? What are the characteristics of this machine used in the industrial sector? Get to know!

The three-phase electric motor is the most used because of the distribution of electric energy that occurs through alternating current and also motivated by simplicity, robustness and low cost, being suitable for use in almost all types Of found machines, mainly In the industrial branch.

The ever-constant speed of the three-phase electric motor can vary depending on some factors such as loads that are applied to your shaft. The principle of operation of this electric motor is based on the rotating magnetic field, which arises when there is a three-phase alternating current system that is applied at poles that are physically lagged 120 degrees.

In this way, the magnetic field in each set of coils of the electric motor arises through this lag, and these magnetic fields are generated when they form what is called the rotating magnetic field.