Created at the end of the 19th century, the three-phase asynchronous motor has become an indispensable component of modern industrial production.

For soft start and stop of such equipment, a special device is required - a frequency converter. The presence of a converter for large engines with high power is especially important. With the help of this additional device, it is possible to regulate the starting currents, that is, to control and limit their magnitude.

If you regulate the starting current exclusively mechanically, you will not be able to avoid energy losses and reduce the life of the equipment. The indicators of this current are five to seven times higher than the rated voltage, which is unacceptable for the normal operation of the equipment.

The principle of operation of a modern frequency converter involves the use of electronic control. They not only provide a soft start, but also smoothly regulate the operation of the drive, adhering to the ratio between voltage and frequency strictly according to a given formula.

The main advantage of the device is the saving in electricity consumption, which averages 50%. As well as the ability to adjust to the needs of a particular production.

The device operates on the principle of double voltage conversion.

1. rectified and filtered by a system of capacitors.
2. Then the electronic control comes into operation - a current is generated with a specified (programmed) frequency.

At the output, rectangular pulses are produced, which, under the influence of the motor stator winding (its inductance), become close to a sinusoid.

What to look for when choosing?

Manufacturers focus on the cost of the converter. Therefore, many options are available only for expensive models. When choosing a device, you should determine the basic requirements for a particular use.

• The control can be vector or scalar. The first allows fine adjustment. The second only maintains one, given ratio between frequency and output voltage and is suitable only for simple devices, such as a fan.
• The higher the specified power, the more versatile the device will be - interchangeability will be ensured and equipment maintenance will be simplified.
• The mains voltage range should be as wide as possible, which will protect against changes in its norms. A downgrade is not as dangerous to the device as an upgrade. With the latter, network capacitors may well explode.
• The frequency must be fully consistent with the needs of production. The lower limit indicates the speed control range of the drive. If a wider one is needed, vector control is required. In practice, frequencies from 10 to 60 Hz are used, less often up to 100 Hz.
• The control is carried out through various inputs and outputs. The more of them, the better. But a larger number of connectors significantly increases the cost of the device and complicates its configuration.

Discrete inputs (outputs) are used to input control commands and output messages about events (for example, about overheating), digital inputs - to input digital (high-frequency) signals, analog - to input feedback signals.

• The control bus of the connected equipment must match the capabilities of the frequency converter circuit in terms of the number of inputs and outputs. It is better to have a small margin for upgrading.
• overload capacity. It is optimal to choose a device with a power of 15% more than the power of the engine used. In any case, read the documentation. Manufacturers indicate all the main parameters of the engine. If peak loads are important, a drive with a peak current rating of 10% greater than the specified value should be selected.

Do-it-yourself frequency converter assembly for an asynchronous motor

You can assemble an inverter or converter yourself. Currently, there are many instructions and diagrams for such an assembly on the network.

The main task is to get a "folk" model. Cheap, reliable and designed for domestic use. For the operation of equipment on an industrial scale, of course, it is better to give preference to devices sold by stores.
The procedure for assembling a frequency converter circuit for an electric motor

For work with domestic wiring, with a voltage of 220V and one phase. Approximate engine power up to 1 kW.

On a note. Long wires must be provided with interference suppression rings.

Adjustment of the rotation of the motor rotor fits in the frequency range of 1:40. For low frequencies, a fixed voltage is required (IR compensation).

Connecting the frequency converter to the electric motor

For single-phase wiring at 220V (use at home), the connection is made according to the "triangle" scheme. The output current must not exceed 50% of the nominal!

For three-phase wiring at 380V (industrial use), the motor is connected to the frequency converter according to the “star” scheme.

The transmitter (or ) has corresponding terminals marked with letters.

• R, S, T - network wires are connected here, the order does not matter;
• U , V , W - to turn on the asynchronous motor (if the motor rotates in the opposite direction, you need to swap any of the two wires on these terminals).
• There is a separate ground terminal.

To extend the life of the inverter, the following rules must be observed:

1. Regularly clean the inside of the device from dust (it is better to blow it out with a small compressor, since a vacuum cleaner will not always cope with pollution - the dust is compacted).
2. Replace nodes in a timely manner. Electrolytic capacitors are designed for five years, fuses for ten years of operation. And cooling fans for two to three years of use. Internal plumes should be replaced every six years.
3. Monitor internal temperature and DC bus voltage.

An increase in temperature leads to the drying of the thermally conductive paste and the destruction of capacitors. On the power components of the drive, it should be changed at least once every three years.

4. Adhere to the operating conditions. The ambient temperature should not exceed +40 degrees. High humidity and dust content of the air is unacceptable.

Controlling an asynchronous motor (for example,) is a rather complicated process. Handicraft converters are cheaper than industrial counterparts and are quite suitable for domestic use. However, for industrial applications, it is preferable to install factory-assembled inverters. Maintenance of such expensive models can only be done by well-trained technical personnel.

19 02.2017

In addition to the common 3-phase asynchronous motors, single-phase motors are offered on the market. Most often they are pumps and fans. The most popular units in industry and at home. And then the question arises? How do you control them and adjust the speed. There are a great many ways. But the most effective is when a frequency converter is connected for a single-phase motor.

From this article you will learn:

Hello! Gridin Semyon is with you, and in this post we will talk with you about the nuances of controlling asynchronous single-phase motors. What is the best way to manage? Let's analyze such a question - frequency control of the engine in more detail.

Single phase asynchronous motor

Such motors have found the greatest application in everyday life and small businesses. They are needed where there is no three-phase network. Their power is limited only by the frequency of the network. The devices themselves are low-power, ranging from 500 watts to 2 kilowatts.

The principle of operation of a single-phase motor is to shift the windings in space relative to each other. The key point is the phase shift in the windings by 120 degrees. The main "phase shifter" we have is a capacitor. As a rule, it is connected in series in the stator winding circuit.

Engine designs may vary. So, not everyone can connect a frequency converter, you need to pay attention first of all to the winding connection diagram. A two-phase motor with a working and starting winding will definitely not be able to start, a completely different principle of operation. We'll get back to this...

Motor connection methods

Now let's look at several ways to connect:

• capacitor method;
• frequency method;
• phase control with a triac;

Which way is best? You know, it all depends on the task that needs to be solved... But the taste and color, you know...

If you are not familiar with the frequency converter, you can read the article ""

Capacitor connection method

Budgetary connection of three-phase motors to a single-phase network. We simply hook the capacitor in series in the winding circuit and turn the device from three-phase to single-phase. Here is the diagram:

Cn is the start capacitor and Cp is the run capacitor. In this case, I will not describe how to select a container. There is a wealth of information on the internet about this.

Phase control with a triac

This is one of the oldest methods of control. Two motor windings are connected in parallel, one of them with a capacitor. We connect a triac regulator to the winding points. Their relevance, in my opinion, has not yet disappeared. Best used for light loads (fans, pumps).

Important! Please note that sim. blocks are mainly designed for active load. Since the motor is an inductive load, we divide the active current by about 10. If the active load current is 50, then the inductive will be 5.

At the output of the device, a mains frequency voltage of 50 Hz is formed and the root mean square number is adjusted. Thus, we change the time of the open state of the triac for the voltage repetition period. The only drawback: the torque on the shaft drops relative to the decrease in voltage. Here is an example of Autonics SPK1:

Inputs for speed control are universal. Here you can connect a potentiometer of 1 kOhm, and a sensor with a current signal of 4-20 mA, and a voltage of 0-5 V.

frequency method

It makes no sense to talk about the popularity of the frequency converter. Since this device has long been known to everyone. The frequency method is the main one in our 21st century. The speed is controlled by PWM modulation. A fairly complex device that requires a separate article. According to the input voltage, there are both 380 V and 220 V. But what is the output?

There are ready-made options on the market for both single-phase and three-phase electric motors. Just need.

But, there are times when an inverter with a single-phase output is not affordable. Or you have a three-phase inverter on your shelf. Let's consider the option of connecting the motor to the frequency converter.

Connecting the frequency converter and single-phase motor

This scheme has a number of significant drawbacks:

1. The engine starts at a minimum frequency of 30 Hz;
2. The frequency below 30 Hz can be adjusted, but not recommended, very harmful to the engine;
3. There is a nuance with setting the starting voltage, you need to slightly coarsen the parameter;

To solve the issue of connecting two devices, a regular choke will help us. The inductor will help us suppress the capacitance in the circuit, thus allowing the frequency converter to calmly feed a sinusoid to the engine. Yes, here is the diagram:

Everything is elementary, really. Video, unfortunately not saved. I post a photo with an Eaton inverter and a single-phase pump.

There are a lot of inverter manufacturers in the world. Therefore, from the settings, I can guide you approximately and in general terms if there are problems with connections. The main idea is that when starting the engine, the minimum voltage and frequency should be raised up. But it needs to be done carefully and carefully, there is a chance to burn the motor.

That's all for me, my friends...

I really enjoy cycling. Even more - to modernize, add something new and interesting. I recently found a set of an electric motor for the rear wheel on the Internet. Kits exist, both for the front wheel and for the rear:

I got the idea to put it on my bike. Can anyone come across? Someone set? I want to see your opinion... Write in the comments.

I hope my article helped you decide on the choice of connecting a single-phase motor? If something is not added, write in the comments, I will correct ...)

P.S. A small preview of the next article:

The widespread availability of photographic devices has created a new problem - the need for efficient digital editing tools. This market is traditionally dominated by the professional graphics package Adobe Photoshop. But, you should not limit your horizons only to them. There are a huge number of decent photo editors that cover 90% of the daily needs of amateur photographers.

Thanks for reading my articles! All the best!!

Sincerely, Gridin Semyon

To connect a chastotnik to an asynchronous three-phase motor, you should at least at a minimum level understand the scheme of its connection and the principles of operation. The following information allows you to study this topic.

Motor control principle

The rotor of an electric motor functions due to the rotation of electromagnetic fields under the stator winding. The speed of the rotor is dependent on the industrial frequency of the supply network.

Its standard value is 50 Hz and causes, respectively, fifty oscillatory periods per second. Within a minute, the number of revolutions increases to three thousand. Just as often, the revolutions of the rotor exposed to electromagnetic fields are carried out.

When the level of the frequency applied to the stator changes, it becomes possible to control the rotational speed of the rotor and the drive connected to it. It is thanks to this principle that the electric motor is controlled.

Classification of frequency converters

According to their design differences, the models are divided into:

Induction.

This includes electric motors having an asynchronous principle of operation. These devices do not have a high level of efficiency and significant efficiency. Due to these qualities, they do not have a large share in the total number of converters and are rarely used.

Electronic.

Suitable for smooth speed control in asynchronous and synchronous machines. Management in electronic models can be done in two ways:

Scalar (according to previously entered parameters of the interdependence of rotational V and frequency).

The simplest approach to control, rather imprecise.

Vector.

A distinctive characteristic is the accuracy of control.

Frequency converter vector control

The principle of operation of the vector control is as follows: it affects the magnetic flux, changing the direction of its "space vector" and regulating the rotor frequency of the field.

There are two ways to create a working algorithm for a vector-controlled frequency converter:

Sensorless control.

It is carried out by assigning interleaving dependencies between sequences of pulse-width modulation of the inverter for pre-compiled algorithms. The amplitude size and output frequency that the voltage has are adjusted according to the slip and load current, but the feedback from the rotary rotational speed is not taken into account.

Flow control.

The operating currents of the device are adjustable. At the same time, they are decomposed into an active and reactive component. This facilitates the possibility of making corrective changes to the workflow (changing the amplitudes, frequencies, vector angles that the output voltage has).

Helps improve accuracy and range. This approach is very relevant for a device with low revolutions and a high level of motor loads.

In general, the vector control scheme is more suitable for dynamically adjusting the torque of a three-phase asynchronous motor.

Connecting transistor switches

All six IGBTs are connected to their respective flyback diodes in an anti-parallel circuit. After that, the active current of the asynchronous motor passes through the power connection circuit formed by each transistor, followed by the direction of its reactive component through the diodes. In order to ensure the safety of the inverter and the asynchronous motor from the effects of third-party electrical interference, the design of the frequency converter may include noise filters. If industrial DC sources have an operating voltage of 220 V, they can also be used to power inverters.

How to connect a frequency converter to an asynchronous motor?

Used for control, it is often used to power three-phase motors. With the help it is also possible to ensure the connection of such a device to a single-phase network, preventing a decrease in its operating power. In this way, they significantly outperform capacitors, which, when connected, cannot maintain the original power level. For more information about the use of a three-phase frequency converter, see.

When connecting a frequency converter, it is necessary to first place a circuit breaker that operates from the mains current at a value equal to the rated (or closest to it) level of current consumption in the motor. If a three-phase type chastotnik is used, then, accordingly, a three-phase machine with a common lever should be used. This option provides a quick de-energization of all phases immediately when one of them is shorted.

The tripping current, according to its characteristics, must coincide with the single-phase current of the electric motor.

In the event that a single-phase power supply is typical for a frequency converter, then a single automatic machine should be used, which is suitable for working with triple single-phase current.

However, under any circumstances, the installation must not be carried out by turning on the machine at the point of breaking the neutral or ground wires. In such conditions, only direct switching on of the machine is implied.

Further tuning of the frequency converter is carried out through the connection with the contacts of the electric motor. In this case, phase wires are used. But beforehand, the windings of the electric motor are connected according to the “star” or “triangle” scheme.

Work according to one or another scheme is based on what type of frequency converter is and the nature of the voltage it produces.

According to the standard, the case of each motor has a mark with two values, which can be equal to the voltage. If the chastotnik produces a voltage corresponding to the lower limit, then the connection is made according to the “triangle” type. In other cases, use the "star" principle.

The location of the control panel, which must be included with the purchase of the frequency converter, should be chosen carefully to ensure the greatest convenience of use.

The control panel is connected according to the scheme indicated in the instructions attached to the converter. After the handle is fixed at the zero level, and the machine turns on. At this point, the indicator light should be lit.

To use the frequency converter, press the "RUN" button (it is already programmed properly). Next, a slight turn of the handle is made, provoking the start of a gradual rotation of the electric motor. If the rotation is carried out in the opposite direction to the desired one, then you should press the reverse. After that, using the handle, the required speed of the device is adjusted. In this case, it should be borne in mind that the control panel case often contains not levels expressed in revolutions per minute, but the frequency that the supply voltage has, expressed in hertz.

In order to limit the starting current and reduce the starting torque at the moment of starting an asynchronous motor with a power level greater than 5000W, a star-delta connection is used. Before reaching the nominal speed, the “star” frequency converter connection circuit is activated, and after that, the power is supplied according to the “triangle” circuit. At the moment of switching, the level of the starting current is reduced by a factor of three relative to the direct start. At the beginning of work according to the second scheme, until the moment of acceleration of the motors, the current will increase to the level of direct start. This option is most relevant for those with a large flywheel mass, allowing you to relieve the load after acceleration.

It is logical that the use of such a scheme is possible only with motors designed for both types of connections.

Carrying out work according to the "star-delta" scheme is always fraught with sharp jumps in the current level, as opposed to a smooth increase in direct starting conditions. At the moment of changing the connection, the speed drops sharply and it can be increased only by increasing the current strength.

Electric motors, including three-phase asynchronous ones, are widely used in various fields of activity. The operating cycle of the units is associated with their smooth start and a similar way of stopping. To solve the problem of controlling the frequency of the current and the speed of the motor, frequency converters are used.

Purpose and dignity

Electromagnetic forces generated under the influence of the magnetic field created by the armature winding set the rotor in motion. Its rotation occurs with the number of revolutions, which is set by the frequency of the mains current. At a frequency of 50 Hz, 50 oscillations occur within 1 s. Therefore, the rotor speed will be 3000 rpm.

The purpose of frequency converters is to provide effective motor control by changing the frequency parameters of the current.

The advantages of these devices are:

• ensuring the smooth operation of the motor at the time of starting and braking;
• regulation of the operation of engines assembled in a group;
• no need to use gearboxes and other mechanical devices to control the speed of the engine;
• ensuring the operation of drive control systems on a multifunctional basis;
• the possibility of adjustments in settings without interrupting the operation of the unit.

Device types

Depending on the design features, the main types of frequency converters 220/380 are distinguished - induction and electronic. The first option includes asynchronous varieties of electric motors, a feature of which is the use of a circuit with a phase rotor.

At the same time, they have the ability to work in generator mode. However, they are not very common in practice, since they have low efficiency and low efficiency.

But the electronic version can be used both in the operation of asynchronous engines, and modifications of the synchronous type. Engines are controlled in several fundamentally different ways:

Through scalar control, based on linear patterns. In this case, the proportional dependence of the amplitude on frequency is taken into account. If the frequency changes, then the amplitude of the input voltage will also change. As a result, this affects torque, efficiency, and power levels.

Setting the uniformity of the load moment is ensured by the constancy of the ratio of the amplitude to the output frequency. The transforming device also forms the specified equilibrium.

With the vector approach, the load moment is constant for any range of frequency changes. This allows for greater control accuracy. The flexibility of the drive response to jumps in the output load also increases. The frequency converter for an asynchronous motor provides constant control over the torque.

It is important to remember that the phase of the stator current, which changes under the influence of a magnetic field, is the current vector. It controls the torque. Thus, in this case, an amplitude or pulse-width signal adjustment system is used.

Design

There are different types of frequency converters for motors. But at the same time, separate typical blocks can be structurally distinguished. These components are closely related. The control unit determines the operation of the output stage.

In this case, the decisive role is played by the possibility of changing the parameters of the AC type current. Additionally, the device provides protection systems controlled by the microcontroller.

The rectifier is the first module. Current flows through it. This is where the alternating current takes place. With the help of diodes, it is converted to constant. You can choose models for a single-phase network or for a three-phase supply. They will have a different number of diodes.

DC voltage with high ripple comes out of the rectifier. To smooth out the ripples, a capacitor and an inductive coil are used. But the process of converting the parameters of the output current takes place in the inverter.

Structurally, it contains transistors. There are 6 of them - a pair for each phase. And the microprocessor system guarantees the control of the speed indicators of the rotary rotation. All this can be seen in the photo of the frequency converter.

Connection Features

Devices designed for frequency control can operate with a single-phase connection type or with a three-phase power supply. When operating DC sources that have a voltage of 220 V, they can also be used to connect inverters.

Modifications of the three-phase type are focused on the mains voltage of 380 V. They direct it to the engine. Single-phase inverters are powered from a 220 V network. At the output, they create three phases, which are distributed according to the time parameter.

If you are interested in the question of how to connect a frequency converter, then two circuit diagrams can be distinguished. According to the “star” principle, the windings are equipped for the converter, which is powered from a network with a voltage of 380 V. If the connection goes to a single-phase network of 220 V, then the “triangle” scheme is used.

In this case, the parameter of matching the motor power with the capabilities of the inverter should be taken into account. The inverter must not be overloaded. On the contrary, it is advisable to have some power reserve.

At the first stage of connection, a circuit breaker with a rating that matches the operating characteristics of the current consumed by the motor is mounted in front of the device. If the instruction on how to set up the frequency converter has been fully observed, then the phase conductors are connected to the specified motor contacts.

The conversion device must be connected to the controller. You also need to connect to a remote control. First, check the position of the handle - neutral. Then you need to start the machine. When the process complies with the standards, a light indication is observed.

A small turn of the handle will activate the rotation of the motor. The reverse button allows you to set the reverse direction of rotation. To set the desired frequency, you should adjust the knob. Subsequently, the operation of the converter will allow more efficient operation of equipment with an electric motor.

Photo of frequency converters

Content:

Three-phase asynchronous motors have found the widest application in industry and other areas. Modern equipment is simply impossible to imagine without these units. One of the most important components of the working cycle of machines and mechanisms is their smooth start and the same smooth stop after the task is completed. This mode is provided by using frequency converters. These devices have proved to be most effective in large electric motors with high power.

With the help of frequency converters, starting currents are successfully adjusted, with the ability to control and limit their magnitude to the desired values. For the correct use of this equipment, it is necessary to know the principle of operation of the frequency converter for an asynchronous motor. Its use can significantly increase the service life of equipment and reduce energy losses. Electronic control, in addition to soft start, provides smooth adjustment of the drive in accordance with the established ratio between frequency and voltage.

What is a frequency converter

The main function of frequency converters is the smooth adjustment of the speed of rotation of asynchronous motors. For this purpose, a three-phase voltage with a variable frequency is created at the output of the device.

Frequency converters are often . Their basic principle of operation is to rectify the alternating voltage of an industrial network. For this, rectifier diodes are used, combined in a common unit. Current filtering is carried out by high-capacity capacitors, which minimize the ripple of the incoming voltage. This is the answer to the question why you need a frequency converter.

In some cases, a so-called energy drain circuit, consisting of a transistor and a high power dissipation resistor, can be included in the circuit. This circuit is used in braking mode to cancel the voltage generated by the motor. Thus, the overcharging of the capacitors and their premature failure are prevented. As a result of the use of chastotniks, asynchronous motors successfully replace DC electric drives, which have serious drawbacks. Although easy to adjust, they are considered unreliable and expensive to operate. During operation, brushes constantly spark, and electroerosion leads to wear of the collector. DC motors are completely unsuitable for explosive and dusty environments.

Unlike them, asynchronous motors are much simpler in design and more reliable due to the absence of moving contacts. They are more compact and cheaper to operate. The main disadvantage is the complex adjustment of the rotation speed by traditional methods. To do this, it was necessary to change the supply voltage and introduce additional resistances into the winding circuit. In addition, other methods were used, which in practice turned out to be uneconomical and did not provide high-quality speed control. But, after a frequency converter for an asynchronous motor appeared, which allows you to smoothly adjust the speed over a wide range, all problems were resolved.

Simultaneously with the frequency, the input voltage also changes, which makes it possible to increase the power factor of the electric motor. All this makes it possible to obtain high energy performance of asynchronous motors and extend their service life.

The principle of operation of the frequency converter

Effective and high-quality control of asynchronous electric motors has become possible through the use of frequency converters in conjunction with them. The overall design is a frequency-controlled drive, which has significantly improved the technical characteristics of machines and mechanisms.

A frequency converter acts as a control element of this system, the main function of which is to change the frequency of the supply voltage. Its design is made in the form of a static electronic unit, and the formation of an alternating voltage with a given variable frequency is carried out at the output terminals. Thus, by changing the amplitude of the voltage and frequency, the speed of rotation of the electric motor is regulated.

Asynchronous motors are controlled in two ways:

• Scalar control operates in accordance with a linear law, according to which the amplitude and frequency are proportional to each other. The changing frequency results in changes in the amplitude of the incoming voltage, affecting the torque level, efficiency and power factor of the unit. The dependence of the output frequency and supply voltage on the load torque on the motor shaft should be taken into account. In order for the load torque to be always uniform, the ratio of the voltage amplitude to the output frequency must be constant. This balance is just maintained by the frequency converter.
• Vector control keeps the load torque constant over the entire frequency range. The control accuracy increases, the electric drive responds more flexibly to changing output loads. As a result, the motor torque is directly controlled by the inverter. It should be borne in mind that the torque is formed depending on the stator current, or rather, on the magnetic field created by it. Under vector control, the phase of the stator current changes. This phase is the one that directly controls the torque.

Adjusting the frequency converter for the electric motor

In order for the frequency converter for an asynchronous motor to fully perform its functions, it must be correctly connected and configured. At the very beginning of the connection to the network, a circuit breaker is placed in front of the device. Its rating must match the amount of current consumed by the motor. If it is supposed to operate in a three-phase network, then the machine must also be three-phase, with a common lever. In this case, in case of a short circuit in one of the phases, other phases can be quickly disconnected.

The operating current must have characteristics that fully correspond to the current of a single phase of the electric motor. If the frequency converter is planned to be used in a single-phase network, in this case it is recommended to use a single machine, the rating of which should be three times the current of one phase. Regardless of the number of phases, when installing a chastotnik, the machines should not be included in the break of the ground or neutral wire. It is recommended to use only direct connection.

With the correct setting and connection of the frequency converter, its phase wires must be connected to the corresponding contacts of the electric motor. Pre-winding in the motor, depending on the voltage supplied by the converter. If it is the same as the smaller value printed on the motor housing, delta connection is applied. A higher value uses the star schema.

Next, the frequency converter is connected to the controller and the control panel, which is included in the delivery. All connections are made in accordance with the diagram given in the instruction manual. The handle must be in the neutral position, after which the machine turns on. Normal activation is confirmed by a light indicator on the remote control. In order for the converter to work, the RUN button, programmed by default, is pressed.

After a slight turn of the handle, the motor starts to rotate gradually. To switch the rotation in the opposite direction, there is a special reverse button. Then, using the handle, the desired speed is adjusted. On some consoles, instead of the speed of the electric motor, data on the frequency of the voltage is displayed. Therefore, it is recommended to carefully study the interface of the installed equipment in advance.

Frequency converters for asynchronous motors

Thanks to frequency converters, the operation of modern asynchronous motors is highly efficient, stable and safe. This is especially important, since each electric motor has its own individual characteristics of the mode of operation. Therefore, optimization of the power supply parameters of units using frequency converters is of great importance. When a frequency converter is selected for any specific purpose, its operating parameters must be taken into account in this case.

The normal operation of the device will depend on the type of electric motor, its power, range, speed and accuracy of adjustments, as well as maintaining a stable shaft torque. These indicators are of paramount importance and should be organically combined with the dimensions and shape of the apparatus. You should pay special attention to how the controls are located and whether it will be convenient to use them.

When choosing a device, you need to know in advance in what conditions it will be used. If the network is single-phase, then the converter must be the same. The same applies to three-phase devices. Much depends on the power of asynchronous motors. If a high starting torque is required on the shaft during start-up, then the frequency converter must also be designed for a higher current value.