How to choose a frequency converter for your company

Many modern electronic asynchronous motors require not only shaft speed but also torque to be changed. To meet this need, special devices called frequency converters are used. Their most common application is in automatic control systems, including commercial and industrial systems such as compressor units, fans, conveyors, and similar equipment.

The frequency converter operates according to the following algorithm: a changed frequency and voltage are supplied to the motor, which makes it possible to control torque and speed. It all depends on what requirements are dictated by the production process.

There are many factors to consider for a converter to work properly, including:

1. Engine power.
2. Type of power unit.
3. Rated frequency and voltage.

Finally, the frequency converter itself must be set up correctly, according to the manufacturer’s instructions.

Assessment of enterprise needs

The choice of this or that equipment is 100% determined by the needs of the enterprise. A similar situation exists with frequency converters, so it is worth determining what tasks this equipment will perform, with what intensity and efficiency.

In general, frequency converters can reduce the cost of electricity and engine maintenance. It also increases the efficiency of the power plant.

For example, lifting equipment and cranes are equipped with frequency converters, because you always need to change the speed of the electric motors and the direction of the shaft (lifting or lowering the load). Do not forget that the beginning and end of the movement of the installation should be smooth, without jerks. Therefore, for a particular type of crane or lifting mechanism, it is necessary to accurately calculate the type of frequency converter that will work in conjunction with the electric motor.

In order to automatically control the force of air injection or exhaust by means of fans, frequency converters must also be installed. If you need to increase the thrust, the motor speed increases by controlling it via the frequency converter.

Before installing conveyors and conveyor belts, the speed of cargo movement is calculated. The task becomes as simple as possible when using the above-mentioned equipment. The situation is the same with miscalculations of the operating modes of pumping units, production machines, etc.

Motor type and compatibility

Today, frequency converter control is possible on almost any motor. However, in each case, a different type of frequency converter is chosen:

1. Induction or asynchronous motors with a rotor with a short-circuited winding.
2. Asynchronous motors with external rotor.
3. Synchronous motors.

The most common combination is a frequency converter tandem with an asynchronous single-phase motor equipped with a 220 V squirrel-cage rotor. To control such a power unit, frequency converters with a capacity of 0.75 to 3.7 kW are installed.

The 220 V asynchronous three-phase motor (phases are connected in a delta pattern) is controlled in scalar and vector mode. For example, this can be provided by several frequency inverters, including Hiconics’ HIVERT-Y/T series of common medium voltage, HIVERT-Y/T water-cooled, and others.

Converter power and performance

Typically, a frequency converter is selected based on many parameters, but one of the most important is power and performance. There is a rule that the power of the frequency converter must be higher than the power of the motor being controlled. For example, if the motor has a rated power of 2.5 kilowatts, then the converter is set to 3 kW.

To maximize the performance of the frequency converter and the motor-frequency converter pair in general, the converter should be installed at the maximum motor current. Be sure to take into account the overload capability of the frequency converter. If you need to use a motor with a significant starting torque, it is recommended to install an even more powerful converter.

But if you need to equip braking systems based on synchronous motors, the rated current of the converter itself will be a priority: its rating is selected higher than the motor current rating.

Energy efficiency and resource saving

The main advantage of frequency converters is that they can significantly save energy costs when operating any motor. Another advantage related to the energy efficiency of a frequency converter is the ability to precisely control production processes, while reducing wear and tear on engine components and other moving parts.

Regardless of the industry in which a particular frequency converter is used, it helps to extend the service life of motors by reducing the load during certain operating hours and reducing the shaft speed to the parameters required by the specific operating mode.

How to choose the right frequency for your needs

Every company that strives for energy efficiency and increased productivity should choose a frequency converter that optimizes its technological processes.

There is a lot of equipment on the market, models that differ in power, settings, functionality, etc. Taking these circumstances into account, you can eliminate mistakes when choosing a frequency converter, as well as create the safest, most efficient conditions at work.

The first parameter when choosing a device is power. Here you should pay attention to the total power of the equipment on which the electric motor is installed. Consider not only the rated performance, but also the ability of the power unit to operate at peak loads.

Next, you should pay attention to the functionality of frequency converters, such as automatic motor overload protection, speed control, and the ability to integrate with additional automation systems.

Finally, the purchased frequency converter must be compatible with previously installed control systems. The lower the cost of modernizing the equipment, the better.

What to ask the supplier when choosing

In addition to the parameters that should be considered when choosing a frequency converter, there are other indicators. They can be requested from the equipment supplier when placing an order.

Yes, the supplier must specify the permissible type of installation of the frequency inverter. Preference is given to units that meet the various requirements of the installation site. The vast majority of models have a degree of protection according to the IP20 classification, i.e. the equipment should be installed in an electrical cabinet, paired with forced ventilation (preferably). More expensive frequency converters have an IP65 index, which means they can be installed in an open area.

Proven companies that sell frequency converters for various industries on the market always have technical support and after-sales service. This is exactly what you can count on when ordering from our company Dalgakiran.