Things You Should Know About Frequency Converters

We live in a world driven by appliances and circuits. A lot of our appliances use electrical components that are unknown to a common person who is not an engineer. One such component is the frequency converter which is a part of many circuits of ordinary appliances. Let us take a deeper look at the types of frequency converters and its

What is a Frequency Converter?

A frequency converter, known as a variable frequency drive or power frequency changer, is an electrical device component that converts the current of a specific frequency into a current with a different frequency. However, there is no change in voltage after the frequency change. A frequency converter is used to regulate the rotation speed of motors that operate pumps and fans. The input current usually has a frequency of 50-60Hz, whereas the output current is 400Hz. Let us illustrate the functioning of the frequency converter with an example of a fan that is supplied with a current of 400V at 50Hz. At this frequency, the fan has a specific spinning speed. If we want to increase the speed of the fan than a frequency converter, then we can utilize a frequency converter with an output frequency of 70Hz. If we desire the fan speed to be slower than a frequency converter which alters the frequency to 40Hz for

Frequency Converter Types

Rotary Frequency Converters

The process of converting input alternating current to rotational mechanical energy and then transmitting it to a generator for the production of electric alternating current output power is a common technique in the power generation industry. The electrical power output is usually measured in Kilowatts (kW) or Kilovolt-Amperes (KVA), while rotational power is expressed in Horsepower (HP). This technique requires the conversion of frequency, voltage, and/or phase as needed.

In motor-generator systems, the driving motor and generator can be coupled in various ways. Among these, rotary frequency converters are considered the best solution for motor loads. However, a typical industrial frequency converter manufacturer also offers belt-coupled converters as a simpler and more affordable option. They use drive belts and pulleys to transfer energy from the motor to the generator and can vary the frequency by altering the pulley ratio. Although some clients may express concern about the longevity of drive belts, when properly designed and installed, they rarely fail during operation.

For industrial uses, a 50Hz to 60Hz converter is excellent. These frequency converters can easily convert the frequency to a stable range of 50 to 60Hz. Rotary converters are built to operate in a wide variety of temperature conditions.

Solid State or Static Frequency Converter

Solid State frequency converters are devices used for converting incoming AC power into DC power (during the rectifier stage), followed by the conversion of the DC power into the desired AC frequency and voltage. These converters are particularly useful in situations where precision, size, noise levels, or adjustability are critical factors.

Static frequency converters, a type of solid-state frequency converter, have the advantage of being inherently quiet. As a result, they are particularly suitable for use in environments such as laboratories or offices, where noise levels must be kept to a minimum. One of the most common applications of static frequency converters is the conversion of single-phase to three-phase and three-phase to single-phase power. With their capacity for adjusting output frequency and voltage to specific needs, they are an excellent option for a wide range of industrial and scientific applications. One major application of solid-state converters is at airports, where it converts 50Hz to 400Hz as a ground power unit. Compared to rotary converters, static converters are temperature sensitive and cannot tolerate adverse humid conditions such as fog. They are housed in an airconditioned space to keep them at a constant temperature.

The downside of static converters is that, unlike rotary frequency converters, static converters are unsuitable for starting motors. Motors require a strong surge current or shock to move the motor from its resting position. Once the motor has started, the rotary converter switches to a normal operating current. A static current frequency converter is incapable of supplying this large but short current surge, and so turns off to protect itself.

Factors to Consider while Buying a Frequency Converter

A frequency converter is a device that can convert 60Hz to 50Hz and can also boost 110V to 220V via an internal step-up transformer or vice versa. However, before purchasing a frequency converter, it's important to determine the types of loads that the converter will be connected to. There are five common types of loads, which include resistive loads, inductive loads, capacitive loads, rectifier loads, regenerative loads, and mixed loads.

To ensure that the frequency converter is capable of handling the loads that it will be connected to, it's important to choose a converter with a power capacity that is suitable for the load capacities and types. This will help to ensure that the frequency converter functions effectively and provides the desired results.