Frequency converters are essential devices in electrical systems that provide speed control and energy savings. By changing the speed of asynchronous (induction) motors, frequency converters significantly reduce operating costs. Frequency converters are almost indispensable in modern industrial applications. This website brings together frequency converters and related power electronics products for businesses and engineers.
Frequency converters, also known as VFDs (Variable Frequency Drives) or inverters, convert fixed-speed motor control into variable-speed control. Frequency converters allow the motor to adjust its operating speed according to the work requirements.
Frequency converters convert mains AC electricity to direct current (DC) and then back to AC electricity. By changing the frequency and voltage of the output AC electricity, the frequency converter controls the motor speed. Frequency converters can automatically adjust the speed according to the motor load.
Frequency Converter Working Principle
A frequency converter operates through a three-stage process. In the first stage, the frequency converter converts mains AC electricity to direct current (DC). In the second stage, the frequency converter stores and stabilizes the DC electricity on the DC line. In the third stage, the frequency converter converts the DC electricity back into AC electricity with variable frequency and voltage.
The frequency converter can immediately provide output in an approximate frequency range of 0-120 Hz. The frequency converter operates according to the formula: Motor speed = 120 × Frequency / Number of poles. The frequency converter provides continuous speed control without changing the motor’s torque.
Types of Frequency Converters
Frequency converters are manufactured with different specifications and power ratings. Single-phase frequency converters are suitable for low-power applications (1-5 kW). Three-phase frequency converters are suitable for medium and high-power applications (5-500+ kW).
Welding type frequency converters are of the traditional type and have a transformer-based design. Non-welding frequency converters have a more modern and compact design. Modular frequency converters can be connected in parallel to increase capacity.
Frequency Converter Energy Saving
The most important advantage of a frequency converter is its energy saving capability. By adjusting the motor speed according to the load, the frequency converter prevents unnecessary energy consumption. According to affinity laws, power = speed³, a small reduction in speed results in significant power savings.
For example, reducing the motor speed by 80% reduces power consumption by 51%. A frequency converter can reduce energy costs by 30-50% within a year. Frequency converters are very beneficial in terms of environmental protection and operating cost savings.
Frequency Converter Applications
Frequency converters are highly efficient in variable load applications such as water pumps and air compressors. They are useful for industrial fan and ventilation systems. Frequency converters are used for speed control of conveyor belts.
Frequency converters are indispensable in extrusion and paper production machines. They are necessary for controlling lathe systems in old and elevator systems. In practical applications, frequency converters improve air quality and save energy in water systems.
Frequency Converter and Motor Compatibility
Frequency converters are compatible with most AC induction motors. However, it is important to check the motor design when selecting a frequency converter. The frequency converter output can create additional stress on the motor insulation.
Frequency converters may have issues with some older design motors. For frequency converter use, the motor design category (e.g., IE3 or higher) should be checked. Newer motors are fully compatible with frequency converters and are more efficient.
Frequency Converter Selection
When selecting a frequency converter, it is necessary to determine the motor power (kW) and nominal speed (RPM). The frequency converter should be selected to be equal to or slightly more powerful than the motor power. The frequency converter can have air cooling or liquid cooling options.
The frequency converter should control whether the input is 1-phase or 3-phase. Output cabling and protection (circuit breaker) planning should be done for the frequency converter. The frequency converter must be compatible with the electrical infrastructure.
Frequency Converter Installation and Configuration
Frequency converter installation is the responsibility of electrical engineers. The frequency converter must be connected under proper circuit breaker protection. Screen filtering may be required depending on the motor and power source.
Frequency converter configuration is done using specialized software. Frequency converter parameters must be adjusted according to motor type, power, and application. Starting ramps and stopping modes can be configured on the frequency converter.
Frequency Converter Maintenance and Troubleshooting
Frequency converters require regular maintenance. The air filters must be kept clean. The ventilation opening must not be blocked, and the frequency converter must be protected against overheating.
The electrolytic capacitors in the frequency converter can deteriorate over time. Reading and analyzing error codes is important. If a frequency converter malfunctions, an electrician should be contacted.