For those of you who do not know what a frequency converter is, it is an electronic device that can convert alternating current from one frequency to another frequency. There has always been the same need to convert main voltage and frequency into quantities, but it wasn’t always done the same. This led to many improvements in modern frequency converters technology. The first type of FC’s has thyristors and analogue technology whereas the FC’s of today feature microprocessor controls and digital units making them far more advanced than the first few models. These developments come because of the automation industry. This industry is always looking for more automated control and better production speeds so it is forever changing and looking for ways to improve.
The next thing we will touch on, is the speed control of electric motors. There are so many different terminologies used to alter the speed of electric motors. Some of the most common terms used include frequency converters, variable frequency drive, variable speed drive, adjustable frequency drive, and adjustable speed drive. While some of these terminologies refer to speed control in general like variable speed drive and adjustable speed drive, some are more specifically referring to the adjustment of the feeding frequency of a motor like the adjustable frequency drive or variable frequency drive. We will continue to use the term frequency converter as is it covers the electronic parts of the device and all of the components like the current sensor and interface.
So why use speed control in the first place? There are many reasons why this is such a popular application, some of which include:
- the saving of energy
- more efficient systems
- you can easily match the speed of the drive and process requirements
- lower noise levels on certain equipment
- reduce mechanical stress on machines
- improve the workplace environment
- you can also easily match the torque and power to the process requirements.
Now some benefits may work better than others depending on the application, but they have been proven time and time again.
The newer frequency converters can be used to maintain speed or torque of a machine with great accuracy. Now people who manufacture motors employ many different techniques to get high efficiency out of electric motors. For those who do not understand completely, it can be difficult to see the difference between them but we all know that energy efficient motors need high technology controls. When you break it down, all motors are operated by different control algorithms which are made for each motor. A frequency converter is designed for a group of motor technologies but has all the different algorithms built in by the manufacturer.
There are many benefits so there should be not reason to ask why frequency converter are used, if you have technologies that run at high power but do not need that much, it can easily burn out the equipment and shorten its lifespan dramatically. A frequency drive can adjust this so that it is only getting the amount of power that it needs. If you are someone who has problems with voltage dropping, torque, or currents during the start up, investing in a frequency converter will solve most of these issues.