If you are running any kind of operation which involves electric motors large or small, it is likely you have already heard of the mysterious variable frequency drive. If you haven’t, it is high time you get informed because this invention can cut energy costs, increase production control and efficiency, and reduce equipment wear and tear. Read on for the full details.
The variable frequency drive, also known as an adjustable frequency or variable speed drive, is a special component of electro-mechanical drive systems which controls alternating-current motor speed and torque. It achieves this effect by varying motor input frequency and voltage. It is a component in electric motor systems which typically consist of an AC motor, a main drive controller assembly, and a drive-operator interface for adjusting the voltages and manual controlling.
Nowadays, up to 25 per cent of the total electricity consumption in the world is generated by electrical motors. Given that fact, it is astounding that variable frequency drives are far from widespread. Many fixed-speed electrical motors with an AC power supply can realise considerable energy economies if supplied with a variable speed drive. For example, a motor operating at 63 per cent its former fixed speed will use only about a quarter of its full-speed energy. This produces significant savings at a negligible speed reduction.
Variable speed drives allow for much closer control of motor performance and, thus, improve the quality of operation and help maintain equipment. Fixed-speed motors habitually take high starting torque and experience current surges up to eight times the standard load upon starting. A system supplied with a variable frequency drive, on the other hand, will gradually rev up to the desired speed without the initial shocks. With the reduced stress, both mechanical and electrical, the life and wellbeing of equipment are prolonged. Another useful feature of variable frequency drives is that they facilitate running specific patterns on the motor, which can further help reduce shocks to the system and other undesirable effects. Acceleration and deceleration control are one prominent area where variable speed drives find extensive use.
Even if your equipment came with a fixed-speed motor, this is not a problem. If you determine you will benefit from the upgrade, you can retrofit a variable frequency drive easily.