The Energy Saving Role of Frequency Inverters
A frequency inverter is a type of adjustable speed drive that’s commonly used in electro-mechanical drive systems used to control torque and AC motor speed by varying motor input voltage and frequency. Frequency inverters are used in applications ranging from large mill drives and compressors to the smallest of appliances.
Around 25% of the world’s electrical energy is used by electric motors in industrial applications. These are specifically conducive for energy savings using frequency inverters in centrifugal load services. The inverters’ global market penetration for all applications is still quite small and this lack of penetration emphasizes significant efficiency improvement opportunities for new inverter installations.
Over the past few years, due to technological advancements, the prices of frequency inverters have dropped and their performance has been improved thanks to the advances in drive topologies, semiconductor switching devices, control and simulation techniques as well as control software and hardware.
Most fixed-speed motor applications which are supplied directly from an AC line power could save energy when operated at variable speeds imposed by a frequency inverter. Such energy cost savings are specifically pronounced in variable-torque pump and fan applications, where the load’s power and torque vary in the cube and square of the speed.
The AC motors used in inverters are usually three-phase induction motors. Some single-phase type motors can also be used but three-phase motors are the preferred type. Different types of synchronous motors offer more advantages in certain situations, but the three-phase induction are suitable for almost all purposes and are usually the most economical choice. Motors designed for fixed-speed operation are also used quite often.
AC drives are used to bring quality and process improvements in the commercial and industrial applications’ flow, acceleration, pressure, temperature, speed, monitoring, torque and tension. Fixed-speed loads subject the motor to current surges 8 times the full-load current and high starting torque. AC drives on the other hand, gradually ramp it up to operating speed to lessen electrical and mechanical stress, reduce repair and maintenance costs and extend the life of the driven equipment and the motor.
Modern inverters have never been safer than they are nowadays, plus they come with extra features to increase safety. However, as a means of precaution and avoiding accidents, it’s always advisable to read the instructions before using the device. In case of a blackout, treat it just like a generator, and if you’re supplying its power through your car, you’ll need extra fuel stored in a cool and ventilated area, away from any heat or sparks.