Variable Frequency Drives

Variable Frequency Drives

A VFD (Variable Frequency Drive) can be defined as a motor controller. This controller’s main responsibility is to drive the electric motor. This is done through variations in the frequency and voltage, which are provided to the motor as input. This device is known by many names including variable and/or adjustable speed and/or frequency drives, AC drive, micro-drive and inverter.

The frequency and the motor’s speed have a directly proportional relationship, which means that if the frequency is fast, the RPM (speed) will also be fast accordingly. If the motor is required and used in an application which does not demand maximum speed from the motor then the VFD can be used so that both the voltage and frequency are lowered. This ensures that no damage is caused by failing to meet the requirements. However, the working of the VFD is not limited to this. It can alter the speed any way (up or down) as is required by the application even if it keeps changing.
There are various benefits of using a VFD.

If the application in question does not require maximum speed then the VFD is able to lower the energy costs by controlling the motor. This means that the energy consumption is reduced significantly. This feature is unique to the VFD as no other process can ensure this cost effectiveness. An estimated 70% of energy consumption can be reduced if the installed or upgraded systems make use of the functionalities of VFDs. It undoubtedly lowers the production cost while also enhancing the quality of the product.

Usage of VFDs also helps in terms of revenue generation. This is due to the fact that the motors will be operated efficiently and also as error count will be low while levels of production will be high. The whole benefit includes tighter process control.

The equipment will also have a longer life expectancy while having lesser downtime in maintenance. As the VFDs ensure maximum control of the motor, this results in more appropriate protection from over-loads, under-loads, phase protection etc. The smooth start gets rid of belt, gear and bearing wear. Smooth accelerating and decelerating cycles also positively ensure that there is no or little need left for the water hammer.