To know the inverter drive is to know what the inverter drive does ? A variable frequency drive (VFD) is a motor controller that drives an electric motor by changing the frequency and voltage of its power supply. The VFD is also able to control the ramp up and ramp down of the motor during start or stop, respectively. Although the drive controls the frequency and voltage of the power supplied to the motor, we usually refer to it as speed control because the result is the adjustment of the motor speed.
There are many reasons why we might want to adjust the speed of this motor. For example, to conserve energy and improve system efficiency; convert power in hybrid applications; match drive speed to process requirements; match drive torque or power to process requirements; improve operating conditions; reduce noise levels, such as from fans and pump noise; reduce mechanical stress on the machine to extend its life; reduce peak consumption to avoid peak demand prices and reduce the size of the motor required. Additionally, today's drives integrate networking and diagnostics for better control of performance and increased productivity. Therefore, energy saving, intelligent motor control, and peak current reduction are three important reasons to choose a VFD as the controller in every motor drive system.
For what an inverter drive does, there are many different types of drives available today as they are widely used in industry. Both single-phase VFDs and three-phase VFDs have been developed to suit a variety of applications. Differences in drive types include methods for frequency and voltage control; and harmonic suppression techniques. The most common use of VFDs is to control fans, pumps and compressors, which account for 75% of all drives in operation worldwide. Soft starters and jumper contactors are other less complex types of motor controllers. A soft starter is a solid state device that slowly accelerates to full speed during motor startup. A jumper contactor is a motor controller that applies full line voltage to the motor.
What does an inverter drive do? A variable frequency drive can use VFD control to vary the power supplied to match the energy demand of the driven equipment, which is how it saves energy or optimizes energy consumption. The drive can significantly reduce energy consumption compared to direct-on-line (DOL) operation, where the motor runs at full speed regardless of demand. Using a drive, it is common to save 40% in electricity or fuel. The rolling effect means that using a drive can also reduce the NOx emissions and CO2 footprint of the system in which it is installed.