The acronym VFD stands for Variable Frequency Drive. The other names of VFD include inverters and AC drives. VFD can be used to make the AC motor work and run at different or variable speeds. A motor which is devoid of VFD will run at a speed that depends (and is directly proportional to) the voltage applied to it. For instance, an AC motor rated for 50 Hz will run faster if it gets a higher voltage from the main supply and slower when the voltage is low. The power surges and inconsistency increase energy expenditure and also damage the components of the motor. The electronic controller VFD can change the frequency that is being supplied to the induction motor and bring in more consistency.
While the VFDs of the 1960s had smaller components, the availability of large transistors, later on, made it possible to control the speed of even the largest of motors. A variable frequency drive nowadays can be used to control the amount of electricity that goes inside any motor, irrespective of its size. Here are the 5 major benefits of a VFD.
Energy and Cost Savings
When the motor is aided and controlled by the VFD, excessive electricity is not drawn during the initial startup/acceleration of the motor. The drive provides for saving of electricity, energy, and costs. A VFD fully covers its cost within one year of installation.
Traditional motor starters draw the Locked Rotor Amperage (LRA) during initial start-up. When there are many motors in a manufacturing plant, the combined LRA increases the demand for electricity manifold. Industries using this traditional approach end up paying penalties that are levied on to them because of electric excessive electricity usage. The penalty fee may be as much as 25% of the energy bill value. Therefore, industries stand to gain a lot and reduce undesired expenditures by using VFDs for all motors.
The modern VFDs are microprocessor based. They are highly versatile and can control the speed of the motor while protecting the components against the overcurrent ramp-down and ramp-up motor conditions. VFD can be used for braking, possess a variety of controls for the ramp down circumstances, and also provide the much-desired boost up during the ramp-up condition.
In the absence of a VFD, there will be a huge jolt during motor start-up, because the force of electricity will be sent to the motor and this in-flow of current will not be regulated. With the use of VFD, the release of power is much more controlled and smooth. A motor gets ample time to ramp up, thereby preventing wear and tear. Not only the acceleration, but the declaration is also smooth, which adds to the longevity of VFD controlled motors.
A variable frequency drive also protects the motor against the power surges and the over/under current scenarios. It reduces the wear and tear of the components of the motor to a great extent, which contributes to the much greater lifespan of the original motor.
The market for VFD is increasing rapidly and will be more than 24 billion by the year 2021. They are necessary to comply with the regulations and avoid penalties. The new drives optimize the operational flows while reducing downtime.