Today the VFD could very well be the most common kind of result or load 
for a control program. As applications become more complicated the VFD has the capacity to control the acceleration of the electric motor, the direction the electric motor shaft is definitely turning, the torque the electric motor provides to a load and any other electric motor parameter which can be sensed. These VFDs are also available in smaller sizes that are price-efficient and take up less space.
The arrival of advanced microprocessors has allowed the VFD works as an exceptionally versatile device that not merely controls the speed of the motor, but protects against overcurrent during ramp-up and ramp-down conditions. Newer VFDs provide ways of braking, power enhance during ramp-up, and a variety of settings during ramp-down. The largest financial savings that the VFD provides is certainly that it can make sure that the electric motor doesn’t pull excessive current when it begins, so the overall demand factor for the whole factory can be managed to keep the utility bill only possible. This feature by itself can provide payback in excess of the price of the VFD in under one year after buy. It is essential to remember that with a traditional motor starter, they will draw locked-rotor amperage (LRA) when they are beginning. When the locked-rotor amperage happens across many motors in a manufacturing facility, it pushes the electric demand as well high which often results in the plant having to pay a penalty for every one of the electricity consumed through the billing period. Since the penalty may be just as much as 15% to 25%, the savings on a $30,000/month electric expenses can be used to justify the purchase VFDs for virtually every electric motor in the plant even if the application may not require working at variable speed.
This usually limited the size of the motor that could be managed by a frequency and they weren’t commonly used. The earliest VFDs utilized linear amplifiers to control all areas of the VFD. Jumpers and dip switches were used provide ramp-up (acceleration) and ramp-down (deceleration) features by switching larger or smaller resistors into circuits with capacitors to generate different slopes.
No other company has been able to compete with our new Variable Speed Gear Motor.