Today the VFD is perhaps the most common kind of result or load for a control system. As applications are more complex the VFD has the capacity to control the quickness of the engine, the direction the electric motor shaft is turning, the torque the electric motor provides to a load and any other motor parameter which can be sensed. These VFDs are also available in smaller sized sizes that are cost-efficient and take up less space.
The arrival of advanced microprocessors has allowed the VFD works as an extremely versatile device that not merely controls the speed of the electric motor, but protects against overcurrent during ramp-up and ramp-down conditions. Newer VFDs provide ways of braking, power boost during ramp-up, and a variety of regulates during ramp-down. The largest cost savings that the VFD provides can be that it can ensure that the engine doesn’t pull extreme current when it begins, therefore the overall demand element for the whole factory can be controlled to keep the domestic bill as low as possible. This feature alone can provide payback more than the price of the VFD in under one year after purchase. It is important to keep in mind that with a traditional motor starter, they’ll draw locked-rotor amperage (LRA) if they are beginning. When the locked-rotor amperage occurs across many motors in a manufacturing facility, it pushes the electrical demand too high which frequently results in the plant paying a penalty for all of the electricity consumed during the billing period. Because the penalty may end up being as much as 15% to 25%, the savings on a $30,000/month electric bill can be utilized to justify the buy VFDs for virtually every motor in the plant also if the application form may not require operating at variable speed.
This usually limited the size of the motor that could be managed by a frequency and they were not commonly used. The earliest VFDs utilized linear amplifiers to regulate all aspects of the VFD. Jumpers and dip switches were utilized provide ramp-up (acceleration) and ramp-down (deceleration) features by switching larger or smaller sized resistors into circuits with capacitors to make different slopes.
Are you curious about Variable Speed Gear Motor?