Benefits of Variable Frequency Drives (VFDs, AC Drives)
Variable speed drives (VSDs) are used for two primary reasons:
1. To improve the efficiency of motor-driven equipment by matching speed to changing load requirements (energy saving).
2. To allow accurate and continuous process control over a wide range of speeds (Better process control).
Motor-driven centrifugal pumps, fans and blowers offer the most dramatic energy-saving opportunities.
In some applications, such as conveyers, machine tools, and other production-line equipment, the benefits of accurate speed control are the primary consideration of using VFDs. VFDs can increase productivity, improve product quality and process control, and reduce maintenance and downtime.
In addition to two main benefits (energy savings and better process control), Variable Frequency Drives (VFDs) can provide other benefits:
1. VFDs may be used for control of process temperature, pressure or flow, without the use of a separate controller. Suitable sensors and electronics are used to interface the driven equipment with the VFDs.
2. Maintenance costs can be lower, since lower operating speeds result in longer life for bearings & motors.
3. Eliminating the throttling valves and dampers also does away with maintaining these devices and all associated controls.
4. With a VFD (VSD, AC Drive), A soft starter for the motor is no longer required.
5. Controlled ramp-up speed in a liquid system can eliminate water hammer problems.
6. The ability of a Variable Frequency Drive (VFD) to limit torque to a user-selected level can protect driven equipment that cannot tolerate excessive torque.
