Six primary benefits of VFDs are:
1. Keeps starting current in control: A VFD has the capability of starting the motor at zero voltage and frequency, which keeps a check on motor winding flexing and heat generation. This helps in extending the motor life.
2. Reduces power line disturbances: Any voltage sag caused in the power line can adversely affect voltage sensitive devices such as proximity switches, sensors, and computers. Using VFDs eliminates voltage sag.
3. Demands lower power on start: Power required to start an ac motor across the line is substantially greater than with a VFD. When industrial customers start these motors during peak hours of electrical consumption, they are likely to be charged with surge prices. However, with VFD demanding lower starting power, the issue can be addressed.
4. Helps in controlling operating speed and acceleration: Applications such as bottling lines that include easy-to-tip product significantly
benefit from a gradual increase in power. This allows conveyer belts to smoothly rev up rather than an abrupt jerk to full power. They also allow speed to be remotely adjusted by a controller. Control is speed and acceleration is a big bonus to industries in a production process.
5. Limits and adjusts torque: The drive is capable of limiting and adjusting the amount of torque so the ac motor never surpasses this limit. This protects machinery from damage and protects the process or product.
6. Saves energy and cost: A VFD regulating a pump motor that usually runs less than full speed can cut down energy consumption over a motor running at constant speed for the same period. In addition, it eliminates the need for mechanical drive components, which also helps reduce overall costs.
Source: <https://www.controleng.com/articles/vfds-six-benefits-energy-efficiency/>