When applied properly, the variable frequency drive (VFD) is the most effective motor controller in the industry today. Modern VFDs are affordable and reliable, have the flexibility of control, and offer significant electrical energy savings through greatly reduced electric bills.
They are used in a wide variety of applications for various reasons. For example, they are the most effective energy savers in pump and fan applications. They enhance process operations, particularly where flow control is involved. VFDs provide soft-start capabilities that decrease electrical stresses and line voltage sags associated with full voltage motor start-ups, especially when driving high-inertia loads.
Medium-Voltage Motors Ease Limits on Current Capacity and Power.
Most electric motors run on supply voltages under 600 V yet operating at these limits current-carrying capacity and output power needed for large industrial loads. Current limits pose an issue during motor start-up. Medium-voltage (MV) ac motors overcome such limits. MV motors work across a range of industries from utilities and raw materials processing to pulp and paper production. User plants tend to be large and sited far from the power source. Applications center on driving large compressors, conveyors, crushers, fans, pumps, and related machines at fixed or variable speeds.