What are variable frequency drives? What are AC motors?
Variable frequency drives (VFDs), or ac drives, are designed to reduce energy usage by controlling the speed of the motor and can offer cost-effective benefits for plants. AC motors convert electrical energy into mechanical rotating or linear energy to operate industrial equipment.
Permanent magnet synchronous motors offer significant advantages on high-energy-consuming and high-dynamic applications, compared to induction motors. See table, photo gallery.
The types of ac drives used with ac induction motors are V/Hz, encoderless and flux vector. While there are many drives available for synchronous and servo motors, induction motors have the majority of applications. Sensorless vector control is the same as encoderless vector control, which better describes its operation.
Powerful analytical tools — software, PCs, networks, and the internet — are within a click of the mouse. Power monitoring equipment captures data; software analyzes critical data required for responsible electrical energy management. Power management software tools provide control over how you manage your use of electricity.
The August 14, 2003 blackout emphasized that power quality should not be taken lightly. The blackout was caused by, and affected the power grid — our nation's electrical infrastructure. The issues raised by this event should and will come under scrutiny. Just as the nation looks at its power quality issues, plant engineers must look at power quality issues inside the plant.
Key Concepts NEMA and IEC motor controls differ in size, ruggedness, and complexity. The solid-state overload relay is common to both NEMA and IEC motor controls.