An electronic drive that controls AC motor speed by varying the frequency and voltage of the power supply to the traction motor.
Full Definition
Also called a variable frequency drive (VFD) or inverter drive, a frequency inverter converts fixed-frequency mains power to a variable-frequency AC output, allowing smooth acceleration and deceleration of the elevator motor. This eliminates the mechanical shock of direct-on-line starting, reduces energy consumption during partial-load operation, and extends motor and rope lifespan. Modern frequency inverters incorporate regenerative capability, feeding braking energy back to the building grid.
