Variable Speed Drive

Company Description

Variable Speed Drives (http://www.vsdrive.com ) Induce Shaft Currents in AC Motors. Due in large part to an increased focus on energy savings, the use of pulse-width-modulated (PWM) variable speed drives to control AC motors has grown dramatically over the last few years. While they offer low operating costs and high performance, variable speed drives are not without their problems. Shaft currents induced by variable speed drives can lead to motor failures. Without some form of mitigation, shaft currents travel to ground through bearings, causing pitting, fusion craters, fluting, excessive bearing noise, eventual bearing failure, and subsequent motor failure.

Types of Variable Speed Drives
Mechanical Variable Speed Drives
Variable pitch drives
Traction drives
Hydraulic Variable Speed Drives
Hydrostatic drives
Hydrodynamic drives
Hydroviscous drives
Continuously Variable Transmission (CVT)
Electric Variable speed drives
DC motor drives
Eddy current drives
AC motor drives
Slip controlled drives

Why Use variable frequency drives
Saving energy
Process control
Smoother operation
Acceleration/deceleration control
Different operating speed for each process mode
Compensate for changing process variables
Allow slow operation for setup purposes
Adjust rate of process parameters
Allow accurate positioning
Control torque or tension
Assumes the need for Variable speed
Variable output
Steady state condition
Reduced capital expenditure
Solid state electronic poVariable Speed Driver conversion devices
Reduced maintenance