Electrical Engineering is making itself more advanced day-by-day and to achieve that Electric Drives play a very vital role. Drives mean a system employed for controlling motion. Today’s era is the developing era in which everything is changing and getting advanced with the technology and these Electric Drives are one among many such innovations.
THE TECHNOLOGY BEHIND ELECTRIC DRIVES
Motors which are used in electric drives are shunt and series dc motor, induction synchronous, whereas in some special cases we can use brushless dc motor, reluctance motor, servo motor and stepper motor.
Electric drives have following parts, which are: motor, power modulator (it can be a rectifier, amplifier or converter, etc) control unit, source and load. There are large numbers of loads and each load has its own specific requirements. Mostly, it is a closed loop feedback system whereas the factors which govern choice of electric drives include investment cost, operating cost, maintenance cost, speed- torque characteristics, space requirement, starting, braking requirement, etc. And unlike other prime movers, in electric drives there is no need to refuel or warm-up the motor. They can be started instantly and can be fully loaded immediately.
ADVANTAGES:
We have number of advantages of using electric drives, some of them are:
(a) Energy saving
(b) Process control technique has been improved
(c) It gives high power factor
(d) It provide soft start and mechanical stress is reduced
(e) It doesn’t pollute the environment
(f) It can be operated in all the four quadrants of speed-torque plane.
APPLICATIONS:
Earlier methods of speed control of electric motors are not very efficient. Advent of power electronic devices has resulted in numerous methods of speed control of electric motors. In servo applications, the control must be very precise, accurate and should have minimum response time. Speed or position feedback is used in many servo applications to ensure accuracy and precision.
Electric motor drives are used in a very wide range of sizes from a few watts to thousand of kilowatts. A very small size motors are used in toys and households applications like fans, washing machines, etc whereas very large size motors are used in electric traction and many heavy industries.
Many industries require electric motors whose speed can be adjusted as per requirement and this is done through Variable Speed Electric Drives. Variable Speed Drives constitute an integral part of automation. In many industries, a reversal in direction of rotation is also required additional to variation of speed.
These all applications prove electric drives to be a boon in the Electrical world.
