FACTORS INFLUENCING THE CHOICE OF ELECTRICAL DRIVES
· Nature of electric supply
o Whether AC or DC supply is to be used for supply
· Nature of the drive
o Whether the particular motor is going to drive individual machine or a group of machines
(iii)Capital and running cost
· Maintenance requirement
· Space ad weight restrictions
· Environment and location
· Nature of load
§ Whether the load requires light or heavy starting torque
§ Whether load torque increases with speed remain constant
§ Whether the load has heavy inertia which may require longer straight time
· Electrical characteristics of motor
§ Starting characteristics,
§ running characteristics,
§ speed control and
§ Braking characteristics
· Size, rating and duty cycle of motors
§ Whether the motor is going to the operator for a short time or whether it has to run continuously intermittently or on a variable load cycle
o Mechanical considerations
§ Type of enclosures, type of bearings, transmission of drive and Noise level.
§ Due to practical difficulties, it may not possible to satisfy all the above considerations.
§ In such circumstances, it is the experience and knowledge background which plays a vital role in the selection of the suitable drive.
The following points must be given utmost important for the selection of motor.
The factors are:
t Nature of the mechanical load driven
t Matching of the speed torque characteristics of the motor with that of the load
t Starting conditions of the load.