Advantages of Electrical Drive
They have flexible control characteristics. The steady state and dynamic characteristics of electric drives
can be shaped to satisfy the load requirements.
1. Drives can be provided with automatic fault detection systems. Programmable logic controller
and computers can be employed to automatically control the drive operations in a desired
2. They are available in wide range of torque, speed and power.
3. They are adaptable to almost any operating conditions such as explosive and radioactive
4. It can operate in all the four quadrants of speed-torque plane
5. They can be started instantly and can immediately be fully loaded
6. Control gear requirement for speed control, starting and braking is usually simple and easy to
Choice (or) Selection of Electrical Drives
Choice of an electric drive depends on a number of factors. Some of the important factors are.
Steady State Operating conditions requirements:
Nature of speed torque characteristics, speed regulation, speed range, efficiency, duty cycle,
quadrants of operation, speed fluctuations if any, ratings etc
Transient operation requirements:
Values of acceleration and deceleration, starting, braking and reversing performance
Requirements related to the source:
Types of source and its capacity, magnitude of voltage, voltage fluctuations, power factor,
harmonics and their effect on other loads, ability to accept regenerative power
Capital and running cost, maintenance needs life.
Space and weight restriction if any.
Environment and location.
Group Electric Drive
This drive consists of a single motor, which drives one or more line shafts supported on
bearings. The line shaft may be fitted with either pulleys and belts or gears, by means of which a group of
machines or mechanisms may be operated. It is also sometimes called as SHAFT DRIVES.
A single large motor can be used instead of number of small motors
There is no flexibility. If the single motor used develops fault, the whole process will be stopped.