Application of DC Generators

Application of DC Generators Points : Application of DC Generators The choice of a dc generator for a particular service depends upon its performance characteristics. Applications of various type dc generators are given below: 1. Separately Excited DC Generators These generators required separate source of supply and are, therefore, usually more expensive than self excited generators. On this account these are generally used where self excited generators would be relatively unsatisfactory. These are used in Ward Leonard systems of speed control, because self excitation would be unstable at lower voltages. Since separate excitation gives a quicker and more precise response to the changes in the resistance of the field circuit and is accordingly used where quick and definite response to control is important. 2. Series Wound DC Generators These generators have very few applications. They cannot be employed for power supply on account of their rising voltage characteristics. They can be employed as a constant current source by making use of the drooping portion of the voltage-current characteristic. Their best application is for supplying field current for regenerative braking in dc locomotives. They are also used in series arc lighting. Another important application of these generators is as series boosters. 3. Shunt Wound DC Generators Such generators with field regulators are used from light and power supply purposes. These are also used for charging of batteries because they can be made to give constant output voltage. 4. Cumulative Compound Wound DC Generators Over-compounded type dc generators are generally used for lighting and power services because over-compounding compensates voltage drop in the distribution lines and thus the voltage at the consumer terminals remains more or less constant. 5. Differential Compound Wound DC Generator It is a constant current generator and finds an useful application as an arc welding generator where the generator is practically short-circuited every time the electrode touches the metal plates to be welded.