What is the no load characteristic of the separately excited DC generator?

Let us consider a separately excited DC generator giving its no load voltage E0 for a constant field current. If there is no armature reaction and armature voltage drop in the machine then the voltage will remain constant.

How the OCC curve can be made up?

The data for O.C.C. curve is obtained by operating the generator at no load and keeping a constant speed. Field current is gradually increased and the corresponding terminal voltage is recorded. However, even when the field current is zero, some amount of emf is generated (represented by OA in the figure below).

How do you define separately excited generators?

A separately excited DC generator is the one whose field winding is supplied by an independent external DC source (like a battery). The magnitude of generated voltage depends upon the speed of rotation of armature and the field current, i.e., greater the speed and the field current, higher is the generated voltage.

What are the characteristics of a separately excited DC generator?

The external characteristic of a separately excited generator is the curve between the terminal voltage (V) and the load current IL (which is the same as armature current in this case). (a) The armature reaction weakens the main flux so that actual e.m.f. generated E on load is less than that generated (E0) on no load.

Which of the following characteristics of a DC generator is called Regulation curve?

Regulation curve /Performance curves: The ability to deliver output voltage of a DC generator with the change in load current from no load to full load. The lower the voltage regulation will be, the performance of the generator will be better. Also called as armature characteristics.

What is meant by generator characteristics?

D.C. Generator Characteristics: This curve shows the relation between the generated e.m.f. at no-load (E0) and the field current (If) at constant speed. It is also known as magnetic characteristic or no-load saturation curve.

What is OCC generator?

Digital ElectronicsElectronics & ElectricalElectron. The open circuit characteristics (O.C.C) or magnetization characteristics is the curve that shows the relationship between the generated EMF at no-load (E0) and the field current (If) at constant speed.

What is the primary difference between the OCC of a separately excited and self excited shunt DC generator?

In a separately excited (S.E.) machine, the field winding is connected to a separate voltage source while, in a self excited generator field winding is connected across the armature terminals (provides its exciting current) .

How would you define separately excited DC generator and self excited DC generator?

In a separately excited (S.E.) machine, the field winding is connected to a separate voltage source while, in a self excited generator field winding is connected across the armature terminals (provides its exciting current) . Hence, the field winding has a large number of turns with a thin conductor.

Which of the following characteristics of a DC generator is called regulation curve?

What is the purpose of separately excited DC generator?

Applications of Separately Excited DC Generators Because of their ability of giving wide range of voltage output, they are generally used for testing purpose in the laboratories. Separately excited generators operate in a stable condition with any variation in field excitation.