Electrical Energy Sources and Their Classification

Energy Sources

Energy sources are the active elements which supply electrical energy to the circuits.

Classification of Energy Sources

Energy sources are classified into two types as independent and dependent sources. The independent sources are further divided into two types namely voltage source and the voltage source. There are four types of the dependent sources. They are
:

1. Voltage Controlled Voltage Source (VCVS)

2. Voltage Controlled Current Source (VCCS)

3. Current Controlled Voltage Source (CCVS)

4. Current Controlled Current Source (CCCS)

Classification of Electrical Sources

The classification of the sources can be observed from the above figure.

Independent Sources

Voltage Source

Voltage source is an active circuit element which delivers energy to the electrical circuit with a specified terminal voltage. If the voltage of such a voltage source is independent of the current due to the absence of internal resistance it is said to an ideal voltage source. Practically the terminal voltage is never independent of the current and has some internal resistance (or impedance) which is represented by a resistor (or impedance) in series with the source which forms a practical voltage source.

Current Source

Current source is a circuit element which delivers energy with a specified current through it. If such a source maintains constant current for any voltage then it is called as an ideal current source. An ideal current source has infinite resistance (or impedance) across it. In the practical case the current delivered by practical current source is always dependent on the voltage due to the presence of finite amount of resistance across the terminals of a current source.

Dependent Sources

The voltage or current delivered by these sources are dependent on other circuit parameters and hence they are called as dependent sources. These are classified into four types as given under along with their circuit diagrams.