Nodal Analysis

Nodal Analysis with Voltage Sources

Case 1

            If a voltage source is connected between the reference node and non-reference node, we simply set the voltage at the non-reference node equal to the voltage of the voltage source.

Case 2

            If a voltage source (dependent or independent) is connected between two non-reference nodes, the two non-reference nodes form a generalized node or super node; we apply both KCL and KVL to determine the node voltages.

Note:

            A super node is formed by enclosing a dependent or independent voltage source connected between two non-reference nodes and any elements connected in parallel with it.

Principles of super node:

a.    The voltage source inside the super node provides a constraint equation needed to solve for the node voltages.

b.    A super node has no voltage of its own.

c.    A super node requires the application of both KCL and KVL.