The Node-Voltage Method (Nodal Analysis)

Steps

1. Identify all essential nodes (n)
2. Pick one node as a reference voltage (ground), label node voltages
3. Write KCL or constraint equations (as a function of nodal voltages) for n-1 nodes (e.g. $\frac{V_1-V_2}{R_1}+I_1=0$)
4. Solve the set of equations for all nodal voltages

Advantages

• Provides an algorithmic method to solve problems (so it’s easier to know where to start)
• Usually reduces the number of equations needed (compared to KVL/KCL only)
• You don’t need to keep track of branch currents

Special Cases

• Current source in branch
  • Use definition of current source in KCL equation at node
• Super-Node (voltage source between branches)
  • Voltage source not connected to ground
  • Combine KCL equations for each node in super node
  • Write a constraint equation for the supernode