Equivalent Circuit DefinitionAn equivalent circuit of a transformer is a simplified model used to calculate impedance, resistance, and leakage reactance.Primary Side Equivalent CircuitTo draw the equivalent circuit referred to the primary side, use the general equivalent circuit and modify it for primary side calculations.Excitation BranchThe primary current splits into no-load and load components, requiring a parallel path in the equivalent circuit known as the excitation branch.Approximate Equ