As can be seen, in The V Formulation and The Vm Formulation, introducing a scalar potential makes it possible to formulate Maxwell’s equations into a single Poisson’s equation. Maxwell’s equations can also be formulated with vector potentials. For example, by introducing the magnetic vector potential A and defining B = ∇ × A, the magnetic form of Gauss’ law (∇ ⋅ B = 0) is inherently satisfied since ∇ ⋅ ∇ × A = 0 always holds.

The A formulation is used by The Magnetic Fields Interface and The Magnetic Fields, Currents Only Interface in the AC/DC Module. Depending on specific cases (static, quasistatic, transient, and time harmonic), different study types in different dimensions of The Magnetic Fields Interface are available. For more details, see the Theory for the Magnetic Fields Interface. The A formulation is the most popular formulation used in low-frequencies electromagnetics. Therefore, The Magnetic Fields Interface is the recommended primary choice for modeling magnetic fields involving source currents. However, other formulations are also possible and are useful for specific circumstances.