A comparison of Lorentz gauge formulations in eddy current computations

The modified vector potential provides a computationally acceptable formulation for many problems but leads to difficulties when one has to cope with (a) interconductor interfaces and (b) problems where the frequency conductivity product is low. The authors investigate the use of the Lorentz gauge as a curative to the difficulties encountered by the modified magnetic vector potential formulation. The uniqueness conditions are examined, and three different implementations of the Lorentz gauge are compared and contrasted. A classically motivated Lorentz gauge formulation is shown theoretically to produce unique solutions and in practice to produce results comparable to those given by other researchers. The limitations of the modified vector potential formulation have been overcome with the minimum of overhead