An original finite element method for calculating two-axis transient parameters of solid rotor turbine-generators, is presented. Eddy current effects are lumped into equivalent damper circuits representing layers of massive conductors within the rotor. The time variation of machine parameters of a two-axis model is determined and the equivalent circuits obtained are tested by comparing the two-axis and finite element simulations. The two-axis equivalent circuits can simulate a wide range of operating conditions, with appropriate modification of the magnetizing inductances.