Steady-state and transient parameter computation for wound field synchronous machines

In this paper, an analytical approach is presented to compute steady-state and transient parameters of salient-pole wound field synchronous machines. These parameters are derived based on the following two analytical field solutions in the air gap: i) the magnetic field distribution due to the field current; ii) the magnetic field distribution due to the armature reaction, which is obtained from the air-gap permeance distribution. Both the air-gap magnetic field distribution by the field current and the air-gap permeance distribution for the armature reaction are determined by means of conformal mapping. Results from the proposed analytical approach are validated by those from the finite element analysis (FEA). The performance at the rated operation based on the steady-state parameters and the performance at the locked-rotor operation based on the transient parameters are also compared with the FEA results.