This applet shows the steps to plot the Potier diagram for the synchronous machine, given its no-load characteristic [math]E_0=f(M)[/math] with [math]E_0[/math] no-load voltage and [math]M[/math] excitation m.m.f., its leakage reactance [math]X_\sigma[/math] and relation between the armature current [math]I[/math] and m.m.f. [math]M_i[/math]. Once the diagram is completed, you can check the influence of both the machine parameters and the armature current power factor.