A fault occuring at the terminals of an unloaded synchronous generator opetaing at its rated voltage has resulted in the following values of the current and voltage.
I_a0 = j 2.37 p.u.
I_a1 = j 3.05 p.u.
I_a2 = j 0.68 p.u.
V_a0 = V_a1 = V_a2 = j 2.37 p.u.
The fault that has occurred is