Implemented according to [1].
References:
[1] P. Kundur, N. J. Balu, and M. G. Lauby, Power system stability and control. New York; London: McGraw-Hill, 1994.
function ABCtoDQ_Kundur input Real f_abc[3]; input Real theta; output Real f_dq[2]; end ABCtoDQ_Kundur;