2Paul J P, Leost J Y, Tesseron J M. Survey of the secondary voltage control in France : present realization and investigations. IEEE Trans. on Power Systems, 1987, 2 (2).
3S Coris, M Pozzi, C Sabelli, et. al. The coordinated automatic voltage control of the Italian transmission grid, Part Ⅰ and Part Ⅱ. IEEE Trans. on Power Systems, 2004, 19(4).