Improving the accuracy of system security assessment in highly stressed transmission grids. - Hendrik Acker; Soenke Loitz; Wolfram H. Wellssow (ISGT Europe, 2013)

Advanced model of static var compensators for power flow calculations. - Wolfram H. Wellssow; Martin Ostermann; Hendrik Acker; Willi Heckmann; Dirk Cremer (ISGT Europe, 2016)