Comparison of Voltage Sag Generators for Wind Power System

javen88

Comparison of Voltage Sag Generators for Wind Power System

rrshengqi

Abstract—Low voltage ride through (LVRT) capability is
required by new power system operating codes, then voltage sag
generator (VSG) is generally used to simulate different voltage
sag faults. The work principles of transformer and bidirectional
switches based VSG and full-power converter based VSG are
explained and discussed, the former can choose relay, thyristor
or IGBT as bidirectional switches, and the comparison research
of several VSG solutions is carried out by analysis and
experiment. The experiment results make out that the full-power
converter based VSG is powerful but its control is complex; the
transformer and bidirectional switches based VSG has simple
structure and high reliability, can simulate various types of
voltage sag faults, and the voltage transition between normal and
fault operation is smooth, then provide favorable conditions to
verify the LVRT capability of wind power system.
Keywords-wind power system; low voltage ride through
(LVRT); voltage sags; voltage sag generator (VSG);
autotransformer; bidirectional switches; full-power converter