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In the condition of connecting large scale
doubly-fed induction generators (DFIGs) into weak grid,
the closely coupled interactions between wind generators
and power grid becomes more severe. Some new fault
characteristics including voltage phase angle jump will
emerge, which will influence the power quality of power
system. However, there are very few studies focusing on
the mechanism of voltage phase angle jump under grid
fault in a weak grid with wind turbine integration. This
paper focuses on the scientific issues and carries out
mechanism studies from different aspects, including
mathematical deduction, field data analysis and time
domain simulation. Based on the analysis of transient
characteristics of DFIGs during the grid fault, this paper
points out that the change of terminal voltage phase angle
in DFIGs is an electromagnetism transition process, which
is different from conventional synchronous generator.
Moreover, the impact on transient characteristics of voltage
phase angle are revealed in terms of fault ride through
(FRT) control strategies, control parameters of current
inner-loop of rotor-side converter and grid strength.
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