A Transformer Inrush Mitigation Method for

lzmyl

Abstract—Voltage sags are major power quality problems
encountered by industries. Especially for high-tech companies
which reside within inside industry park, any voltage sag event in
the distribution system could affect many manufacturers and
inflict significant losses. The voltage sag compensator, based on
transformer-coupled series-connected voltage source inverter, is
among the most cost-effective solution to protect sensitive loads.  
For the off-line sag compensator, one important issue is the
transformer inrush at the start of sag compensation. The inrush
current may trigger the over-current protection of the
compensator inverter, and the transformer output voltage is
greatly reduced due the magnetics saturation. Oversizing the
transformer is a common approach to avoid the inrush current.
However, this would dramatically increase the size and weight of
the sag compensation system. This paper proposes a new
technique for mitigating the inrush of the coupling transformer
and preserving the output voltage for effective sag compensation.
Detailed explanations of the proposed inrush mitigation
technique are presented, and the effectiveness of the proposed
scheme is verified by laboratory test results. The inverter-assisted
commutation sequence of the bypass thyristors for fast start of
the compensator is also presented and verified by test results.

hypo_qu

努力的看看，希望能看明白

[ 本帖最后由 hypo_qu 于 2008-11-20 14:53 编辑 ]