"Series Compensated Step-down AC Voltage Regulator using AC chopper with transformer"
H.J.Ryoo, J.S.Kim, G.H.Rim, J.W.Jeon, D.S.Kim
, KIEE INTERNATIONAL TRANSACTIONS ON ELECTRICAL MACHINERY and ENERGY CONVERSION SYSTEMS
, VOL. 5-B
, NO. 3
, pg. 277-282
, Sep.2005