9[1]Woodley N H, Morgan L. Sundaram A. Experience with an inverter-based dynamic voltage restorer[J]. IEEE Trans. on Power Delivery, 1999,14(3):1181-1186.
10[2]Conrad L E, Bollen M H J. Voltage sag coordination for reliable plant operation[J]. IEEE Trans. on Industrial Application, 1997,33(6): 1459-1464.