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Overvoltage phenomena caused by disconnecting motor‐loads on power line with open‐phase
Author(s) -
Himeno Takashi,
Okamura Yukio,
Asada Minoru,
Nakamura Toshihiro
Publication year - 1994
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/eej.4391140310
Subject(s) - overvoltage , electrical engineering , power factor , capacitor , transmission line , engineering , electrical impedance , ac power , electric power transmission , transformer , voltage
This paper describes overvoltage caused by disconnecting a lot of motor‐loads on a power distribution line with power‐factor‐correcting capacitors during a transmission line open‐phase. The overvoltage phenomena are studied by a field test, a steady‐state analysis and a transient analysis. Experimental results show that the line‐to‐line voltage on a 6.6 kV distribution line with an open‐phase 22 kV transmission line amounts to 1.7 per unit. The overvoltages are caused by two types of resonance. One is the linear circuit resonance between the power‐factor‐correcting capacitors and the secondary side impedance of motors. The difference between positive components and negative ones of the impedance produces the resonance. The other is the nonlinear circuit resonance between the power‐factor‐correcting capacitors and the saturated reactances of a transformer.