Unbalanced power flow calculation of a power system containing a variable-speed generator

✍ Scribed by Junji Tamura; Masahiro Kubo; Toshiyuki Nagano

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 298 KB
• Volume: 134
• Category: Article
• ISSN: 0424-7760
• DOI: 10.1002/1520-6416(200102)134:3<34::aid-eej5>3.0.co;2-w

✦ Synopsis

There are some factors that render a power system network unbalanced: UHV transmission lines in which three-phase transmission lines are not transposed, an unbalanced transformer, unbalanced load as well as sustained unbalanced faults. On the other hand, the number of variable-speed generators used in pumping-up power stations has recently been increasing in Japan. This paper presents a new means of calculating unbalanced power flow of a power system which contains variable-speed pumping-up generators. This new technique is based on the phase coordinate method, because a power system which has elements of unsymmetrical impedance can easily be analyzed by using it.

In this paper, phase coordinate models of the variable-speed generator and its secondary exciting circuit, composed of a GTO converter/inverter, are analyzed first. Procedures of power flow calculation of unbalanced power systems follow.