Analytical methods for determining a system configuration acceptable from viewpoints of both short circuit current and voltage stability

✍ Scribed by Yasuyuki Tada; Hiroshi Okamoto; Atsushi Kurita; Yasuji Sekine

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 177 KB
• Volume: 124
• Category: Article
• ISSN: 0424-7760
• DOI: 10.1002/(sici)1520-6416(199808)124:3<30::aid-eej4>3.0.co;2-n

✦ Synopsis

Generally, improving voltage stability to power demand increase tends to increase short circuit capacity. In this paper, two methods are proposed in order to obtain appropriate system separation points that minimize short circuit capacity increase and voltage stability decrease.

Considering the Q-e network that expresses the relation of voltage and reactive power, voltage sensitivity is equivalent to an element of the system impedance matrix. A fast calculation procedure for the change of the impedance matrix element due to bus connection changes has been proposed. It can be applied to the calculation of both the voltage sensitivities and the short circuit capacity. The results give information on the most appropriate separation points among the designated candidates, taking account of short circuit capacity problems and voltage stability considerations.

The second method proposed uses a linear programming technique with variable line impedances and the objective function minimizing the short circuit capacity subject to bus voltage dip constraints. This gives information on the preferable separation points in large and complicated systems. Some practical procedures are also given.