Voltage stability discrimination system for power systems

• US 4,974,140 A
• Filed: 10/19/1989
• Issued: 11/27/1990
• Est. Priority Date: 02/01/1989
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Iba, Kenji, Suzuki, Hiroshi
• Primary Examiner(s): Wong, Peter S.
• Application Number:
  US07/423,982
• Time in Patent Office: 404 Days
• Field of Search: 363/74, 363/78, 323/205, 323/212, 323/234, 323/241, 323/283, 323/299, 323/318, 323/322, 323/349, 307/31, 307/52, 364/492, 364/495
• US Class Current: 363/74
• CPC Class Codes: H02J 3/24 Arrangements for preventing or reducing oscillations of power in networks by control effected upon a single generator H02P9/00

Abstract

A voltage stability discriminating system for a power system is disclosed for calculating a multiple load flow solution relating to a voltage stability discrimination for a power system in which the voltage stability can be discriminated fast and accurately due to the fact that the voltage stability discrimination system of the power system is constructed such that the multiple load flow solution is estimated in advance during a calculation process of the load flow calculating means. For example, the load flow calculation is made through the N-R method of a rectangular coordinates system, and after the first solution is converged and the first load flow solution (an output value of the load flow calculation means) is determined, the estimated value of the above-mentioned multiple load flow solution is examined by the load flow solution determining means so as to determine the first load flow solution as the load flow solution, or the estimated value of the above-mentioned multiple load flow solution is applied and the load flow solution is determined by performing the load flow calculation.

Claims

1. A voltage stability discriminating system for a power system for determining a multiple load flow solution for the power system with a multiple load flow solution calculating means and discriminating a voltage stability characterized in that said multiple load flow solution calculating means comprises a load flow calculating means for carrying out a load flow calculation and an optimal multiplier calculating means for calculating an estimated value of the multiple load flow solution in response to an intermediate output value of said load flow calculating means, the estimated value of said multiple load flow solution is inspected based on the output value of said load flow calculating means to determine the load flow solution.

2. A voltage stability discriminating system for a power system as set forth in claim 1, wherein the estimated value of said multiple load flow solution is applied as an initial value to the load flow solution determining means for outputting the estimated value to said load flow calculating means.