skip to main content

Title: Transient stability enhancement of electric power generating systems by 120-degree phase rotation

A method and system for enhancing the transient stability of an intertied three-phase electric power generating system. A set of power exporting generators (10) is connected to a set of power importing generators (20). When a transient cannot be controlled by conventional stability controls, and imminent loss of synchronism is detected (such as when the equivalent rotor angle difference between the two generator sets exceeds a predetermined value, such as 150 degrees), the intertie is disconnected by circuit breakers. Then a switch (30) having a 120-degree phase rotation, or a circuit breaker having a 120-degree phase rotation is placed in the intertie. The intertie is then reconnected. This results in a 120-degree reduction in the equivalent rotor angle difference between the two generator sets, making the system more stable and allowing more time for the conventional controls to stabilize the transient.
Authors:
 [1] ;  [1] ;  [1]
  1. (Portland, OR)
Publication Date:
OSTI Identifier:
864230
Report Number(s):
US 4333021
Resource Type:
Patent
Research Org:
BPA
Country of Publication:
United States
Language:
English
Subject:
transient; stability; enhancement; electric; power; generating; systems; 120-degree; phase; rotation; method; enhancing; transient; stability; intertied; three-phase; electric; power; generating; set; power; exporting; generators; 10; connected; set; power; importing; generators; 20; transient; controlled; conventional; stability; controls; imminent; loss; synchronism; detected; equivalent; rotor; angle; difference; generator; sets; exceeds; predetermined; value; 150; degrees; intertie; disconnected; circuit; breakers; switch; 30; 120-degree; phase; rotation; circuit; breaker; 120-degree; phase; rotation; placed; intertie; intertie; reconnected; results; 120-degree; reduction; equivalent; rotor; angle; difference; generator; sets; stable; allowing; time; conventional; controls; stabilize; transient; power generating; power generating; electric power; electric power; circuit breaker; circuit breaker; predetermined value; degree phase; degree phase; degree phase; phase electric; transient stability; transient stability; generator set; generator set; generating systems /307/