A sensitivity-based BCU method for fast derivation of stability limits in electric power systems

For a given power system with a given contingency, called the base case, if parameters (such as real power generation) in the power system change (due to some emergency, perhaps), to form what is referred to as the new case, one would like to know how these changes will affect the system stability as quickly as possible. Also, there is a growing need of a fast approach to determine the transient stability loading limits of a system and to decide how to make generation rescheduling and load shedding in order to improve the system´s transient stability. In this paper, a sensitivity-based BCU method is proposed to resolve these problems. One feature that distinguishes the proposed method from the existing methods is that it does not rely on the invalid assumption that the mode of the controlling u.e.p. does not change for any new case. A counter-example to this assumption is also provided. The proposed method has been tested on a 50-generator system. A good, fast assessment of the system stability and the stability loading limits has been obtained