A method of the identification of weak and/or strong nodes of an electric power system

摘要

The subject of the invention is a method for the identification of weak and/or strong nodes of an electric power transmission system.;The inventive method consists in subjecting the electric parameters characterising nodes and branches of an electric power transmission system to computational treatment in order to obtain equations of power flow in all nodes of the system at assumed 100 percent system load value. Then earth is taken as the reference point, and nodal impedance values are computed for all nodes of the system, which values are then used to construct a P-Q curve which presents the functional relation between the system's reactive and active load. In the next operation, the nodal coefficient of voltage stability is determined as the relative distance between the base load point of that node and the critical point on the P-Q curve which is situated most closely to the base point. The numerical value of this coefficient is compared with a threshold value considered to be a safe margin to maintain voltage stability for a given node.