Power system weak bus identification based on voltage distribution characteristic

In this paper, the weak buses of power system are identified by voltage distribution characteristic indicators in the case of load fluctuation. First, the probabilistic load flow (PLF) based on Latin hypercube sampling (LHS) is applied to obtain random load states and voltage of each bus. The samples obtained by LHS can basically cover the whole load variation region. Combined with the N-1 fault analysis method, the collapse states of power system caused by different load fluctuation are researched. Second, the distribution characteristics of collapse bus voltage are analyzed by normal distribution probability paper test method. The result is that the collapse bus voltages obey normal distribution. Third, different voltage stability risk assessment indicators are proposed to identify the weak buses in power system. These indicators are proposed from voltage distribution characteristics, voltage change rate and voltage sensitivity point of view. Finally, the proposed method is tested on IEEE 30 bus system. The results show that the identification method of weak buses is very valuable for fast identification of weak buses in the case of load random fluctuation.