A novel approach for the identification of critical nodes and transmission lines for mitigating voltage instability in power networks

Voltage collapse is a major issue combating the effectiveness and optimal operation of modern power systems in recent times. This is a great threat to the security and reliability of modern power systems and, in recent times, it has been a growing concern for power system engineers, researchers and utilities. A prompt identification of transmission lines whose outage could lead to a cascading failure and the sets of nodes where voltage collapse could erupt, during critical outages, is therefore a vital issue for a reliable and secure power system operation. An alternative approach to solving these problems is therefore presented in this paper. The problem is viewed from the graph-theoretical perspective, considering the topological properties of power networks. Application of the fundamental circuit theory is employed and the bus-to-line matrix (BLM) is formulated. This matrix provides clearer insights into the interconnections of the components within the network. This valuable information is captured and used for identifying the critical elements where a suitable location for reactive power support could be placed to avoid voltage collapse of the network. The effectiveness of the proposed approach is tested using a simple 10-bus power network. The results obtained are compared with those obtained from the existing approaches. The results obtained show a strong correlation and agreement between the proposed and the existing approaches.