M. Aghamohammadi, S. S. Hashemi, M. S. Ghazizadeh,
Volume 7, Issue 1 (3-2011)
Abstract
This paper presents a new approach for estimating and improving voltage stability margin from phase and magnitude profile of bus voltages using sensitivity analysis of Voltage Stability Assessment Neural Network (VSANN). Bus voltage profile contains useful information about system stability margin including the effect of load-generation, line outage and reactive power compensation so, it is adopted as input pattern for VSANN. In fact, VSANN establishes a functionality for VSM with respect to voltage profile. Sensitivity analysis of VSM with respect to voltage profile and reactive power compensation extracted from information stored in the weighting factor of VSANN, is the most dominant feature of the proposed approach. Sensitivity of VSM helps one to select most effective buses for reactive power compensation aimed enhancing VSM. The proposed approach has been applied on IEEE 39-bus test system which demonstrated applicability of the proposed approach.
D. S. Javan, H. Rajabi Mashhadi,
Volume 7, Issue 4 (12-2011)
Abstract
Deregulation of power system in recent years has changed static security assessment to the major concerns for which fast and accurate evaluation methodology is needed. Contingencies related to voltage violations and power line overloading have been responsible for power system collapse. This paper presents an enhanced radial basis function neural network (RBFNN) approach for on-line ranking of the contingencies expected to cause steady state bus voltage and power flow violations. Hidden layer units (neurons) have been selected with the growing and pruning algorithm which has the superiority of being able to choose optimal unit’s center and width (radius). A feature preference technique-based class separability index and correlation coefficient has been employed to identify the relevant inputs for the neural network. The advantages of this method are simplicity of algorithm and high accuracy in classification. The effectiveness of the proposed approach has been demonstrated on IEEE 14-bus power system.
Lambe Adesina, Ahmed Olaoye, Olalekan Ogunbiyi, Khalil D. Dalegan,
Volume 22, Issue 3 (9-2026)
Abstract
Analyzing power systems for network planning and operation requires a thorough understanding of network parameters to evaluate system performance. Effective monitoring and management depend on power flow analysis and contingency assessment. This paper examines an electric power system with a focus on these critical aspects to enhance planning and operational efficiency. A regional transmission network is used as a case study, with simulations conducted using Power System Simulation (PSS) software. The network’s performance under various N-1 contingency cases was evaluated, emphasizing voltage stability and line loading violations. Vulnerable buses were identified through separate voltage and line loading violation analyses. This study also examines the interaction between STATCOM and the network during N-1 contingencies, demonstrating its effectiveness in improving voltage stability and reducing overloads. To assess voltage collapse proximity and outage effects on reactive power margin, QV curves were plotted for the most affected buses. STATCOM was placed at each affected bus to determine optimal performance, mitigating N-1 contingency effects. By effectively compensating for reactive power, the network’s power handling capacity was enhanced. Consequently, applying STATCOM significantly improved voltage profiles and increased the power handling capacity of affected buses before and after contingency scenarios, ensuring a more stable and resilient transmission network.
