Browsing by Author "Sanni, S. O"

Now showing 1 - 3 of 3
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    Identifying interaction boundary of inverter-based generation in assessing system strength of power grids using relative electrical distance concept
    (Elsevier, 2024) Sanni, S. O; Mohammed, O. O; Abdullateef, A. I; Mohammed, D. S. S; Oricha, J. Y
    The increasing use of inverter-based generation (IBG) in power grids raises concern about system strength. This is partly due to the inherent interactions among multiple IBGs in close proximity to one another. This paper proposes an approach to identifying the existential boundary of interaction in a network using the relative electrical distance (RED) concept. The mathematical formulation of the RED concept to address the interaction problem among the IBGs involved utilising the power system network’s admittance matrix to capture its structural characteristics. An interaction matrix derived from the RED values of all IBG pairs was then developed to identify the interacting IBG groups. The proposed approach was demonstrated using the IEEE 39-bus system and a practical 72-bus Nigerian power grid. Results showed that RED values effectively group interacting IBGs, with values closer to 0 signifying higher interaction levels, values closer to 1 indicating lower interaction, and a value of 1 denoting no interaction. Time-domain simulations confirmed the accuracy of the approach, demonstrating that the effect of control interaction propagates proportionally to neighbouring IBGs based on RED values. However, fault currents can influence the impact of control interactions. This approach, which requires less computational effort, provides a quick identification tool for potential areas of concern based on the degree of interaction, enhancing the reliability of power grids with high IBG penetration.
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    Investigating the impact of solar PV and wind energy systems on the strength of a longitudinal power grid
    (Elsevier, 2024) Sanni, S. O; Abdullateef, A. I; Mohammed, O. O; Aman, M. N; Raji, A. K; Fajuke, I. D
    The integration of inverter-based generation (IBG), such as solar photovoltaic (PV) and wind systems, presents unique challenges for power grid strength, especially in regions with limited conventional generation capacity. This study investigates the impact of such integration on the strength of Nigeria’s power grid, focusing on sparsely connected northern region with abundant renewable resources. Using the network response short-circuit ratio (NRSCR) metric, which accounts for interactions between IBGs, we assess grid strength in three case studies. Simulations were conducted with the Power System Simulation for Engineering (PSS®E) software. Static analysis reveals inherent weakness in the northern region, characterized by low short-circuit capacity. Integrating IBGs at nine strategic locations shows varying responses: strong buses (NRSCR > 10) adapt well, while weak buses (NRSCR < 10), particularly in Kano and Katsina, constrain the operational capacity of the IBGs. Furthermore, close interaction among IBGs at these locations significantly impacts the system’s dynamic response, although planned addition of conventional generators offers marginal improvement. This work highlights the potential of renewable resources to address energy shortages but also underscores the crucial need for detailed design studies at each point of interconnection (PoI), considering the longitudinal grid layout in the northern region and potential limitations imposed by IBG interactions. The findings also offer a structured approach that can be applied to power grids with comparable IBG integration levels, similar to the energy landscape of Nigeria.
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    THE IMPLICATIONS OF LOW SHORT-CIRCUIT CAPACITY ON THE STRENGTH OF POWER GRID: A NIGERIAN CASE STUDY
    (Faculty of Engineering and Technology, 2023) Sanni, S. O; Abdullateef, A. I; Mohammed, O. O
    The quest to integrate renewable energy sources (RES) into power grids arises from the need to adopt a sustainable source of energy while achieving energy security. RES such as solar photovoltaic (PV) and wind energy systems are also called inverter-based generators (IBGs) because of their inverter-interfaced connections with the grid. The inverter's quick dynamic response and low short-circuit capacity (SCC) can cause distress to the grid and potentially result in power system stability problems. This paper has assessed the SCC and system strength of the Nigerian grid based on proposed IBG integrations in the northern part of the country. A shortcircuit study was conducted, system strength was evaluated using the Network Response Short Circuit Ratio (NRSCR), and a dynamic voltage stability analysis was performed. These studies revealed that most of the proposed points on the grid have low SCC but suitable for the size of IBG integration; however, some identified weak points may affect the stability of the grid. The results of this investigation provide valuable insights on the impact of IBG integration in renewable energy-rich, SCC-deficient areas of a grid.