Assessing the Impact of Energy Storage on Nigeria's Power System Stability: A Dynamic Simulation Study

The Nigerian power system is characterized by recurrent blackouts and inefficient use of existing generation capacity. The study presented herein explores the integration of energy storage to strengthen the Nigerian grid. The control system was simulated using MATLAB/Simulink, whereas the power system models were simulated using DIgSILENT PowerFactory. Four simulation cases are investigated; they are (1) base case (no energy storage), (2) battery energy storage system, (3) pumped hydro storage, and (4) combined hybrid energy storage system. In the base case, the system was not stable; frequency deviated from the set point by 0.8 Hz, voltage stability index (VSI) dropped below 0.9, and there was over a 30% chance of a blackout. The energy storage system helped compensate over a short period of time, and system performance improved to yield less than 0.3 Hz frequency deviation and less than a 15% chance of blackouts. PHS aided in supporting the system over a prolonged period but did not impact system stability significantly. The combined energy storage systems had the highest stability, below 0.2 Hz frequency deviations, over 0.95 VSI, and less than a 10% chance of blackouts; they achieved over 92% efficiency integrating renewables into the grid. The hybrid storage systems gave a complete solution to mitigate short-term faults and long-term system deviations. Energy storage, especially hybrid systems, is no longer a preference but a necessity to transform the Nigerian power system and enhance stability and security of power supply.