Application of Grid-Enhancing Technologies for Stability Improvement in Low-Inertia Power Systems: A Case Study from Egypt

The Egyptian Electricity Transmission Company (EETC) conducted an in-depth study to assess the systemic implications of large-scale integration of RES into the Egyptian grid, with a specific focus on system stability under both normal and perturbed operating conditions. This paper presents a comprehensive summary of the full system study. The paper highlights the performed analyses including the steady-state, voltage stability, and transient stability analyses.

Furthermore, the study is designed to identify and characterize the suite of requisite Grid

Enhancing Technologies (GETs) that are essential for optimizing the hosting capacity of the grid, ensuring compliance with established reliability criteria, and mitigating potential violations associated with thermal limits, voltage instability, and system security margins.

Multiple scenarios for the 2028–2029 planning horizon were analyzed, covering a wide range of operating conditions such as different load levels, RES dispatch patterns, seasonal variations, and interconnection operational assumptions. Both steady-state and dynamic analyses were performed, including load flow, N-1 contingency analysis, voltage stability, short-circuit analysis, and transient stability studies.

Dynamic modeling of Inverter Based Resources (IBRs) was implemented using generic

RMS/phasor-domain positive-sequence models consistent with the Egyptian Grid Code and aligned with IEEE Std. 2800. The dynamic model set-up is appropriate for early-stage transmission planning studies intended to screen feasible renewable integration levels, identify critical contingencies, and compare mitigation options before detailed vendor-specific models become available. Generic dynamic models were parameterized to provide primary frequency response, mitigate momentary cessation, and ensure compliance with voltage and frequency ride-through requirements.

The study was carried out using a power system analysis RMS/phasor-domain environment platform. The results indicate that the integration of the RES projects introduces transient stability challenges under critical contingency events. Notably, the system exhibited sustained low-frequency oscillations in the post-disturbance transient responses. These issues indicate inadequate damping and limited fast-reactive support.

To address these stability deficiencies, a broad range of GETs were examined through extensive sensitivity analyses, including synchronous condensers, STATCOMs, and BESS. The comparative assessment considered damping improvement, post-fault voltage recovery, shortcircuit constraints, and practical siting considerations. The screening results showed that strategically located STATCOMs provide the most robust improvement in dynamic voltage support and oscillation damping without worsening short-circuit levels, while BESS remains a candidate technology for later project phases when plant-specific controls are defined..

Post-reinforcement assessments demonstrate that the implementation of the proposed GETs successfully mitigates the stability issues identified in the early-stage planning study. With the selected combination of of transmission reinforcements and dynamic reactive support in service, the system meets applicable reliability criteria across all studied scenarios and contingency events. The enhanced fast-reactive support, improved damping, and augmented frequency response provided by the GETs eliminate sustained oscillations, restore adequate stability margins, and ensure secure system operation under high renewable energy penetration conditions.