Regulatory Drivers, Case Studies, and Market Assessment of E-STATCOM Technology for Power System Stability

Sammanfattning

The increasing penetration of renewable energy into the grid has resulted in a high inverter contribution, which is transforming power systems and creating new challenges for maintaining voltage and frequency stability. The reduction in the number of conventional synchronous generators reduces system inertia and weakens the grid, increasing the risk of system faults, voltage instability, and frequency deviations. To solve these challenges, advanced grid support technologies are required. The energy static synchronous compensator (E-STATCOM) has emerged as a promising solution due to its ability to provide both dynamic reactive power compensation and active power support through integrated energy storage. This thesis investigates the regulatory drivers, power system case studies, and market positioning of E-STATCOM technology in modern power systems. A qualitative research methodology is adopted, combining document analysis of international standards, national grid codes, and regulatory frameworks with several power system case studies and a comparative assessment of alternative grid support technologies. The study examines recent power system disturbances associated with system splitting, weak grids, and low-inertia conditions to identify operational scenarios in which E-STATCOM can improve grid stability. Furthermore, market competitiveness, technology providers, and electricity market structures are evaluated to assess the technology's commercial relevance. The results indicate that stricter grid codes and power system regulations are driving demand for the technologies deployment. Key features needed include fast voltage support, fault ride-through capability, synthetic inertia, and frequency response services. Analysis of recent disturbances in Brazil, the Iberian Peninsula, Chile, and South Australia demonstrates that inadequate voltage support, low system inertia, and limited dynamic response capabilities can significantly contribute to power system failures. E-STATCOM technology addresses these challenges by combining the dynamic voltage regulation strengths of conventional STATCOM systems with active power support from a supercapacitor, enabling it to contribute to both voltage and frequency stability. Comparative assessment shows that E-STATCOM offers favorable technical performance compared with other flexible AC transmission system (FACTS) shunt-connected devices. However, its deployment remains limited due to technological maturity, implementation complexity, and the early stage of market development. Current commercial applications are available only in Germany, where transmission system operators (TSOs) are deploying E-STATCOM facilities to support a power system that is dominated by renewable energy. The study concludes that the transition from physics-based stability provided by synchronous machines to control-based stability provided by power electronic converters necessitates advanced grid support technologies. E-STATCOM demonstrates strong alignment with emerging regulatory requirements and operational needs, making it a promising technology for enabling reliable and resilient integration of renewable energy into future power systems.