Integration of Enhanced STATCOMs for the Support of Wind Farms : A Feasibility Study Conducted at Hitachi Energy

Sammanfattning

As the integration of renewable energy sources increases, maintaining stability in modern power systems becomes increasingly complex due to the displacement of traditional Synchronous Generators (SGs) by converter-based generation, such as wind power. This thesis investigates how Enhanced Static Synchronous Compensators (E-STATCOMs), developed by Hitachi Energy, can support system stability under such conditions. The primary objective is to evaluate the dynamic performance of power systems with varying levels of wind penetration, both with and without the inclusion of E-STATCOMs. A combination of RMS simulations in DIgSILENT PowerFactory and time-domain Electro-Mechanical Transient (EMT) simulations in PSCAD is used. Since an E-STATCOM dedicated model is not available in PowerFactory, a Virtual Synchronous Machine (VSM) is employed as a suitable representation, tuned to emulate its behaviour. Model validation is performed by comparing PowerFactory and PSCAD results. The RMS simulations are based on the Nordic Test System, modified to include six distinct scenarios featuring different configurations of wind power and E-STATCOMs. Key stability metrics, such as frequency response, voltage recovery, and reactive power injection, are analysed following fault events. The results consistently show that the E-STATCOM improves system stability, particularly in scenarios with widespread wind power integration. Improvements include reduced voltage overshoot, faster damping of oscillations, and enhanced reactive power support. The findings confirm the potential of the E-STATCOM as a valuable tool in enhancing grid resilience. Limitations due to modelling constraints and software capabilities are discussed, and suggestions for future research, particularly involving economic analysis and higher wind penetration, are provided.