Simulation study on transient stability of AC systems considering the connected power-controlled grid-forming converters

Abstract

To investigate the evolution trend of transient stability of power-controlled grid-forming （GFM） converters connected to AC systems， generators are replaced with power-controlled grid-forming （GFM） converters and grid-following （GFL） converters of equal capacity using the IEEE 39-bus AC test system. Additionally， the number of connections and integration positions in the AC system are varied for electromagnetic transient simulations. The results indicate that power-controlled grid-forming converters exhibit superior transient stability enhancement capabilities in the integration area， especially when the replaced generators are adjacent. As the proportion of such converters in the system increases， the system’s transient stability strengthens. Furthermore， higher equivalent inertia coefficients within power-controlled GFM converters lead to weaker synchronous stability of the system， whereas higher internal damping coefficients enhance synchronous stability.

Keywords

• power-controlled gfm converter
• gfl converter
• transient stability
• equivalent inertia coefficient
• damping coefficient