Distance-conscious power flow and dynamic stability analysis of an IEEE 9-bus system with synchronous generators and grid-forming converters under a linear controller

This paper presents new insight into assessing the efficiency of grid-forming control methods with respect to electrical distance and point of interconnection. Large loads such as modern data centers introduce operational challenges due to high power demand, rapid ramp rates, and stringent fault ride-through requirements. These characteristics influence the performance of grid-forming technologies, including virtual synchronous machines (VSMs) and droop-based controllers, under varying system conditions and transmission distances. The study examines these effects in a system predominantly supplied by synchronous generators using the IEEE 9-bus test network, with emphasis on long transmission lines. System stability as a function of electrical distance is assessed in terms of voltage regulation, frequency response, and fault ride-through capability, and is compared with conventional synchronous-generation-based behavior. Simulation results indicate that synchronous generators maintain superior fault ride-through performance, reducing disturbance impact by up to a factor of 20, while grid-forming converters provide enhanced voltage support and improved post-disturbance recovery through fast reactive-power control. The influence of grid topology and electrical distance on the effectiveness of voltage-control strategies is also analyzed. The findings highlight the benefits and limitations of grid-forming control in long-distance transmission systems and underscore the need for advanced control strategies to ensure stability as electrical distance increases.