Abstract

The integration of solar photovoltaic power plants (SPVPPs) into power systems reduces grid inertia, challenging frequency stability during contingencies. This paper evaluates a deloaded SPVPP with fast frequency response (FFR) capability at 34% PV penetration in a modified IEEE 9-bus system. Dynamic simulations demonstrate that while a substantial 21.40% deloading level improves frequency response, the enhancements are modest - yielding just 0.42% better RoCoF (0.7824 Hz/s vs 0.7857 Hz/s) and 0.17% higher nadir (57.13 Hz vs 57.03 Hz) compared to 0% PV penetration. The optimization process achieved only a 2.18% reduction in required deloading, highlighting limited gains from reserve tuning. Economic analysis reveals a 4.85% up-regulation cost relative to generation revenue. While the proposed strategy maintains frequency within limits despite 24% inertia reduction, its marginal gains in this small test system suggest potentially greater effectiveness in larger systems where sufficient baseline inertia exists to complement the SPVPP's regulation capabilities. The study provides critical insights into the system-scale considerations for implementing SPVPP-based frequency regulation.

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