Impact of Inverter Control and Solar Photovoltaic Integration on Small Signal Stability Augmented with Battery: Modal Analysis Approach

Abstract

The increasing penetration of renewable energy sources, particularly solar photovoltaic (PV), poses significant challenges to grid stability due to the reduction in system inertia. This paper evaluates three inverter control strategies—𝑽𝒂𝒄 − 𝚽, 𝑽𝒂𝒄 − 𝐏, and 𝑷 − 𝑸 —using modal analysis and participation matrix evaluation to identify the most effective approach for enhancing small signal stability. Among these, the 𝑷 − 𝑸 control strategy emerges as the best-performing technique, with a notable eigenvalue improvement from −𝟎. 𝟔𝟐 + 𝟗. 𝟔𝟎𝟕𝒊 (𝑽𝒂𝒄 − 𝚽) to −𝟏𝟒. 𝟕𝟗 + 𝟎. 𝟔𝟔𝟖𝒊, achieving an exceptionally high damping ratio of 0.998. The participation matrix analysis highlights the dominance of active power control in stabilizing critical modes, further validating the superior performance of 𝑷 − 𝑸 control. Moreover, the impact of solar PV has been demonstrated and enhancement of system stability utilizing Battery Energy Storage System (BESS) has been shown in this paper.