Abstract

The paper discusses the attenuation of rotor angle oscillations in micro-synchronous generators in the presence of a fault, operating near PV generation units following a proposed control scheme. The X/R ratio is lower in distribution systems, making power transfer more difficult, especially during conditions of rapid active power delivery. In this context, this paper proposes a post-fault active power recovery scheme to be applied to PV units in a distribution system, specifically designed to act during severe disturbances. The proposed control scheme implements a DC voltage reference ramp during the active power recovery stage of the PV unit, aiming to prevent a sudden increase in the inverter’s active power output. In distribution systems with limited transfer capacity, the increased active power of the inverter could flow into the synchronous machine, leading to an increase in rotor angle oscillations-a phenomenon not observed in a high-voltage transmission grid. The proposed scheme is experimentally tested, comparing its performance against low-voltage ride-through (LVRT) requirements established by various grid codes. The results demonstrate the effectiveness of the proposed control scheme in reducing synchronous machine post-fault rotor angle oscillations, performing better when compared to control schemes mandated by various grid codes.