Low-Voltage Ride-Through Risk Identification for Renewable Energy in an AC/DC Receiving-End Power Grid Considering the Influence of DC System

Abstract

With the large-scale integration of renewable-energy and high-voltage direct current transmission, voltage-stability problems have gradually evolved from being dominated by the conventional load side to being jointly affected by sources and loads. Voltage dips caused by AC faults or DC commutation failures may trigger switching of renewable-energy low-voltage ride-through (LVRT) control, limit active current, weaken reactive-power support, and lead to repeated voltage dips or even cascading disconnections during recovery. Particularly in receiving-end systems with multiple DC infeed, the coupling between DC-power disturbances and renewable-energy control characteristics further aggravates LVRT risks and consequently affects voltage stability. Therefore, this paper investigates the triggering mechanism and assessment method for repeated LVRT of renewable-energy in receiving-end systems with DC infeed, thereby providing a basis for stability control and reactive-power support allocation in receiving-end grids.