Enhanced Current-Limiting Droop Controller for Grid-Connected Inverters to Guarantee Stability and Maximize Power Injection Under Grid Faults

Droop-controlled inverters are widely used to integrate distributed energy resources (DERs) the smart grid and provide ancillary services (frequency voltage support). However, during variations or faults, droop control scheme should inherit a current-limiting property protect both inverter DER unit. In this brief, novel structure of recently developed (CLD) controller is proposed accomplish two main tasks: 1) guarantee current limitation with maximum power injection faults 2) rigorously asymptotic stability any equilibrium point in given bounded operating range closed-loop system for grid-connected inverter. Since unit can be utilized under enhanced CLD then inspired by latest fault-ride-through requirements, it further extended support faulty via reactive power. This achieved simply adjusting reference opposed existing schemes that require adjustment real powers. Hence, unified normal grids simplified mechanism experimentally verified brief.