Abstract: Targeting the inefficiencies in storage battery capacity verification and large-scale impact of faults in conventional substations, an online capacity verification system based on a grouped parallel architecture and bidirectional LLC (Inductor-Inductor-Capacitor) resonant conversion is proposed. The system reconfigures a 108-cell (2 V each) series battery bank into nine independent 12 V modules, which are then connected in parallel to the DC bus via bidirectional LLC resonant converters to achieve charging and discharging control and fault isolation. A dynamic capacity model and parallel capacity verification strategy are developed in conjunction with edge computing terminals. Validation at a 110 kV substation demonstrates 90% reduction in capacity verification time with dual-group parallel operation, 100% success rate in fault isolation, 50% decrease in annual average operation and maintenance costs, and 100% accuracy in automated capacity verification report generation. By synergizing the grouped architecture with edge computing, this system achieves the transition of storage battery capacity verification from manual operations to fully automated and intelligent online operation, providing critical technical support for smart substation construction.

Key words: storage battery, grouped architecture, online capacity verification, bidirectional conversion, LLC resonant, edge computing