The operation modes of grid-connected inverters startup, grid-connected power generation, standby, normal shutdown, fault handling, and dual-mode operation (grid-connected/islanding). Startup Mode Transitions from off state to grid-connected preparation stage Inverter continuously monitors PV module power Automatically switches to grid-connected generation when DC voltage reaches set value (e.g., 520V) Grid-Connected Power Generation Mode Core function is converting DC from PV modules to AC for grid integration Output AC must match grid in frequency, phase, and amplitude Uses Maximum Power Point Tracking (MPPT) technology to ensure maximum power output under any light and temperature conditions Standby Mode Inverter enters standby when grid voltage and frequency are normal but PV output is insufficient for continuous grid connection System power is checked every 5 minutes, switching back to grid generation if conditions are met Normal Shutdown Mode As sunlight weakens and PV output drops below threshold, inverter enters normal shutdown Voltage is turned off, grid-side contactor is disconnected, separating from the grid Manual stop requires re-initiation of grid connection Fault Handling Mode Inverter immediately disconnects from grid and triggers alarm upon system fault LCD displays fault information Automatically checks for grid reconnection conditions after 5 minutes, otherwise remains shutdown until manual repair Dual-Mode Operation Supports both grid-connected and isl