Key Points of Synchronization Control for Multi-Inverter Parallel Operation

The parallel operation of multiple inverters is a common scenario in industrial and commercial PV-plus-storage systems; grid-connection synchronization accuracy is the core technical prerequisite for ensuring stability and preventing issues such as circulating currents and equipment error alerts. Fundamentally, parallel operation requires the output voltage, frequency, and phase of multiple units to remain highly consistent with both the grid and the parameters of the other units.
Inverters typically use Phase-Locked Loops (PLLs) to monitor grid parameters in real-time, enabling frequency tracking and phase alignment to ensure synchronized output waveforms across units. If excessive phase differences, inconsistent frequency responses, or significant output voltage amplitude deviations occur during parallel operation, internal circulating currents arise between units, directly leading to problems such as unequal power distribution, frequent overcurrent events, and protective shutdowns.
Key operational considerations: During commissioning, the power regulation response speeds, PLL parameters, and output voltage thresholds must be standardized across all units; indiscriminately paralleling new and old equipment or units from different batches is strictly prohibited. Precise synchronization control not only prevents faults and errors but also effectively balances load power, thereby enhancing the operational stability and power generation efficiency of the entire PV-plus-storage system.