Pre-synchronization control for parallel inverters based on power line communication

A novel wireless parallel control for inverters based on power line communication (PLC) is proposed, where the pre-synchronized control for voltage reference is realized beyond the current distribution control. The PLC modem chip is controlled by digital signal processor (DSP) to realize data transmitting and receiving operations through power line. By means of PLC and DSP algorithm, the frequency and phase of the sinusoidal voltage reference are exchanged and regulated to keep the output of the inverter modules almost in phase to improve output current sharing greatly among the inverters in parallel. Compared to the conventional wireless parallel control based on real and reactive power regulation, the proposed parallel control possesses good transient performance with lower shock during hot-swap operations due to the pre-synchronized reference signal. The synchronization regulation error is also analyzed. Theoretical analysis and experimental results are provided to verify the validity and feasibility of the proposed control.