Synchronization of the carrier wave of parallel three-phase inverters with virtual oscillator control

In this paper, a method to synchronize the carrier wave of parallel three-phase inverters without communication is proposed. This method is based on the digital-based virtual dead-zone oscillators coupled with each other through electrical connections between parallel inverters. These oscillators are synchronized based on the phenomenon of synchronization in networks of coupled oscillators. Thus, the carrier waves of different inverters are confirmed to be synchronized since they are generated by the oscillators. The model of the circulating current and the sufficient condition of global synchronization of oscillators are derived in this paper. The methodology for controller design is outlined based on the aforementioned analysis. Experimental results for a system with three inverters are given to illustrate the effectiveness of the proposed control.