A novel controller for parallel operation of inverters based on decomposing of output current

In this paper, a novel control scheme for parallel-connected inverters without communication wires is presented. This paper analyses the cross current between parallel-connected inverters, and divides the current into two parts: AC cross current and DC cross current. In the previous literature, almost all the control schemes try to eliminate the AC cross current. DC cross current, however, is neglected. In this paper a new technique without control interconnections based on decomposing of output current is proposed, it uses fundamental voltage and frequency droop method to allow inverters to share the load current and uses a novel DC-offset voltage droop method to eliminate the DC cross current. From the analytical models and experiment results, the proposed controller for parallel operation of inverters is verified.