This paper presents the control strategy for parallel operation of an inverter to eliminate DC & AC circulating current. This paper also analyses the cross-current between parallel connected inverter due to the difference in output voltage magnitudes of inverters, the phase difference of inverter output voltages and difference in DC offsets present in inverter output voltages. The circulating current flows between inverters due to DC-offset voltage and fluctuation of AC output voltages. This strategy uses the fundamental voltage and phase droop scheme to allow the inverters to share their load currents and uses a DC-offset droop scheme in order to eliminate DC circulating current. AC component of current is divided into two parts i.e. an active component of the current ${\mathit{I}}_{\mathit{p}}$ and $\mathit{a}$ reactive component of the current ${\mathit{I}}_{\mathit{q}}$. These two components of AC currents are used to eliminate AC circulating current. The validity of the proposed control strategy is investigated through MATLAB simulation and the results obtained satisfactorily.

本文介绍了逆变器并联运行的控制策略，以消除直流和交流环流。本文还分析了由于逆变器输出电压幅值的差异、逆变器输出电压的相位差以及逆变器输出电压中存在的直流偏移差异而导致的并联逆变器之间的交叉电流。由于直流偏置电压和交流输出电压的波动，循环电流在逆变器之间流动。该策略使用基本电压和相位下垂方案来允许逆变器共享其负载电流，并使用直流偏移下垂方案来消除直流循环电流。电流的交流分量分为两部分，即电流的有功分量${\mathit{一世}}_{\mathit{磷}}$ 和 $\mathit{一种}$ 电流的无功分量 ${\mathit{一世}}_{\mathit{q}}$. 交流电流的这两个分量用于消除交流环流。通过MATLAB仿真研究了所提出的控制策略的有效性，并获得了令人满意的结果。