A current decoupling parallel control strategy of single phase inverter with voltage and current dual closed-loop feedback

The output characteristics of a single phase inverter with voltage and current dual closed-loop feedback control are analyzed and the equivalent model of the parallel operating single phase inverter system is introduced. The relationship between the circulating current and the amplitude/phase of inverter reference signal is analyzed, based on which a current decoupling control strategy of parallel operating inverter system is proposed. The active and reactive components of the inverter output current can be decomposed and the decoupled control of inverter reference amplitude and phase can then be carried out. Furthermore, a three-phase balance current is constructed according to instantaneous reactive power theory to decompose the active and reactive components of output current and its block diagram is given. The prototype is developed and the control of two parallel operating 2kVA inverters is realized. The experimental results show its feasibility and effectiveness.