Decoupling control strategy of single phase SPWM parallel inverter

In this paper, based on the analysis of the equivalent output impedance and parallel model of single phase SPWM inverter, a decoupling control strategy of parallel inverter system is proposed. The output power is decomposed into active power and reactive power to regulate the amplitude and phase of the reference signal. A three-phase balanced current is constructed according to the instantaneous reactive power theory to decompose the active and reactive components of inverter output power and its implementation block diagram is given. By the uniform distribution of the active power and reactive power within the inverters, the parallel system can have a good current-sharing performance. Experimental results of 110V/2KVA parallel inverter system show that the decoupling control strategy is feasible and efficient.