A control method for parallel-connected multiple inverter systems

A mathematical model which governs a parallel-connected multiple inverter system is described. The multiple inverter system is controlled to feed required amounts of active and reactive power to a utility grid while suppressing the cross currents flowing between the parallel-connected unit inverters. An optimal regulator is applied to create a robust feedback control system having multi-input and multi-output. The validity of the proposed modelling and control method is confirmed by simulation.