Distributed generations systems (DGs) are usually parallel-connected to supply various kinds of loads in microgrids. In particular, the presence of nonlinear loads results in harmonic load currents. In addition, unmatched feeder line impedances cause disproportionate sharing of harmonic power and reactive power among online DGs. To solve these challenges, this paper proposes a novel model predictive virtual capacitance control scheme. It relies on the symmetrical components decomposition of distorted load current waveform into positive and negative sequences. This control method can work accurately without accurate feeder line information, and can be implemented with a sparse communication network. The performance of the proposed method is verified through several test scenarios on an AC microgrid.