Can the output impedance of an inverter be designed capacitive?

In this paper, it is shown that the output impedance of an inverter can be designed to be capacitive via the feedback of the filter inductor current through an integrator. Such inverters are called C-inverters (inverters with inductive and resistive output impedances are called L-inverters and R-inverters, respectively). Moreover, a recently-proposed robust droop controller is further developed and applied to inverters with capacitive output impedances to achieve accurate sharing of real power and reactive power and to maintain the output voltage within the desired range. Simulation results are provided to demonstrate the feasibility and the performance. Under the same conditions, simulation results show that an inverter achieves lower total harmonic distortion (THD) when it is designed to have a capacitive output impedance than when it is designed to have a resistive or inductive output impedance.