This document is a peer-reviewed technical paper presenting text, mathematical equations, control system block diagrams, Bode plots, and hardware-in-the-loop experimental waveforms. It addresses the problem of second harmonic current distortion in islanded DC microgrids caused by the oscillatory instantaneous power of single-phase AC loads supplied through DC/AC inverters. The paper proposes a hybrid voltage and current control method for distributed energy resource grid-side converters that simultaneously regulates the DC component of the terminal voltage and the harmonic component of the output current. The proposed control architecture combines two decoupled outer control loops, a proportional-integral controller for DC voltage regulation based on a power-voltage droop characteristic, and a resonant controller tuned to twice the AC fundamental frequency for harmonic current compensation, together with an inner proportional controller for filter inductor current tracking. By relying on superposition and the inherent frequency selectivity of each controller, the two outer loops operate without mutual interference, eliminating the need to extract the harmonic component of the load current and keeping computational burden low. The presence of an inner current loop enables current limiting during short-circuit faults, supporting low voltage ride-through capability. Frequency-domain analysis using closed-loop transfer functions obtained via AC sweep in PSIM software confirms loop decoupling, and hardware-in-the-loop experiments conducted on an OPAL-RT OP5700 platform validate effective harmonic compensation, improved DC voltage quality, correct power sharing between two distributed energy resources, and stable operation under load disturbances in an islanded DC microgrid.