This paper proposes a design for a renewable-energy hybrid power plant that is fed by a photovoltaic (PV) source with a supercapacitor (SC) storage device and is suitable for distributed generation applications. The PV array is used as the main generator, and the SC functions as an auxiliary source for supplying the (transient and steady-state) power deficiency of the PV array. For high-power applications, four-phase parallel boost converters and four-phase parallel bidirectional converters are implemented as a PV converter and a storage device, respectively. A reduced-order mathematical model of the PV and SC converters is described for the control of the power plant. Using a nonlinear approach based on the flatness property, we propose a simple solution to the dynamic, stabilization, and robustness problems in the hybrid power system. This is the key innovative contribution of this research paper. We analyze a prototype small-scale power plant composed of a 0.8-kW PV array and a 100-F SCmodule. The experimental results authenticate the excellent control algorithm during load cycles.