This paper presents the general dynamic descriptions of current-fed converters applied in the solar or photovoltaic applications including an impedance-based method to assess the stability of the corresponding interconnected system. Several earlier unknown general parameters are indentified governing either the low-frequency behavior of the closed-loop converter or affecting the source or load interactions. Experimental evidence is provided to support the theoretical findings based on current-fed superbuck and boost converters both in time and frequency domains.