In this paper, we consider the application of the piezoelectric energy collection using a portal structure of two-degrees-of-freedom. The piezoelectric material is considered as a linear device using a capacitive mathematical model. The portal structure is of two-degrees-of-freedom, considering a quadratic coupling between the first and second modes of vibration. 2:1 internal resonance between the first and second modes is set, which is a special condition of this type of system due to the appearance of a saturation phenomenon. As this phenomenon causes the system to start vibrating from the second mode and, in a steady state, vibrates to the first mode, the objective of this work is to verify the energy uptake, considering the different positioning of a piezoelectric material, which is coupled to the supported beam or to the column. In addition, the structure is excited by a non-ideal DC motor with limited power supply. The results show a considerably nonlinear behavior due to the non-ideal motor and, with the saturation phenomenon, it is more efficient to collect energy by coupling the PZT to the column. The stability of the system due to the piezoelectric coefficient T is also accounted for analysis, as it is related to the coupling of the structure. The stability analyzes are carried out by numerical tools as phase planes, Poincare maps bifurcation diagrams, 0-1 test.