## 1 Introduction  
The increasing degree of pollution throughout the last decades made a change of direction in the policies of energy production, where renewables are preferred over the conventional ones. Actually, it an increment of 25% in the world energy consumption is expected for 2040, and the target is that clean ones can provide 40% of the whole production [1]. Researchers also forecast that solar PV panels could generate 15% of the global demand in 2050 [2]. Despite PV panels being highly dependent on sun irradiation (which fluctuates sufficiently depending on the geographical location), major advantages include the low maintenance and a large life-span service [3]. In several applications where a PV output voltage is unsuitable, DC-DC boost converters are used to step-up this variable, thus increasing the efficiency of the whole system. The voltage growth is carried out through a switching of electric circuits which indicates that the end-user voltage is dependent on a duty cycle [4]. The switching signal can be managed by a pulse-width-modulation (PWM) generator; this implies that a suitable control law can be designed with the target of maximizing the performance of the MPPT. Linear strategies can be a suitable first option for MPPT control. Despite the conventionality of proportional-integral-derivative (PID) controllers, they have been widely used in PV power systems. For instance, the author of [5] produced a linear simulation of a DC-DC converter with a PV panel; despite the controller being achieved through classic Bode analysis, the results reported a reduction of overshoot and settling time. Likewise, an advanced linear quadratic regulator (LQR) has been developed for boost-converters [6]; although the measurement of the performance of this algorithm needs experimental validation, the simulation outcomes revealed increments in robustness in comparison with similar strategies. However, linear controllers produce certain issues for real boost converters due to inconsistencies such as the intrinsic non-minimum phase [7]. Additionally, there are nonlinearities, such as solar energy, that depend on everyday weather; panels have assorted voltage-current oscillations and boost converters have a discontinuous action due to the switching [8; 9]. Nonlinear controllers are known not only for the performance improvement of boost converters but also for their practical implementation [10]. The P&O algorithm is a reliable nonlinear algorithm for MPPT that compares previous power measurements to current ones to find the MPP, using the duty cycle as a variable [11]. In the field of PV panels, this algorithm has even been studied in advanced and complex systems, such as PVs in space applications, as the authors of [12] explained in their research. The combination of this algorithm with a solar tracker provided suitable results. Due to its properties, it has also been used in assorted renewable systems such as wave energy generators [13], PV based microgrids [14], wind generators [15], and so forth. Despite its robustness and practicality, the downsides of P&O are related to the generated perturbations or partial shadow cases, which can produce, respectively, oscillations around the MPP or fall to a local maximum, which produces a reduction in accuracy [16; 17]. Another classic nonlinear structure is SMC, which not only enhances the dynamics of a system but also reduces the effects of disturbances and uncertainties [18]. For instance, [PERSON] et al. [19] proposed SMC for a boost-converter used in a fuel cell. The outcomes showed that one of the primary disadvantages of these structures is the chattering, which causes extra energy consumption. Even though the chattering can be reduced by using high order sliding modes--which have been implemented in the past [20]--it is impossible to eliminate this phenomenon since there are always unmodeled dynamics involved with control digitalization [21].