<p>A photovoltaic (PV)-based generator is a crucial component of modern electricity grids. Most PV systems utilize various maximum power point tracking (MPPT) algorithms to inject the maximum available power into the utility. However, on sunny days, consistently obtaining maximum power can lead to increased thermal stress and a reduced reliability of the power electronic-based DC-DC converter. This paper presents a thermal model for the DC-DC converter that evaluates the accumulated temperature based on power losses and ambient temperature sensed by the thermal sensor. A thermal control strategy is suggested to maintain the temperature of the converter's main components within allowable limits. The thermal control includes two stages: a primary stage that adjusts the switching frequency of the IGBT switches to decrease the accumulated temperature and a secondary stage that adjusts the current-based MPPT algorithm to reduce the maximum current through the main switch. This approach aims to extend the lifespan of the utilized DC-DC converter and lower its operational cost. Furthermore, the allowable range for switching frequency variation is determined through a stability analysis of the frequency response, which is evaluated using a Bode plot for the closed-loop system. The proposed thermal control was implemented in a MATLAB/Simulink environment. The associated results demonstrate the effectiveness of the proposed control in maintaining temperature within acceptable limits and thereby improving the reliability of the system.</p>

<p>In this paper, the output feedback tracking issue of induction motors is resolved by applying the sliding mode approach. We designed and implemented two robust sliding mode (SM) techniques to achieve high-performance control of induction motor drive; the second-order sliding mode (SOSM) approach using the twisting algorithm was compared with the classical sliding mode control. The method of decoupling electromagnetic torque and rotor flux for the induction motor was derived from the rotor field orientation control in the synchronous reference frame. The objective of the proposed methods is to control the rotor speed and the square of the rotor flux separately, in order to obtain robust control against disturbances and parametric uncertainties, and at the same time minimize the chattering phenomenon—the most significant drawback in the actual implementation of this technique. The stability of the proposed first-order sliding mode control was confirmed using Lyapunov stability theory. The availability and effectiveness of the proposed techniques were demonstrated through experimental results. The comparison between the results of the two proposed methods shows that the second-order sliding mode control using the twisting algorithm not only guarantees the same robustness and dynamic performances of traditional first-order sliding mode control but also achieves the reduction of the chattering phenomenon.</p>

<p>A current-sensorless PWM-based robust sliding mode controller is proposed for the DC-DC Boost Converter, a nonminimum phase system that presents major challenges in the design of stabilizing controllers. The development of the controller requires the measurement of the output voltage and the estimation of its derivative. An extended state observer is developed to estimate a lumped uncertainty that comprises the uncertain load and input voltage, the converter parasitics, and the component uncertainties, and also to estimate the derivative of the output voltage. A linear sliding surface is used to derive the controller that is simple in its design and yet exhibits excellent features in terms of robustness to external disturbances, parameter uncertainties, and parasitics, despite the absence of the inductor current feedback. Also, a simple procedure to select the controller gains is outlined. The robustness of the controller is validated by computer simulations.</p>