Özet:

When the power electronic converters in the DC microgrid structure are connected in a cascade structure, they may exhibit constant power load (CPL) behavior. CPL’s negative incremental impedance causes an unstable influence on in DC microgrid. However, by employing various control strategies, these systems may be made stable. When compared to traditional control methods, sliding-mode control, which is a non-linear control approach, provides a more robust response to external disturbances. In this paper, the performance of a conventional sliding-mode controller for a DC/DC buck converter feeding a CPL is improved using the super twisting algorithm. The super twisting method, which is a second-order sliding mode control algorithm, is a technique used to decrease the chattering effect of the sliding mode controller. In the proposed method, the switching rule of the conventional sliding mode control has been changed by adding super twisting control law. The proposed controller guarantees system stability during steady-state and ensures that the output voltage stays constant whether the input voltage or constant load power changes. Also, the proposed controller greatly decreased the chattering effect, which is the most major drawback of sliding mode control. The performance of the proposed controller was verified by both simulations in the MATLAB/Simulink and experimental studies. Moreover, the superiority of the proposed controller was offered by comparing it with the conventional sliding mode control.

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