S. Haghighatnia, H. Toossian Shandiz,
Volume 15, Issue 2 (6-2019)
Abstract
A novel nonlinear fractional order sliding mode controller is proposed to control the chaotic atomic force microscope system in presence of uncertainties and disturbances. In the design of the suggested fractional order controller, conformable fractional order derivative is applied. The stability of the scheme is proved by means of the Lyapunov theory based on conformable fractional order derivative. The simulation results show the advantages of the designed controller such as fast convergence speed, high accuracy and robustness against uncertainties and disturbances.
G. Hamza, M. Sofiane, H. Benbouhenni, N. Bizon,
Volume 19, Issue 2 (6-2023)
Abstract
In this paper, a wind power system based on a doubly-fed induction generator (DFIG) is modeled and simulated. To guarantee high-performance control of the powers injected into the grid by the wind turbine, five intelligent super-twisting sliding mode controllers (STSMC) are used to eliminate the active power and current ripples of the DFIG. The STSMC controller is a high-order sliding mode controller which offers high robustness compared to the traditional sliding mode controller. In addition, it reduces the phenomenon of chattering due to the discontinuous component of the SMC technique. However, the simplicity, ease of execution, durability, and ease of adjusting response are among the most important features of this control compared to some other types. To increase the robustness and improve the response of STSMC, particle swarm optimization method is used for this purpose, where this algorithm is used for parameter calculation. The simulation results obtained using MATLAB software confirm the characteristics of the designed strategy in reducing chattering and ensuring good power control of the DFIG-based wind power.
Somayeh Rajabi, Hadi Chahkandi Nejad, Majid Reza Naseh,
Volume 21, Issue 1 (3-2025)
Abstract
In this paper, a Lyapunov-based adaptive 2nd-order sliding mode controller is proposed to control the current in an active power filter (APF). The penetration of APFs has been exponentially increased because of their high flexibility and fewer resonance problems. Moreover, they can compensate high range of current harmonics and reactive power. The voltage and current control loops have always been interesting areas for researchers since the satisfactory performance of the APF is highly dependent on these control loops. A sliding mode controller (SMC) is a mighty controller when uncertain conditions are considered. However, in order to reduce the chattering- high-frequency switching- and improve the steady state operation, stability, and robustness of the controller, it is usually decided to adaptively tune the gains of the controller. In this paper, a simple-structure adaptive SMC (ASMC) is proposed which can be implemented easily. This ASMC is shown to be stable using the Lyapunov theorem and proved with SIMULINK simulation that it has less steady state error, less chattering, and faster dynamic response compared to the conventional SMC.
