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In this paper, a novel adaptive second-order sliding mode (2-SM) control approach, based on online zero-crossing detection, was proposed to solve the problems of the chattering and fixed control gain for buck converters with multi-disturbances. In modeling, the possible parameter perturbations and external disturbances of the converter system were contained. Instead of the traditional first-order sliding mode (1-SM), the twisting algorithm with 2-SM was adopted for the controller design, which could overcome the chattering problem and realize control continuity. Meanwhile, a novel adaptive mechanism was introduced to replace the conventional fixed control gain by time-varying control gain, the idea of which is to calculate the number of the zero-crossing points of the sliding surface online. As a result, the control magnitude of the improved controller could be reduced to a minimal admissible level, and the steady error of the output voltage could converge to the expected value. Furthermore, the robust stability of the converter system with multi-disturbances wads investigated. Comparative simulations and experiments validated the advantages of this paper as offering better robustness and control performance. [ABSTRACT FROM AUTHOR]

This paper presents a solution based on optimal PID coefficients including anti-wind up for buck converter presents using meta-heuristic algorithm and chaos theory. A hybrid algorithm is called chaotic based flower pollination algorithm is provided by combining flower pollination algorithm and chaos theory with different maps. Five different choatic maps are used in the aim of increasing the efficacy and efficiency of flower pollination algorithm. In order to adjust the parameters combined in the flower pollination algorithm, random number sequences from Henon, Logistic, Sine, Tent and Tinkerbell chaotic maps are used. The success of the developed algorithm is evaluated by solving 23 different benchmark problems which are very common in the literature. The results of comparative experiments show that henon chaotic map based flower pollination algorithm is sufficiently effective in solving these benchmark problems. Thus desinging optimal PID with anti-windup for buck converter, henon chaotic map based flower pollination algorithm is used. Also henon chaotic map based flower pollination algorithm has better performance than firelfy algorithm and whale optimization algorithm existing in literature. [ABSTRACT FROM AUTHOR]