Tecnura (Jun 2016)
Buck DC DC converter using fuzzy logic control for no linear load
Abstract
Background: This paper presents a mathematical system called fuzzy logic as a control technique to improve the performance of a DC-DC converter (Buck) to changes in non-linear loads. Method: Through Simulink MATLAB was built a DC-DC converter of closed loop, which is placed in series with a controller based on fuzzy logic. The control inputs are the voltage signal and its derivative, and the output is a constant value, which tunes the duty cycle of a pulse modulator (PWM). This adjust the output of voltage of the controller according to a desired reference. The fuzzy controller was built with membership functions in which linguistic variables that explain when a value of output of voltage must be corrected and when the voltage variation is out of the established ranges between -1 and 1 percent of allowable variation were integrated. Results: To evaluate the performance of this type of control compared to a DC-DC converter with control of closed loop of unity gain, obtaining a 40% improvement in the integral of area regarding the fuzzy controller, with a stabilization time of 0.01s. In non-linear loads, there are random phenomena or own unwanted effects of resonance circuit, then was emulated by interrupting cycles of a time-controlled switch.
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