Fuzzy controller for dynamic performance improvement of a half-bridge isolated DC-DC converter

Due to the switching property included in their structure, half-bridge power electronic DC-DC converters have a nonlinear behavior and their controller design is accompanied with complexities. The use of small signal model of the converter in conjunction with artificial intelligence in a robust controller structure guarantees excellent dynamic response. This work implements the fuzzy controller for converter circuit to improve the dynamic performance of asymmetric half-bridge DC-DC converter. It establishes fuzzy controller to overcome the limitations of the conventional PI controller. The conventional controller has lower loop band width and high distortion coefficient. So the system response is sluggish. In this work fuzzy logic is used to improve the characteristics of the DC-DC converter system by controlling its duty cycle. The fuzzy controller output is compared with a PI controller for five different operating conditions. The results show that the fuzzy controller is able to achieve faster transient response, less peak overshoot, better rejection of disturbances and is less dependent on the operating point of the converter. (C) 2014 Elsevier B.V. All rights reserved.