Real-time implementation of a fuzzy logic controller for DC-DC switching converters

This paper presents a successful implementation of a fuzzy logic controller structure for dc-dc switching converters and evaluates experimentally its sensitivity for variable supply voltages and load resistance variations. The optimum topology of the controller structure is determined using experimental tests. An advanced test bed system is used to evaluate the robustness capacities of the controller under varying loading conditions and input voltage variations. The experiment is performed using a low cost micro-controller PIC16F877 in order to verify the design performance over a wide range of operating conditions. Experimental results are obtained using appropriate scaling factors associated with the input variables of the fuzzy controller. The controller show very interesting tracking features and is able to cope with load changes and input voltage variations. The proposed controller structure is general and can be directly applied to any dc-dc converter topologies. The fuzzy controller structure is compared experimentally with the existing PI control used in industry. It yields a better dynamic performance without overshoot.