This chapter intends to present some applications of the fuzzy controllers to the automatic control of the DC-to-DC converters type boost, buck and buck-boost. For the mathematical modelling of these converters, one used averaged models; taking into account that controlled parameter is the average output voltage. One considered only the continuous conduction mode in the mathematical model. For each converter, one makes a short description of the principal scheme and the functioning mode and presents the averaged model. One obtains the transfer functions and finally builds fuzzy controllers in order to stabilize the output voltage with respect to the input voltage variations. The control is realized by modifying the duty cycle of the PWM command pulses. Obtained systems, both in closed loop and in open loop, are implemented in MATLAB/Simulink and simulations results are also presented.
Part of the book: Modern Fuzzy Control Systems and Its Applications
The current challenge in aviation is to reduce the impact on the environment by reducing fuel consumption and emissions, especially NOX. An open research direction to achieve these desideratums is the realization of new electric power sources based on nonpolluting fuels, a solution being constituted using fuel cells with H2. Reducing the impact on the environment is aimed at both onboard and aerodrome equipment. This paper proposes the simulation and analysis of an auxiliary power source APU based on a fuel cell. The auxiliary power source APU is a hybrid system based on a PEM-type fuel cell, a lithium-ion battery, and their associated converters. The paper presents theoretical models and numerical simulations for each component. The numerical simulation is performed in MATLAB/SimPower Sys. Particular attention is to the converter system that adapts the parameters of the energy sources to the requirements of the electricity consumers on board the MEA-type aircraft. Power management is performed by a controller based on fuzzy logic.
Part of the book: Aeronautics