| Abstract |
This paper describes a Fuzzy Logic Controller for the output voltage of a single phase ac/dc Buck-Boost converters. The use of these rectifiers with a suitable PWM current controller, ensure a near unity power factor operation and input current with low harmonic content. The reference of the current controller is a sinusoidal waveform whose amplitude is modulated by the external voltage controller. Usually, the well-known Proportional Integral (PI- Controller is used for the voltage controller. However, the relationship between the amplitude of the input current and the output voltage is non-linear and depends on the load. Therefore, the PI-parameters are not constant. To correct this problem, a fuzzy logic controller is derived. Simulation results are presented, and the performances of the Fuzzy Logic Controller are compared with the behavior of the widely used Proportional Integral (PI) output voltage control, aided by a inner loop for the PWM current mode modulator. |
