Question

Problems: 1) A buck-boost converter is supplied from a source with an equivalent impedance. The converter can be considered ideal and represented as a transformer as seen in the circuit below. a) Calculate the duty cycle for maximum output voltage and the maximum output voltage. b) Plot the output voltage as a function of duty cycle to verify part a) 2.5 Ω , 20 V 75 Ω 1:M(D); Ideal Buck-Boost Converter Equivalent

Answer 1

For Maximum voltage (or) maximum power condition R_T = R_0 (1 - d/d)^r 2.5 = 7.5 (1 - d/d)^r here R_T = input impedance = 2.5 omega R_0 = output impedance = 75 omega 0.1825 d = 1 - d 1.1825 d = 1 d = 0.8456 rightarrow required duty ratio (b) plot V_0 diagonaldownwardleftarrow = V_T diagonaldownwardrightarrow = (d/1 - d) using MATLAB plot this closely observe in between 0.8 to 0.9 the output voltage turns toward maximum and in out finding too we got 0.86 as duty ratio to max out the voltage

closely observe in between 0.8 to 0.9 the output voltage turns toward maximum and in out finding too we got 0.86 as duty ratio to max out the voltage .