CLOSED-LOOP CHARACTERISTICS OF VOLTAGE-MODE-CONTROLLED PWM BOOST DC-DC CONVERTER WITH AN INTEGRAL-LEAD CONTROLLER

A complete analysis of a voltage-mode-controlled pulse-width-modulated (PWM) boost DC-DC power converter is presented using a previously derived small-signal model for continuous conduction mode (CCM). All parasitic components such as the equivalent series resistance (ESR) of the filter capacitor, the ESR of the inductor, the transistor on-resistance, and the diode forward resistance and offset voltage are included in the model. A design procedure for an integral-lead controller including the loading effect of the voltage divider in the feedback loop is given. The Bode plots of the closed-loop control-to-output transfer function, input-to-output transfer function, input impedance, and output impedance are determined and illustrated for three values of the duty cycle. Step response plots of the PWM boost converter in the open-loop and closed-loop cases are shown for changes in line voltage and duty cycle.