A Robust Controller For DC-DC Switched Mode Power Converters

Power converters often consist of linear circuits that are switched between two configurations. Even though each of the configurations is linear, the overall behavior of the circuit is nonlinear. DC-DC switched mode power converters constitute simple but yet efficient means of DC power regulation [ 1,2]. The analysis and control of such a circuit is fairly complicated. Different methods have been employed for the modeling and control of DC-DC power converters [3-121. The state-space averaging (SSA) method is utilized for the analysis and control design of such circuits. This method assumes that the switching frequency is much higher than the bandwidth of the linear circuit configuration. In this paper, the SSA is adopted to describe the circuit by its space equations. An average value of the state over an entire switching cycle is first obtained. This is linearized around some nominal operating point to obtain a description of the circuit. A linear quadratic gaussian with loop transfer recovery (LQGLTR) controller is proposed. It guarantee the regulation of the output voltage to a nominal value in spite of parameter variation and duty cycle perturbations.