MODELING AND SIMULATION ANALYSIS OF TRANSIENT BEHAVIOR IN BOOST CONVERTERS

This paper investigates the transient behavior of a Boost converter as it evolves toward steady state, a topic that is only briefly addressed in most university textbooks. State equations are established for the switch-closed and switch-open sub-processes based on Kirchhoff’s laws, together with a directional clamping constraint imposed by the diode. According to the discriminant of the second-order equation for the switch-open sub-process, the transient response is classified into underdamped, overdamped, and critically damped cases. On this basis, three operating scenarios are considered: permanently closed, permanently open, and periodic switching. MATLAB is then used to simulate the current and voltage waveforms, so as to reveal their internal connections and clarify the role of each sub-process in the overall evolution. The results show that, when the switch remains closed, the output voltage decays exponentially, whereas when the switch remains open, the output voltage is bounded above by the inputvoltage; in neither case can voltage boosting be achieved. Under periodic switching, the macroscopic trajectory is dominated by the damping type of the switch-open sub-process, exhibiting either an underdamped pattern of oscillation-clamping-stabilization or an overdamped pattern of rise-stabilization. At the microscopic level, switching-induced sawtooth-like ripples appear, while the boosting effect originates from energy storage during the switch-closed sub-process. Regardless of the damping type, the converter eventually converges to a steady state, and the final output voltage agrees with the prediction of classical steady-state theory.