Search

It is shown that an incorrect parameter limit in the existing Pspice pulsewidth modulated (PWM) switch model has been detected. The main objective of this work is to alert users of such models to a potential source of simulation error under certain parameter specifications as shown here. Simulation of the boost converter operating in discontinuous conduction mode (DCM) based on the incorrect model results in either convergence problems or wrong results. Correction of the model is provided and its validity is verified using a specific converter example. The results illustrate how the old and corrected models produce different results when the boost converter is subjected to some transients under sudden load variations.

A switched-capacitor-based (SC) step-up DC converter is proposed. It contains no inductors and transformers, thus it can be realized in small size, exhibiting low weight and high power density. Two switched-capacitor circuits, operating in antiphase in each half-cycle, are used to control the energy flow from an unregulated voltage source to a regulated output. The capacitors are charged and discharged according to a designed sequence. To enhance the line and load regulation capability, in each half-cycle, each charging interval is split into two subintervals, which are followed by noncharging subintervals whose duration is dictated by the pulsewidth modulation (PWM) feedback circuit. The new converter is advantageous for applications in which significant line drops are likely to occur.