| Popis: |
This work presents the implementation of an adaptive pulse skipping modulation-based quadratic buck converter. The voltage gain of quadratic buck converter is quadratic in nature and depends on the square of the duty cycle, unlike a standard buck converter whose voltage gain is proportional to the duty cycle. It has a steep step-down voltage conversion ratio capability. The converter efficiency is affected by conduction and switching losses. The conduction losses are load-dependent; it is low at light load. Nevertheless, switching losses dominates if conventional control technique like Pulse Width Modulation is adopted. The Switching losses can be reduced by Pulse Skipping Modulation (PSM), in which a few pulses are skipped. The PSM technique warrants efficiency improvement under light load, where the load current is low and the inductor has discontinuous conduction. The existing Pulse skipping modulation controller uses PWM as a building block, and in other techniques, it needs to pre-specify the number of charge pulses and skip pulses for the load current. The controller of the proposed adaptive PSM for quadratic buck converter generates pulses autogenously. This scheme gives better voltage regulation and provides stable periodic behavior. The stability is examined using a state-space model, and efficiency and mode transition have been observed using simulation results in MATLAB with Simulink modelling. |
