A Unified Analysis of PWM Converters in Discontinuous Modes
نویسنده
چکیده
Three discontinuous operating modes of PWM converters are considered in this paper-the discontinuous inductor current mode (DICM), the discontinuous capacitor voltage mode (DCVM) and a previously unidentified mode named discontinuous quasi-resonant mode (DQRM). DC and smallsignal ac analyses are applicable to all basic PWM converter topologies. Any particular topology is taken into account via its well-known dc conversion ratio in the continuous conduction mode. The small-signal model is of the same order as the statespace averaged model for the continuous mode, and it offers improved predictions of the low-frequency dynamics of PWM converters in the discontinuous modes. It is shown that converters in discontinuous modes exhibit lossless damping similar to the effect of the current-mode programming.
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