A Peak Capacitor Current Pulse Train Controlled Buck Converter With Fast Transient Response and a Wide Load Range
It is known that the ripple based control of a switching dc dc converter benefits from a faster transient response than a conventional pulse width modulation (PWM) control switching dc dc converter. However, ripple based control switching dc dc converters may suffer from fast scale oscillation. In order to achieve fast transient response and ensure the stable operation of a switching dc dc converter over a wide load range, based on a conventional pulse train (PT) control technique, a peak capacitor current PT (PCC PT) control technique is proposed in this paper. With a buck converter as an example, the operating modes, steady state performance, and transient respond performance of a PCC PT controlled buck converter are presented and assessed. To eliminate fast scale oscillation, circuit and control parameter design considerations are given. An accurate discrete iteration model of a PCC PT controlled buck converter is established, based on which the effects of circuit parameters on the stability of the converter operating in a discontinuous current mode (DCM) mixed DCM continuous conduction mode (CCM) and CCM are studied. Simulation and experimental results are presented to verify the analysis results.
IEEE Transactions on Industrial Electronics