Novel sliding valley current mode pulse train control for switching DC-DC converter

ABSTRACT

Multi valley current mode pulse train (MVC-PT) control technology can completely eliminate the low-frequency oscillation phenomenon of DC-DC switching converters operated in continuous conduction mode (CCM). However, this method needs to increase the number of preset value to broaden the output power range, which will increase the complexity and cost of the controller, and reduce the robustness of the system. Meanwhile, the output voltage ripple is uncontrollable and varied with the changes of the load. In this paper, a novel sliding valley current mode PT (SVC-PT) control technique is proposed to solve the above-mentioned problem. The SVC-PT operating principle and the deficiency of MVC-PT method are analysed in details. The approximate discrete-time models of SVC-PT and MVC-PT controlled switching DC-DC converters are constructed and compared. The comparison results verify that the proposed control method can thoroughly lessen the restriction of the controller on the output power range. Moreover, the control circuit is simplified and the output voltage ripple can be controlled. Finally, the simulation and experimental results are present to prove the feasibility and scientific of SVC-PT control technology.