Current-Limiting DC/DC Power Converters

A new nonlinear control framework that guarantees the desired regulation (voltage, current, or power) with an inherent current-limiting capability for different types of dc/dc power converters is presented in this brief. This framework is based on the idea of applying a virtual resistance in series with the inductor of the converter, which changes according to nonlinear dynamics that depend on the control task. Without requiring any knowledge of the converter inductance, capacitance, or the load, the controller structure is appropriately formulated for each power electronic system based on the nonlinear model of the converter. Using input-to-state stability theory, it is proven that the inductor current remains below a maximum value at all times, even during transients, independently of load and input voltage variations. This offers an inherent current-limiting property of the converter under faults, input voltage sags, and unrealistic power demands without the need of external protection mechanisms, saturation units, or current limiters. Extensive simulation and experimental results validate the effectiveness of the proposed control scheme and its current-limiting property, with comparison to traditional control strategies.