A New Control Law Based on the Differential Flatness Principle for Multiphase Interleaved DC-DC Converter

This brief presents an innovative control law for a distributed dc generation supplied by a dc power source, here, a fuel cell (FC) generator. Basically, an FC is always connected with a power-electronic converter. This kind of system is a nonlinear behavior. Classically, to control the voltage, the current, or the power in the converter, a linearized technique is often used to study the stability and to select the controller parameters of the nonlinear converter. In this brief, a nonlinear-control algorithm based on the flatness property of the system is proposed. Flatness provides a convenient framework for meeting a number of performance specifications on the power converter. Utilizing the flatness property, we propose simple solutions to the system performance and stabilization problems. Design controller parameters are autonomous of the operating point. To validate the proposed method, a prototype FC power converter (1.2-kW four-phase boost converters in parallel) is realized in the laboratory. The proposed control law based on the flatness property is implemented by digital estimation in a dSPACE 1104 controller card. Experimental results with a polymer electrolyte membrane FC of 1200 W and 46 A in the laboratory corroborate the excellent control scheme.