An Optimal Current-Sharing Control for Parallel Charging System with Supercapacitors Using Pseudospectral Method

The current-sharing is a critical issue for parallel charging system with supercapacitors, which is a high-order nonlinear system with control inputs constraints. In the paper, a uniform pseudospectral real-time closed-loop optimal control framework is proposed for constrained current-sharing control to minimize the charging time based on Radau Pseudospectral Method (RPM). In the framework, the current-sharing requirements are formulated as trajectory constraints utilizing the leader-follower structure with bounded inputs. The receding horizon control principle and pseudospetral observer are developed to construct a constrained closed-loop optimal control, in which RPM is leveraged to obtain real-time optimal solutions. Simulation results verify the effectiveness of the proposed approach.