Analysis, Design, and Implementation of Passivity-Based Control for Multilevel Railway Power Conditioner

In recent years, railway power conditioner (RPC) has been used to improve the power quality of a traction power system. In engineering application of RPC, mismatches between parameters used in controller and actual values are inevitable, which will increase the difficulty of current controller design and deteriorate compensation performance. In this paper, a passivity-based control (PBC) system is studied for multilevel RPC to enhance its tolerance for mismatches. According to the topology of multilevel RPC, equivalent electrical and mathematical models are developed. To employ PBC, Euler–Lagrange system model of RPC is established by Park (
αβ/dq
) transformation, and the passivity of RPC and stability of PBC are proved. On this basis, the robustness of PBC is analyzed and criteria for damping selection are derived. Finally, simulation and experiments have been carried out to verify the structure and control method in the paper.