A Novel Renewable Microgrid-enabled Metro Traction Power System - Concepts, Framework and Operation Strategy

This article presents a novel renewable microgrid-enabled metro traction power system (MMTPS), where the renewable energies and regenerative braking (RB) power of metro trains are unifiedly managed by renewable microgrids to reduce energy consumption and obtain the economic benefits for metro traction power system (MTPS). The concept and system framework of MMTPS is first established, where the metro energy router (MER) is presented as an innovative solution to efficiently integrate renewable microgrids into MTPS. Then, the four operation modes of MMTPS are defined and analyzed, including the voltage control mode, the power control mode, the RB supporting mode, and the islanded mode. Furthermore, the system average model of the proposed MMTPS is established to investigate the steady-state performances of MMTPS. In addition, the control strategies of MMTPS are developed to enable the different operation modes. Finally, the simulation and hardware-in-the-loop (HIL) experimental results are given to validate the effectiveness of the MMTPS. The proposed MMTPS as an innovative solution is able to reduce the energy consumption of MTPS and obtain economic benefits from renewable energy sources and RB energy.