Reactive Power Compensation and Negative-Sequence Current Suppression System for Electrical Railways With YNvd-Connected Balance Transformer—Part II: Implementation and Verification

This part mainly focuses on the implementation and verification of the reactive power compensation and negative-sequence current suppression system with YNvd-connected balance transformer, by means of simulation and experiment. The system model is presented, and a current control method, which explores the dissipation characteristic of the proposed system under two-phase rotating frame, is analyzed. Then, a stability analysis of this control is made, considering the deviations of system parameters and the time delay caused by the low-pass filter. Besides, dc-link overall control and balance control are investigated, and the self-balance ability of multiple dc links is briefly discussed. Both the simulation and experimental results verify the effectiveness of the proposed system topology, compensation strategy, and control method.