Hierarchical Comprehensive Compensation Strategy for Multi-Voltage Level Traction Power Supply System

Power quality (PQ) problem and insufficient supply capacity have been challenges for long-distance traction power supply system (LD-TPSS). LD-TPSS based on high-voltage traction cables can enhance the power supply capacity. However, it triggers the end supply voltage overrun easily. In this paper, a new multi-voltage (MV-) TPSS is proposed, it can ensure the power supply capacity, regulate the voltage and realize the PQ management. Then, a comprehensive compensation strategy with a hierarchical structure is proposed. In the upper layer, voltage and PQ are managed in two stages to calculate the compensation power demand. The first stage, system voltage reactive power flow optimization is optimized. The second stage, unified management of PQ such as VU and power factor (PF) is completed. The control of each compensation device is realized by the lower controller. Finally, a detailed case comparison demonstrates the correctness and effectiveness of the system topology and strategy.