1. State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, China
2. National Rail Transit Electrification and Automation Engineering Technique Research Center, Southwest Jiaotong University, Chengdu 610031, China
3. China Railway Eryuan Engineering Group Co., Ltd., Chengdu 610031, China
4. Department of Built Environment, Oslo Metropolitan University, 7491 Oslo, Norway