Experimental and Numerical Exploration of Support Stiffness Influence on the Current Collection Quality of Pantograph and Overhead Conductor Rail System

Overhead conductor rail (OCR) is a power supply device in tunnel railways. This article aims to investigate the influence of train speed and support stiffness on the pantograph-OCR system (POCRs) dynamic behavior and propose improvement measures to the existing power feeding system to accommodate higher speeds. First, a field test is conducted to measure the equivalent stiffness of the supports currently utilized in the OCR system. The test results are adopted to modify the OCR model. Subsequently, a lumped mass model of the pantograph and the OCR model considering interlocking joints (ILJs) are developed. The analysis reveals that the contact force exhibits a nonlinear variation as the support stiffness increases, and good dynamic interaction can be achieved when support stiffness falls between $10<^>{4}$ and $10<^>{5}$ N/m. Then, time-frequency analysis explains the origin and amplification factors of multiple frequency components of the contact forces. The results show that structural wavelengths, such as span length (SS), half SS, and ILJ interval, are the primary sources of contact force components. Finally, the resonance mechanism of the POCRs is revealed, explaining the occurrence of deteriorated interaction performance under specific support stiffness.