Current Collector Health Monitoring of LRT Trains Powered by Three-Phase AC Power Rail Based on Inductive Coupling Method

The current collector is a key component of most light rail transit (LRT) trains. It draws electric power from the catenary or the power rail for each moving train. Due to wear, tear, and harsh operating environments, the current collector will malfunction, which can lead to unexpected power interruptions for the train and directly affect service reliability. This article presents an inductive coupling method for current collector health monitoring of LRT trains powered by the three-phase ac power rail. The monitoring system developed using the proposed method can be easily fitted on a train so that it doubles up as a train-borne health monitoring system (TBHMS) during revenue hours. The TBHMS monitors the electrical contact quality (ECQ) between the current collector shoe (CCS) and the power rail in a noncontact and safe manner. By doing so, it eliminates the need of inspection during engineering hours, which is both labor-intensive and time-consuming. The current collector of such trains comprises a current collector assembly that holds the CCSs. Two performance indexes, the contact quality index and the contact loss index, are defined to quantify the health conditions of CCS and CCA, respectively.