Research on the onboard auto-test system for track circuit compensating capacitors

Abstract

A kind of onboard auto-test system was proposed so as to detect the track circuit compensating capacitors in real time. The system model and design were based on the resonance current detection method. The data acquisition card generated the actuating sine signal first, which was amplified and coupled onto the rail. Two wheels of the test vehicle, rail lines between and the capacitor connected between the rails formed a closed LC loop. If the actuating signal frequency coincides with the inherent resonance frequency of the loop, a reactive current will be produced within the loop. After the current is sampled and further processed, the capacitor value can be estimated. The system principle and architecture are described in detail. Experiments show the invalid capacitors can be efficiently detected and located in real time.