Handheld Low-Resistance Detection Device for EMU Electrical Circuits

With the rapid development of industrialization and the economy, high-speed rail technology has become a symbol of national strength. As the core equipment of modern railway transportation, the electrical system of Electric Multiple Units (EMUs) provides critical power support for normal train operation. While pursuing high operational efficiency for EMUs, ensuring their safety and reliability remains paramount. However, the EMU electrical system involves multiple electrical circuits with long and complex wiring, where loose electrical connectors during operation may lead to virtual contact phenomena. Therefore, research on identifying and diagnosing virtual contact in EMU electrical circuits holds significant practical value. By injecting a 5A current and applying the volt-ampere method to measure contact resistance, this method enables precise measurement of circuit resistance and establishes correlations between resistance values and virtual contacts, achieving accurate anomaly detection. Additionally, to ensure electrical circuit insulation integrity, this study incorporates insulation resistance measurements between lines. Detecting insulation resistance between lines effectively identifies potential leakage or insulation failures, further enhancing system safety and reliability.First, to address the complexity of EMU electrical circuits, a magnetic latching relay array connects multiple circuits to the detection device, forming a flexible multi-channel matrix test structure for efficient resistance measurement. Second, wireless communication and a human-machine interface (HMI) upload real-time data and test results to a centralized platform. Finally, a handheld circuit resistance detection device with low-resistance testing and automatic logic control functions has been successfully developed, providing robust technical support for EMU electrical system reliability assessment.