Non-invasive Flexible Current Probe as A Diagnosis Tool Inside a PWM Chopper module

Traditional non-contact rigid probes fail to meet the time-domain reconstruction requirements inside industrial modules in an enclosed chamber. In this paper, a flexible current probe is proposed as a diagnosis tool to extend the non-invasive time-varying current reconstruction technology inside an industrial PWM-chopper module in an enclosed chamber. The flexibility of the probe allows for direct placement on trace surfaces or attachment to trace sides for current measurement without intrusion. Reflection coefficient curves obtained at typical bending angles demonstrate remarkable consistency with an average error of 0.63%. Furthermore, time-domain curves of reconstructed currents closelymatch directly measured currents with an average error below 0.24%. The flexible probe demonstrates consistent and stable performance across different bending levels in non-invasive current measurement tests. In the application tests, the experimental results validate its utility as a diagnostic tool for non-invasive time-varying current detectionwithin an industrial PWM-chopper module, achieving an average error below 0.11%. Additionally, the proposed probe enables detection of varying output currents for load failure analysis in constant voltage output modules.