Portable acquisition and identification tool for induction machine diagnosis

A new parameters identification method for induction machine electrical faults detection is presented in this paper. Typical evolving faults like: phase resistance increase caused by poor contacts; turn-to-turn short-circuits; unbalanced supply voltages; magnetic circuit ageing; and squirrel-cage bar rupture, are taken into consideration. A triphase abc frame it was taken into consideration for real phase parameters identification. In order to provide the electrical parameters, an identification technique based on currents, voltages and speed acquisition during transients (e.g. starting-up) has been developed on a portable acquisition and post-processing system. The proposed equipment includes a 486 notebook with PCMCIA acquisition board, current clampmeters, voltages probes and signal conditioning module and can be applied to any drive without interfering with operating conditions. Also, a database software processor was developed for storing and comparison against the reference set of each new parameter set identification, enabling a time evolution behaviour evaluation. The system can be successfully applied to both periodical preventive maintenance and the electrical parameters verification of repaired induction machines