A New Approach to the Protection of Industrial Drives

The approach to protection described here allows identification of several common fault conditions to be made using a single, and simply constructed sensor. In many of the fault conditions the technique also provides an automatic indication of fault severity. The system which has been developed is based on the sensing of the leakage magnetic field of the machines under test, and the subsequent analysis of such signals. Results are presented in which a low cost microprocessor based system is used to identify faults in both synchronous and induction machines. Indications as to how such systems may be used to protect groups of similar drives, rather than an individual machine, are also given.