Broken Bar Fault Detection based on Set Membership Identification for Three Phase Induction Motors

Abstract: This article presents a fault detection scheme for the case of a broken bar occurrence in a three phase induction motor. The proposed scheme relies on Set Membership Identification (SMI) and novel proposed boundary violation rules for the identified motor’s parameters. The model of the three phase induction motor is being transformed into an equivalent two phase model, described in the q− d space, for both the normal and the faulty case. By the utilization of the SMI technique, the simplified equivalent model of the induction motor is being identified during the steady state operation (non–fault case), while at the same time safety bounds for the identified variables are being provided, based on an a priori defined corrupting additive noise. On the event of a fault, specific fault detection conditions are being proposed that can capture the specific type of a broken bar fault. The proposed conditions depend on: a) abnormal parameter jumps, and b) rapid changes in the volume of the bounding uncertainty, which is being formulated either by ellipsoids or orthotopes. Detailed analysis of the proposed approach as also extended simulation results are being presented that prove the efficiency of the proposed scheme.