Modelling of double star induction motor for diagnosis purpose

The induction motor takes a large place in industry and we can find it in electrical ships. However, when high reliability is required, the control using the field-oriented method is often necessary and on-line diagnosis or off-line diagnosis have to be considered. The use of a double star induction motor or six-phase induction motor is slowly increasing and we find it in the high power process. Its main advantage lies in most reliability in case of a normal operating system. This paper describes a light model of a double star induction motor which, in spite of its simplicity, is able to provide useful indications for diagnostic purposes. Special attention is paid to the rotor defect. The most widespread way to make diagnosis is the analysis of the stator current spectrum. This method is classically named motor current signature analysis (MCSA). The responses obtained show the effectiveness of these kinds of ways.