Design of power drive dedicated to the investigation of faults

The paper presents the development of a test bench for the investigation of faults in a power drive. Firstly, the presentation is made for different components in an induction machine drive. Secondly, since the machine parameters are controlled by PWM signals via IGBT converter, a PWM generator is built in order to control the machine and create different types of faults related to the drive of the converter. Subsequently, simulation and experiment are carried out for two typical faults of the converter: intermittent gate-misfiring fault and open-circuit fault. Finally, since the machine speed is usually required for the calculation of characteristic frequencies of most faults in the induction machine, it is estimated on the basis of the slot frequency component in the spectral of stator current and total input power. The obtained results are the evidence to show that the test bench is appropriately usable for the investigation of not only the normal operation but efficiently for the fault exploration.