Fault detection and isolation with hybrid bond graphs in a direct current drive

The full bridge inverter is one of the power electronics converters that are widely used in a lot of systems such as electrical machines. In particular, this paper takes the separately excited DC motor as the case of study. It is known that this unified system can present failures due to the frequencies and voltages higher than the rated ones in the electronic switches, bad lubrication to the bearing, etc. Failures in this kind of systems could origin environmental problems, unhealthy people and/or damages in facilities and equipment. To this situation, it is important to apply a fault detection and isolation system in the fault transient stage. This paper shows the design and simulation results of the application of a hybrid bond graph diagnostic system to our case of study. This diagnostic system, which is a quantitative approach, is well suited for power converters and electro-mechanical systems, because it gives the possibility of obtaining diagnostic properties. The results of the investigation are presented by means of simulations and they show that all of the faulty devices considered can be detected and isolated.