Semi-converter fault diagnosis in DC motor drives, by Park´s vector approach

Presents an approach, based on computer-aided monitoring of the three-phase supply current Park´s vector, for diagnosing semi-converter faults in DC motor drives. The online diagnosis is based on identifying unique signature patterns in the figures obtained. For single-phase AC supply the observed figures are straight line segments, whose direction is associated to the opened phase. Power switches faults, either an open-circuit or a short-circuit, are generally characterized by distinctive patterns of the three-phase supply current Park´s vector representation, whose angular orientation is associated to the faulty power switch. Both simulation and laboratory tests results are shown to be in relatively good agreement. A systematic procedure suitable for a complete diagnostic, i.e. detect the fault, identify its type and locate the faulty component, is therefore obtained.