Analysis of Brushed DC Machinery Faults With Coupled Finite Element Method and Equivalent Circuit Model

Although brush type DC machinery has lost market share over the years to its brushless counterparts, it still maintains a significant presence in the automotive, aerospace, power tool, and home appliance industries. Especially in automotive and aerospace power system applications, early detection of brush type DC machine faults will help to avoid problematic system failures, decrease maintenance costs, and increase system reliability. This paper focuses on a modeling approach that is used to investigate the effects of various fault mechanisms of the brushed DC machine at an early stage in their progression. Results from the proposed model are then used to show the effects of a variety of DC machine failure modes and identify observable parameters to assist in early fault detection. The simulation results are then confirmed through laboratory experiments performed on a DC generator.