Investigating Failure Mechanisms in DC Hybrid Switchgear Through a Methodical Evaluation of Critical Faults

Abstract

For safe and reliable DC Distribution systems, appropriate switchgear are key elements. Hybrid switchgear technology has the potential to satisfy the requirements of these prospective DC systems. This paper contributes to the improvement the design of these switchgear by providing information on increasing the reliability and safety of hybrid switchgear as a basis for the design and development process. This is achieved by a proprietary failure analysis method based on an FMEA. The developed methodology is presented and applied to a generic parallel structure of a hybrid DC switchgear as an example. A total of more than 60 failure modes are identified and evaluated. The formation of the most critical faults in three of the functional groups are investigated experimentally. One key aspect is the reproducibility of fault formation. With this, the previous theoretical considerations are verified. Furthermore, the effects, detection approaches and possible mitigation measures of these failure modes are provided.