On Modern IGBT Modules: Characterization, Reliability and Failure Mechanisms

Abstract

The increased demand of offshore power conversion systems is driven by newly initiated offshore projects for wind farms and oil production. Because of long distances to shore and inaccessibility of the equipment long repair times must be expected. At the same time the offshore environment is extremely harsh. Thus, high reliability is required for the converters and it is important to have good knowledge of the switching devices. This thesis investigates switching characteristics and losses of commercially available IGBT modules to be used for this application. It focuses on switching time and switching energy losses depending on gate resistance, current and voltage levels, operation temperatures, and show differences between several devices of the same type. Some test show how device characteristics and losses when the device has been exposed to stress over a certain period.