A Method for Measuring the Blocking Capacity of IGBT Modules Used in Marine Environments

Currently, insulated gate bipolar transistor (IGBT) modules are developing rapidly and have been used to operate in many different environments. However, when IGBT modules are used in marine environments, there is high humidity and salt spray in the environment. These environmental causes will result in the formation of conductive paths between the different interfaces (internal and external) of the IGBT module. Under the influence of high humidity and salt spray in the marine environment, the conductive path greatly reduces the blocking capability of the IGBT module and severely disrupts the IGBT module’s stable operation. To address this issue, this paper simulates marine environment experiments on IGBT modules by salt spray and high voltage, high humidity, high temperature, and reverse bias (HV-H3TRB) experiments. It turns out that after treatment in the marine environment, conductive channels are formed both inside and outside the IGBT module. This is equivalent to connecting a resistance in parallel outside the IGBT module. It makes blocking capacity decrease significantly. Therefore, this paper establishes a nonlinear relationship between the blocking resistance and voltage of the IGBT module. It can measure the faulty resistance of the conductive paths of the IGBT modules. In practice, the blocking capability can be determined by measuring the leakage current of the IGBT modules through the relationship between the faulty resistance and the leakage current of the device. This can provide an important reference for the stable operation of IGBT modules in marine environments.