Short-circuit and open-circuit faults monitoring of IGBTs in solid-state-transformers using collector-emitter voltage

Abstract

The aging and malfunction of devices with great power have been the main causes of the collapse and failure of grid systems. Since they are frequently used in grid systems, the failure of a solid-state-transformer has a great impact on the energy-saving and normal operation of network systems. Moreover, the main switching element of a solid-state-transformer is a welding type IGBT, which is also the most fragile part. First, the uneven current flow phenomenon of paralleled IGBT modules is introduced. Then, the main factors influencing solid-state-transformer failure, along with the short-circuit and open-circuit faults of IGBTs are analyzed. After the derivation $$V_\\text{CE}$$\n , it can be seen that it is related to the short-circuit and open-circuit faults of IGBTs. After comparison and analysis, one type of solid-state-transformer should be chosen to be widely applied and with integral functions for models and simulations. The IGBTs in solid-state-transformers vary in terms of fault condition and position, which influences the internal and external electrical parameters of systems. Therefore, it is proposed that collector-emitter voltage can be used to characterize the fault conditions of solid-state-transformers. Through simulation verification and waveform observations, it can be seen that the collector-emitter voltage and VM, which is the voltage of the primary side of the transformer in a solid-state-transformer, can be used to characterize the failure condition of the internal converter of the solid-state-transformer.