Operation testing device for voltage source type converter sub-module and testing method thereof

The invention relates to an operation testing device for a voltage source type converter sub-module and an operation testing method thereof. A sub-module operation testing device comprises a charging power supply E, an auxiliary switch K, an auxiliary module, a sample module and a load electric reactor L, wherein the two ends of the auxiliary switch K are respectively connected with the charging power supply E and the auxiliary module; the two ends of the load electric reactor L are respectively connected with the auxiliary module and the sample module; and a capacitor Cs1 of the charging power supply E and a lower bridge arm V3 of the auxiliary module as well as a capacitor Cs2 of the charging power supply E and a lower bridge arm V4 of the sample module are grounded. According to the scheme, voltage, current and thermal stress of the sub-module under an actual working condition can be equivalent to one another so as to provide a brand new technical means for a test of a third-generation voltage source converter (VSC) sub-module and a brand new path for practical application.