Integrated testing circuit for modular multi-level converter valve and control method of integrated testing circuit

The invention relates to an integrated testing circuit for a modular multi-level converter valve and a control method of the integrated testing circuit. The integrated testing circuit comprises a main circuit, a test valve and a control protection circuit, wherein the control protection circuit controls the main circuit and the test valve and performs test valve charging and on-load tests. The normal operation of the converter valve is detected and guaranteed, and when the converter valve is subjected to misoperation, an error prompt is provided through a voltage signal. Voltage-regulating, alternating current and direct current testing circuits of the converter valve are effectively integrated, and testing voltage and current adjustable converter valve charging and on-load tests are finished. The operating states of components in a positive and reverse charging circuit of the converter valve are comprehensively checked through alternating current charging, and the safety and reliability of follow-up tests are ensured. Moreover, high current is generated by utilizing reactive energy exchange, and the active loss of the testing circuits and the capacity of a testing input power supply are reduced.