TESTING CIRCUIT, SYSTEM AND CONTROL METHOD FOR MULTIPLE SUBMODULES OF CASCADED CONVERTER

摘要

A testing circuit for multiple SMs of a cascaded converter and a control method thereof are provided. A current generator generates a testing current flowing into a testing module group. The testing module group includes two series-connected testing arms that each contains multiple SMs, or in an alternative way, the testing module group is composed of one or multiple testing units connected in series, and each testing unit includes two testing SMs connected in series reversely. The testing circuit the control method thereof realizes a mission profile emulation of the multiple SMs of the cascaded converter in both inverting and rectifying modes simultaneously to improve a test efficiency. A reverse series connection structure of the two testing SMs offsets a DC component in a capacitor voltage to reduce a power supply voltage required for a test. Dynamic and static control methods under different modulations for the test circuit are provided.