Is the T-type three-level drive circuit the same as the I-type drive?

units in series? You mean chain structure, three phases are independent, (transformer isolated chain, H-bridge chain). There are also many kinds of three levels, such as traditional diode-clamped, flying-across and T-type architecture. The types of three levels are different, and the differences are different. ● Chain STATCOM structure, the DC side is separated, and the capacitor voltage fluctuates greatly, so the capacitor with large capacity should be considered. ● The capacity of the chain structure capacitor is about twice that of the DC side capacitor. ● Design mode of chain structure: Triangle connection and Y connection can be adopted, and the corresponding parameters and insulation design are different. Y-connection bears the phase voltage of power grid. Triangle connection bears the line voltage of power grid, which has advantages in compensating negative sequence current. ● Compared with "diode-clamped three-level": each phase topology has two fewer clamping diodes, and the corresponding conduction loss is reduced; The correspond installation space is reduced. ● When the control time is different, the "diode-clamped three-level" needs to turn off the outer tube first, and then turn off the inner tube to prevent the bus voltage from being added to the outer tube and causing damage. There is no timing requirement for T-type. ● Each device bears 1/2 bus voltage compared with "diode-clamped three-level"; T-type Sa1 and Sa2 need to bear all bus voltages, which leads to the increase of the volume of the heat sink and the relative cost. ● * * * collector and * * * emitter, the principle is the same. I can only give you these for reference. You don't even know what kind of architecture, and the comparison is not targeted.