Analysis And Design Of The Control System Of Three-phase T-shaped Inverter With Reverse Blocking IGBTs

Multi-level inverters have distinct advantages over normal inverter in efficiency and high level voltage application. Multi-level inverters can output better voltage waveforms, ask for smaller voltage level of devices, produce less switch losses of devices. There are many choices for multi-level inverters topology, and each of them has its own advantages and disadvantages, so can be used in different occasions.This thesis is mainly about the design of three-phase T-shaped inverter with reverse blocking IGBTs. First, introduces the principle of this circuit and the actuality of reserves blocking IGBT (RB-IGBT).The T-shaped inverter with reverse blocking IGBTs'efficiency has been calculated. Compare it with NPC and T-shaped inverter with normal IGBTs with different switch frenzy and output power. Find out the suitable application occasion for T-shaped inverter with reverse blocking IGBTs.Furthermore, this thesis builds up the math model of this circuit, and chooses cascaded control for this inverter. Then, it gives out the design of current loop and voltage loop. This thesis analyzes and compares the effect to load regulation when a virtual resistance is added, or load current feed-forward control is added on the basis of the cascaded control. The analysis is verified by experimental results obtained from a prototype.A prototype of lOkW A-NPC three-phase three-level inverter with reverse blocking IGBTs is built. According to RB-IGBT switching characteristics, the structure and the working principle of the circuit, designs the drive circuit. The validity of the proposed design is verified by experimental results obtained from the prototype.