AC-DC-AC Matrix Converter And Direct Torque Control

AC-DC-AC matrix converter is a new kind of "all silicon" power converter. Its structure of topology is type of AC-DC-AC, has DC-bus between input rectifier and output inverter, without large reactive energy storage components. Its performance of input and output is same as AC-AC matrix converter, with sinusoidal currents of input and output, the power factor of input can be reached 0.99 and more, furthermore, it is adjustable. The energy can be bi-directional flew.The structure of topology of AC-DC-AC matrix converter is flexible, the three to three phase 18 switches AC-DC-AC matrix converter is most researched now, is also main objective in this dissertation.First, from the change of the topology of AC-DC-AC matrix converter, the characteristics of several topologies is studied, a commutation scheme of DC zero current is proposed, as well PWM rectify of unit power factor and space vector modulation scheme of inverter. Based on the frame character of AC-DC-AC matrix converter, it is applied on multi-drive speed adjustable system, combined with commutation scheme of DC zero current; a control scheme on multi-drive is proposed. Second, AC-DC-AC matrix converter based the direct torque control (DTC) has its character, approximate circle flux DTC and hexagon flux DTC are presented based on AC-DC-AC matrix converter, their simulation models are built. In this dissertation, the technique of realization of main circuit and digital control system are researched, a hardware experiment platform is built with DSP2812 evaluation board being control center. In this dissertation, the software is designed by assemble language, the key technology of resolving phase floating in PWM rectifier control and realizing synchronous control between rectifier and inverter are proposed and testified.The dissertation mainly pays attention on the schemes of control and commutation, the application of AC-DC-AC matrix converter on the multi-drive speed adjustable system, and the application on DTC system. And some valuable experience and results were got and testified, and contributed to the AC-DC-AC matrix converter's industry application.