Control and implementation of a multilevel matrix converter

The multilevel matrix converter was proposed as a new approach to the power electronics of variable-speed wind turbine applications. The converter was designed to increase the energy capture of wind turbine systems by improving the converter efficiency under low wind speed condition, where typical wind turbine systems operate most of the time, without sacrificing the performance at the rated condition. Multilevel modular approach employed in the multilevel matrix converter is scalable to higher power and higher voltage levels, allows the use of superior low-voltage fast-switching semiconductor devices in high-voltage high-power applications. Besides, it can also maintain high efficiency at partial of its rated power.; This thesis focuses on the development of practical real time control schemes for the multilevel matrix converter. The control schemes for the multilevel matrix converter consist of two tasks that must be performed simultaneously. First, they must control the switch modules to synthesize terminal voltages. Second, they must regulate capacitor voltages in the switch modules. The well-known space vector control technique was adapted as an approach to synthesize terminal ac waveforms. This approach is well suited to implementation using modern digital hardware, and it allows additional control schemes to be integrated easily. The single-capacitor control scheme was proposed as a way to determine a single capacitor used in each switching period for synthesizing terminal voltages such that the capacitor charge balance can be achieved. A capacitor voltage balancing control, which was proposed to regulate the internal capacitor voltages of all nine switch modules, was also developed and experimentally demonstrated. The control is based on a modification of the space vector modulation. Lypuanov theory was used to guarantee the stability of the proposed control scheme.; The first-working laboratory prototype of multilevel matrix converter was implemented to demonstrate the operation of the converter and to verify the proposed control schemes. The prototype shows the feasibility to control a complex converter containing many modules using modern digital hardware.