Optimum Boost Control of Quasi-Z Source Indirect Matrix Converter

Quasi-Z source indirect matrix converter (QZS-IMC) has been proved to have abilities of voltage boost, current filtering, variable voltage, and variable frequency. The voltage gain of QZS-IMC depends on QZS network shoot-through duty ratio <italic>D</italic>, rectifier modulation ratio <inline-formula><tex-math notation="LaTeX">$m_{i}$</tex-math> </inline-formula>, and inverter modulation ratio <inline-formula><tex-math notation="LaTeX">$m_{o}$</tex-math> </inline-formula>. Their multiple combinations are able to achieve the same voltage gain, but determining which is the optimal has not been addressed. In addition, the size of <italic>D</italic> is associated with the duration of shoot-through events of the QZS network, voltage and current stresses of power devices, and the system power losse. This paper proposes to find the optimal operation curve of <italic>D</italic> based on the constrained optimization theory. Simulation and experimental results validate theoretical analysis, the proposed optimal control, and the power loss reduction of the QZS-IMC.