Three-Level Indirect Matrix Converter With Series Z-source Networks

The concept of series Z-source network has been extended to a conventional indirect matrix converter in previous publications for raising the voltage gain to unity and beyond. In this paper, this idea is adapted and applied to a three-level indirect matrix converter. Two series Z-source networks are placed on the virtual dc-link between the rectifier and the neutral point clamped inverter on the positive and negative dc rails. Upper and lower shoot-through states are used for voltage boosting. The series Z-source capacitor voltages and starting current stresses are reduced. A virtual space vector PWM method has been developed to ensure voltage boost ability of the converter.