A Z-source sparse matrix converter under a voltage sag condition

This paper presents a Z-source sparse matrix converter (ZSMC) system and control for general-purpose adjustable speed drive (ASD) systems under input voltage sag condition. The ZSMC is developed based on the structure of a sparse matrix converter (SMC) to reduce the number of unipolar power semiconductor switches. It also employs a Z-source network to overcome the inherent limitation of the low voltage transfer ratio of a traditional matrix converter. By controlling a shoot-through interval, the ZSMC can achieve any desired voltage transfer ratio, even greater than unity. The ZSMC can control the input power factor independently regardless of the loads and its structure also allows bidirectional power flow. These advantageous features of the ZSMC show great promise of success in the ASD systems. Analysis, simulation, and experimental results will be presented to verify the advantageous features of the ZSMC based ASD system.