Z-source inverter for adjustable speed drives

This paper presents a Z-source inverter system and control for adjustable speed drives (ASD). The Z-source inverter employs a unique LC network to couple the inverter main circuit to the diode front end. By controlling the shoot-through duty cycle, the Z-source can produce any desired output AC voltage, even greater than the line voltage. As results, the new Z-source inverter system provides ride-through capability under voltage sags, reduces line harmonics, and extends output voltage range. Simulation results are presented to demonstrate the new features.