... 28–38, Spring 2007.[7] P. K. Jain, J. R. Espinoza, and H. Jin, “Performance of a single- stage UPSsystem for single- phase trapezoidal-shaped AC-voltage supplies,” IEEETrans. Power Electron., vol. ... controller. Furthermore,the underdamped state is designed for this two-order innerZHOU et al.: SINGLE- PHASE UNINTERRUPTIBLE POWER SUPPLY BASED ON Z-SOURCE INVERTER 3001TABLE I VSTEPRESPONSE ... switching period in steady-state operation is zero(uB− uC)T1+ uCT0=0 (6)ZHOU et al.: SINGLE- PHASE UNINTERRUPTIBLE POWER SUPPLY BASED ON Z-SOURCE INVERTER 3003Fig. 11. Experimental results....