A reliable AC-AC converter with inverting and non-inverting operations

This paper proposes an ac-ac converter with bipolar voltage gain. It has both inverting and non-inverting operations. It has no shoot-through problem of voltage source or capacitor and can eliminate pulse-width modulation (PWM) dead-time between the switches, therefore high quality output ac power can be obtained and reliability of system can be improved greatly. The proposed converter can compensate both sags and swells in voltage if used as dynamic voltage restorer (DVR). For the compensation of voltage sags, inverting operation can be enabled. Similarly, for the compensation of voltage swells, non-inverting operation can be enabled. To verify the performance of the proposed converter, detailed analysis and experimental results are provided.