Active-Power-Decoupling Method Using Differential AC Output for Single-Stage Single-Phase High- Frequency-Link Inverter

This paper proposes an active power decoupling (APD) method for single-stage single-phase high-frequency-link inverters (HFLIs) using differential ac output. The method directly compensates for the double-line-frequency (DLF) power at the ac port by controlling the common-mode (CM) component of the output capacitor voltages, thereby eliminating the need for conventional ac-side APD circuits. By taking advantage of the significant CM voltage fluctuation, this method eliminates the requirement for large electrolytic capacitors. A family of cycloconverter topologies with differential outputs, derived from conventional cycloconverters, is introduced to facilitate the implementation of the proposed APD method. As an example, the APD method is implemented and analyzed using an HFLI integrated with a buck-boost-type differential cycloconverter. Experimental results from a 48-V input, 220-V output prototype validate the effectiveness of the proposed APD method.