With the low-carbon transformation of energy and electricity, the new energy automobile industry has developed rapidly. Bidirectional interactive technology applied to Vehicle to Grid (V2G) has attracted much attention in virtual power plant. With V2G technology, it is possible to enhance the operational efficiency of the power grid and improve the capacity for resource allocation. However, because of the wide range of global grid voltage or lithium battery voltage, the existing bidirectional converter cannot always work in the best efficiency state. This paper proposed a bidirectional AC-DC converter uses the concept of flexible converter and incorporates the merits of single-phase full-bridge grid-connected inverter and T-type three-level inverter. The converter has the flexibility to select the most efficient operating mode depending on the input voltage, thus minimizing converter losses. The proposed converter is suitable for V2G system in virtual power plant.