The asymmetric cascaded H-bridge was introduced by Mitsubishi and features three series-connected H-bridge cells operating with unequal dc voltage ratios . The PV system is connected through a boost dc-dc stage to only one of the H-bridge cells,which is the only one processing active power to the grid. The other two cells use floating dc links for power quality improvement through the generation of 13 voltage levels. This enables a reduc-tion of the switching frequency without compromising the power quality. The topology requires abidirectional bypass switch connected to the large cell to reduce the changing potential between the PV system andthe ground to reduce the possibility of leakage currents and enable transformerless operation