The gate signals of the CFHB are the inverse of the VFHB. Namely, power switches of the CFHB are driven with alternative signals, shifted 180 . According to the switching states, one cycle of the CFHB is divided into four separate modes and two of them are identified in Fig. 2. The other two modes are symmetrical to those in Fig. 2. Mode 1 corresponds to the interval when both switches are turned on. Mode 2 corresponds to the interval when one of the switches is turned off and the other is still turned on. turned off and the other is still turned on.