Patent ID: 9065349
Filing Date: 2015-06-23
Classification: H02M,Y02B

Abstract:
1. A control method comprising: operating a bidirectional DC-DC converter in a boost mode, with the bidirectional DC-DC converter including a high voltage side and a low voltage side, with the low voltage side provided with a plurality of low-voltage-side switches, a voltage clamping switch and a voltage clamping capacitor, with the plurality of low-voltage-side switches including a plurality of first low-voltage-side switches and a plurality of second low-voltage-side switches; alternatively switching on and off the plurality of first low-voltage-side switches and the plurality of second low-voltage-side switches including cutting off the plurality of first low-voltage-side switches or the plurality of second low-voltage-side switches and utilizing the voltage clamping capacitor to clamp a voltage via a diode reversely parallel-connected to the voltage clamping switch situated in a cut-off state, with switching on the voltage clamping switch prior to switching on all of the plurality of low-voltage-side switches to discharge power energy of the voltage clamping capacitor and to switch on the plurality of first low-voltage-side switches or the plurality of second low-voltage-side switches by a zero-voltage switching operation, thereby reducing a duty cycle of switching the voltage clamping switch; and switching on the voltage clamping switch with a predetermined duty cycle with a switching-on time interval at a first point of a turn-off time interval of at least one set of the plurality of low-voltage-side switches prior to nearly switching on all of the plurality of low-voltage-side switches and switching off the voltage clamping switch at a second point prior to alternatively switching on the at least one set of the plurality of low-voltage-side switches; wherein the switching-on time interval of the voltage clamping switch is smaller than a turn-off time interval and a period of charging and discharging time of the voltage clamping capacitor is reduced due to reduction of the duty cycle of switching the voltage clamping switch.