POWER SUPPLY DEVICE

摘要

In a power supply device, the bridge circuit is configured by connecting, in parallel, a plurality of series circuits of an inverse-parallel connection circuit of a semiconductor switch and a diode. A control unit controls switching of a semiconductor switch so that a voltage v between AC terminals becomes zero voltage in equal periods α before and after a center point shifted from one zero crossing point in one cycle of the input current by a compensation period (angle) β calculated from a voltage applied to a resonance circuit constituted by the power receiving coil and a resonance capacitor Cr and an induced voltage of the power receiving coil, and becomes a positive-negative voltage whose peak value is the voltage Vo between DC terminals in other periods.

主权项

1. A power supply device comprising:
a power receiving coil configured to exchange power by an external magnetic coupling; a bridge circuit in which one end of the power receiving coil is connected to one alternating-current (AC) terminal through a resonance capacitor configuring a resonance circuit with the power receiving coil, and another end of the power receiving coil is connected to another AC terminal; and a smoothing capacitor connected between direct-current (DC) terminals of the bridge circuit,wherein
a load is connected to both ends of the smoothing capacitor; and the bridge circuit comprises, at least for one phase, a switching arm series circuit in which two inverse-parallel connection circuits of a semiconductor switch and a diode are connected in series,wherein the power supply device comprises:
a current detecting unit configured to detect an input current flowing in the power receiving coil; a voltage detecting unit configured to detect a voltage between DC terminals of the bridge circuit; and a control unit configured to perform switching of the semiconductor switch;wherein
the control unit performs switching of the semiconductor switch so that a voltage between AC terminals of the bridge circuit becomes zero voltage in equal periods before and after a center point shifted from one zero crossing point in one cycle of the input current by a compensation period calculated from a voltage applied to the resonance circuit and an induced voltage of the power receiving coil, and becomes a positive-negative voltage whose peak value is the voltage between DC terminals in other periods.