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 resonance capacitor forming a resonance circuit with the power receiving coil; a bridge circuit having alternating-current (AC) terminals and direct-current (DC) terminals, one end of the power receiving coil being connected to one of the AC terminals through the resonance capacitor, and another end of the power receiving coil being connected to another of the AC terminals, the bridge circuit including at least for one phase, a plurality of switching arm series circuits, each switching arm series circuit having two inverse-parallel connection circuits connected in series, each inverse-parallel connection circuit having a semiconductor switch and a diode connected in inverse-parallel; a smoothing capacitor connected between the DC terminals of the bridge circuit; a load connected to both ends of the smoothing capacitor; 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 the DC terminals of the bridge circuit; and a control unit configured to perform switching of the semiconductor switch so that a voltage between the 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 and becomes a positive-negative voltage whose peak value is the voltage between DC terminals in other periods, the compensation period being calculated according to an amplitude of a fundamental wave component of the voltage between the AC terminals of the bridge circuit achieved when a phase of the input current detected by the current detecting unit matches a phase of an induced voltage of the power receiving coil, and being indicated using a voltage applied to the resonance circuit and the induced voltage of the power receiving coil.