Patent ID: 8711587
Filing Date: 2014-04-29
Classification: H02M

Abstract:
1. A power converter, comprising: an active converter that includes a semiconductor element, is supplied with an AC voltage from an AC power source, rectifies the AC voltage into a DC voltage, and raises the DC voltage to an arbitrary DC voltage; a smoothing capacitor that is connected to an output side of the active converter with a DC load connected to both ends of the smoothing capacitor, and smoothes the DC voltage output from the active converter; a current limiting resistor that is connected between the AC power source and the active converter, and limits a current flowing from the AC power source; a switching unit that is connected in parallel with the current limiting resistor; a DC voltage detecting unit detecting a bus voltage that is a voltage across the smoothing capacitor; and a control device that controls a voltage-raising operation of the DC voltage output from the active converter, wherein the control device turns on the switching unit in a case where the AC voltage is output from the AC power source, and turns off the switching unit in a case where a power failure occurs in the AC power source, the control device stops an operation of the DC load when it is determined that the bus voltage detected by the DC voltage detecting unit is equal to or less than a predetermined reference voltage, and when the bus voltage of the active converter is varied by the control device, the predetermined reference voltage is also varied in conjunction with variation of the bus voltage.