Power supply system including dc-to-dc converter and control method therefor

Abstract

A DC-DC converter including a bridge circuit unit electrically connected to a DC link capacitor and comprising at least one full bridge circuit comprising switching elements; a sensing unit for sensing a voltage between the bridge circuit unit and the DC link capacitor; and a control unit for controlling the bridge circuit unit according to the sensed voltage, wherein a power of one end of a battery is controlled to a droop curve-shaped power value according to the sensed voltage, wherein the DC-DC converter further comprises an inductor and a capacitor electrically connected to the bridge circuit unit, the inductor is connected to one end of a battery, the capacitor is connected to one end of the battery and a node on the other end of the battery, and the node is connected to and arranged between the inductor and the battery.

1 . A DC-DC converter comprising:
 a bridge circuit unit electrically connected to a DC link capacitor and comprising at least one full bridge circuit comprising switching elements;   a sensing unit for sensing a voltage between the bridge circuit unit and the DC link capacitor; and   a control unit for controlling the bridge circuit unit according to the sensed voltage,   wherein a power of one end of a battery is controlled to a droop curve-shaped power value according to the sensed voltage,   wherein the DC-DC converter further comprises an inductor and a capacitor electrically connected to the bridge circuit unit,   the inductor is connected to one end of a battery,   the capacitor is connected to one end of the battery and a node on the other end of the battery, and   the node is connected to and arranged between the inductor and the battery.   
     
     
         2 . The DC-DC converter of  claim 1 , wherein the control unit controls the bridge circuit unit so that a first power is supplied to the battery when the sensed voltage is greater than or equal to a first voltage. 
     
     
         3 . The DC-DC converter of  claim 2 , wherein the first power corresponds to a product of a first delta voltage that is a difference between the sensed voltage and the first voltage and a preset charging slope constant. 
     
     
         4 . The DC-DC converter of  claim 3 , wherein a droop curve of the droop curve-shaped control comprises a straight line with the preset charging slope, on which there is a point where the first voltage is associated with zero first power supported to the battery. 
     
     
         5 . The DC-DC converter of  claim 2 , wherein when the sensed voltage is less than or equal to a second voltage, wherein the control unit controls the bridge circuit so that a second power is discharged from the battery, and
 wherein the second voltage is lower than the first voltage.   
     
     
         6 . The DC-DC converter of  claim 5 , wherein the second power corresponds to a product of a second delta voltage that is a difference between the sensed voltage and the second voltage and a preset discharging slope constant. 
     
     
         7 . The DC-DC converter of  claim 6 , wherein a droop curve of the droop curve-shaped control comprises a straight line with the preset discharging slope, on which there is a point where the second voltage is associated with zero second power discharged from the battery. 
     
     
         8 . The DC-DC converter of  claim 6 , wherein the control unit controls the bridge circuit unit so that power of one end of the battery becomes zero when the sensed voltage is a voltage between the first voltage and the second voltage. 
     
     
         9 . The DC-DC converter of  claim 8 , wherein when the sensed voltage is greater than a third voltage, the control unit controls the bridge circuit unit, so that the first power corresponds to a product of the third voltage and a preset charging slope constant, and
 the third voltage is greater than the first voltage.   
     
     
         10 . The DC-DC converter of  claim 8 , wherein when the sensed voltage is greater than a fourth voltage, the control unit controls the bridge circuit unit so that the second power corresponds to a product of the fourth voltage and a preset charging slope constant, and
 the fourth voltage is smaller than the second voltage.   
     
     
         11 . A DC-DC converter comprising:
 a first bridge circuit unit;   a second bridge circuit unit   a transformer connected between the first bridge circuit unit and the second bridge circuit unit;   an LC circuit connected to the second bridge circuit, wherein the LC circuit is connected to a battery;   a sensing unit for sensing a voltage a first end of the first bridge circuit unit; and   a control unit for controlling the second bridge circuit unit according to the sensed voltage,   wherein a power of one end of a battery is controlled to a droop curve-shaped power value according to the sensed voltage,   wherein the LC circuit includes an inductor and a capacitor electrically connected to the second bridge circuit unit,   the inductor is connected to one end of a battery,   the capacitor is connected to one end of the battery and a node on the other end of the battery, and   the node is connected to and arranged between the inductor and the battery.   
     
     
         12 . The DC-DC converter of  claim 11 , wherein the control unit configured to control switching operations of the second bridge circuit so that a charging power corresponding to a first power supplied to the battery has a droop curve-shaped power value according to the sensed voltage. 
     
     
         13 . The DC-DC converter of  claim 12 , when the sensed voltage is greater than or equal to a first voltage, the first power corresponds to a product of a preset charging slope constant and a first delta voltage that is a difference between the sensed voltage and the first voltage, and
 wherein when the sensed voltage is less than or equal to a second voltage, the control unit is further configured to control the switching operations of the second bridge circuit unit so that a second power is discharged from the battery, and   wherein the second voltage is lower than the first voltage.   
     
     
         14 . The DC-DC converter of  claim 13 , wherein the second power corresponds to a product of a preset discharging slope constant and a second delta voltage that is a difference between the sensed voltage and the second voltage. 
     
     
         15 . The DC-DC converter of  claim 14 , wherein control unit is further configured to control the switching operations of the second bridge circuit unit so that a power supplied to the first end of the battery is zero when the sensed voltage is a voltage between the first voltage and the second voltage. 
     
     
         16 . A control method of charging/discharging of a battery of a DC-DC converter including a DC link capacitor, the battery, and a bridge circuit unit disposed between the DC link capacitor and the battery, wherein the bridge circuit unit comprises at least one full bridge circuit with switching elements;
 wherein the DC-DC converter further comprises an inductor and a capacitor electrically connected to the bridge circuit unit,   wherein the inductor is connected to one end of a battery,   wherein the capacitor is connected to one end of the battery and a node on the other end of the battery, and   wherein the node is connected to and arranged between the inductor and the battery,   wherein the control method of the DC-DC converter comprises:   sensing a voltage between the DC link capacitor and the bridge circuit; and   controlling the bridge circuit unit based on the sensed voltage,   wherein charge/discharge power of the battery is controlled to a droop curve-shaped power value according to the sensed voltage.   
     
     
         17 . The control method of the DC-DC converter of  claim 16 , wherein controlling the bridge circuit unit includes:
 charging the battery with a first power when the sensed voltage is greater than or equal to a first voltage; and   discharging the battery with a second power when the sensed voltage is less than or equal to a second voltage.   
     
     
         18 . The control method of the DC-DC converter of  claim 17 , wherein the first power corresponds to a product of a first delta voltage that is a difference between the sensed voltage and the first voltage and a preset charging slope constant. 
     
     
         19 . The control method of the DC-DC converter of  claim 17 , wherein the second power corresponds to a product of a second delta voltage that is a difference between the sensed voltage and the second voltage and a preset discharging slope constant. 
     
     
         20 . The control method of the DC-DC converter of  claim 16 , wherein the charging or discharging of the battery is stopped when the sensed voltage is a voltage between the first voltage and the second voltage.