United converter apparatus and operating method thereof

1. A united converter apparatus comprising:

a high-voltage charger configured to charge a high-voltage battery, using commercial power; and

a low-voltage charger configured to charge a low-voltage battery, using the high-voltage battery, wherein the high-voltage charger includes:

a voltage stabilizer configured to stabilize a DC component of a voltage, and

a voltage level adjustment circuit, wherein the voltage level adjustment circuit is configured to:

boost a voltage of the commercial power to apply the boosted voltage to the high-voltage battery,

drop a voltage from the high-voltage battery to apply the dropped voltage to the low-voltage charger, and

boost a level of a voltage output from the voltage stabilizer to a predetermined level to apply the boosted voltage to the high-voltage battery.

2. The united converter apparatus of claim 1 , wherein the high-voltage charger includes:

a first filter configured to reduce a noise of the commercial power;

a power factor correction circuit configured to convert an AC component of the commercial power to a DC component of the commercial power and to compensate for a low frequency ripple;

a first switching circuit module configured to convert the DC component of a voltage applied from the power factor correction to an AC component of the voltage;

a transformer configured to change a level of the voltage output by the first switching circuit module; and

a second switching circuit module configured to convert an AC component of a voltage applied from the transformer to the DC component of the voltage.

3. The united converter apparatus of claim 2 , wherein the

voltage stabilizer is configured to stabilize the voltage applied from the second switching circuit module.

4. The united converter apparatus of claim 3 , wherein the voltage stabilizer includes a capacitor.

5. The united converter apparatus of claim 3 , wherein the voltage stabilizer stabilizes the voltage dropped by the voltage level adjustment circuit.

6. The united converter apparatus of claim 5 , wherein the low-voltage charger includes:

a third switching circuit module configured to convert a DC component of the voltage applied from the voltage stabilizer, to an AC component of the voltage;

a transformer configured to convert the voltage applied from the third switching circuit module; and

a rectifier configured to rectify the voltage applied from the transformer to apply the rectified voltage to the low-voltage battery.

7. The united converter apparatus of claim 1 , further comprising:

a second filter configured to reduce a noise of the boosted voltage output from the voltage level adjustment circuit.

8. The united converter apparatus of claim 7 , wherein the second filter is configured to:

when the low-voltage battery is charged, reduce a noise of the voltage applied from the high-voltage battery.

9. The united converter apparatus of claim 1 , wherein the voltage level adjustment circuit is configured to:

when the low-voltage battery is charged, drop a level of the voltage from the high-voltage battery to a predetermined level for applying to the low-voltage battery.

10. The united converter apparatus of claim 1 , wherein the voltage level adjustment circuit includes:

an inductor configured to perform charging the boosted voltage or discharging a voltage the high-voltage battery;

a first switch and a second switch configured to perform transmission or blocking of the voltage; and

a capacitor configured to perform charging the boosted voltage or discharging a voltage of the high-voltage battery.

11. The united converter apparatus of claim 1 , wherein the voltage level adjustment circuit includes:

a first switch and a second switch connected to each other in series;

an inductor, one end of which is connected to a common node of the first switch and the second switch; and

a capacitor connected in parallel with the first switch and the second switch.

12. A method of operating a united converter apparatus, the method comprising:

converting an AC component of a commercial power to a DC component and compensating for a low frequency ripple;

converting a DC component of a voltage, in which the low frequency ripple is compensated, to a further AC component;

converting the further AC component to a further DC component;

stabilizing a voltage of the further DC component;

boosting the stabilized voltage of the further DC component to a predetermined high-voltage level; and

applying the boosted stabilized voltage to a high-voltage battery to charge the high-voltage battery.

13. The method of claim 12 , further comprising:

removing noise of the commercial power; and

removing a noise of the boosted voltage.

14. A method of operating a united converter apparatus, the method comprising:

dropping a voltage from a high-voltage battery to a predetermined level;

converting a DC component of the dropped voltage to an AC component;

converting and rectifying a voltage of the AC component;

applying the rectified voltage to a low-voltage battery to charge the low-voltage battery;

reducing a noise of the high-voltage battery;

stabilizing the dropped voltage;

converting a DC component of the stabilized dropped voltage, to an AC component of the stabilized dropped voltage;

transforming the AC component of the stabilized dropped voltage; and

rectifying the transformed AC component of the stabilized dropped voltage to apply the rectified voltage to the low-voltage battery.