Vehicle having a DC-DC converter, and a method of controlling the DC-DC converter for a vehicle

Patent metadata

Field	Value
Publication number	US-10293705-B2
Application number	US-201715463034-A
Country	US
Kind code	B2
Filing date	Mar 20, 2017
Priority date	Nov 22, 2016
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

A vehicle may include a first battery to output power of a first voltage, a second battery to output power of a second voltage, a DC-DC converter to convert the first voltage of the first battery into the second voltage, and to supply the power of the second voltage to the second battery. The DC-DC converter may include a transformer to convert the first voltage into the second voltage, a first switch to control first current input to the transformer from the first battery, a current sensor to measure a value of second current output to the second battery from the transformer, and a controller to turn on/off the first switch based on a set turning-on/off frequency. The controller may delay turning-on/off of the first switch based on the measured value of the second current.

First claim

What is claimed is:

1. A vehicle comprising:
a first battery configured to output power of a first voltage;
a second battery configured to output power of a second voltage; and
a DC-DC converter configured to convert the first voltage of the first battery into the second voltage, and configured to supply the power of the second voltage to the second battery,
wherein the DC-DC converter comprises:
a transformer configured to convert the first voltage into the second voltage;
a first switch configured to control a first current input to the transformer from the first battery;
a current sensor configured to measure a value of a second current output to the second battery from the transformer; and
a controller configured to turn on/off the first switch based on a set turning-on/off frequency,
wherein the controller is configured to delay turning-on or turning-off of the first switch based on the measured value of the second current.

2. The vehicle according to claim 1 , wherein the controller is configured to increase a dead time for delaying turning-on of the first switch as the measured value of the second current decreases.

3. The vehicle according to claim 2 , further comprising a voltage sensor configured to measure a value of the first voltage of the first battery.

4. The vehicle according to claim 3 , wherein the controller is configured to decrease the dead time as the measured value of the first voltage decreases.

5. The vehicle according to claim 3 , wherein the controller is configured to calculate the dead time from the measured value of the first voltage and the measured value of the second current.

6. The vehicle according to claim 3 , wherein the controller is configured to acquire a dead time corresponding to the measured value of the first voltage and the measured value of the second current, from a lookup table including a plurality of values for the first voltage, a plurality of values for the second current, and a plurality of dead times corresponding to the plurality of values for the first voltage and the plurality of values for the second current.

7. The vehicle according to claim 1 , wherein the DC-DC converter further comprises:
a reset capacitor configured to reset a primary coil of the transformer; and
a second switch configured to control reset current of the reset capacitor;
wherein the controller turns on the second switch after the first switch is turned off, and turns on the second switch after the second switch is turned off.

8. The vehicle according to claim 7 , wherein the controller is configured to turn on the first switch when a dead time elapses after the second switch is turned off.

9. The vehicle according to claim 8 , wherein the controller is configured to increase the dead time as the measured value of the second current decreases.

10. The vehicle according to claim 1 , wherein a voltage of both terminals of the first switch is changed by a resonance phenomenon caused by leakage inductance of the transformer and parasitic capacitance of the first switch, and wherein the controller is configured to turn on the first switch when the voltage of the both terminals of the first switch becomes a minimum value by the resonance phenomenon.

11. The vehicle according to claim 1 , wherein the DC-DC converter further comprises a rectifier circuit configured to rectify a voltage and current that are output from the transformer.

12. A DC-DC converter of a vehicle for converting a first voltage output from a first battery into a second voltage output from a second battery, the DC-DC converter comprising:
a transformer including a primary coil connected to the first battery and a secondary coil connected to the second battery, and configured to convert the first voltage into the second voltage;
a first switch connected in series to the transformer;
a reset capacitor connected in parallel to the primary coil;
a second switch connected in series to the reset capacitor;
a voltage sensor configured to measure a value of the first voltage;
a current sensor configured to measure a value of second current output from the secondary coil; and
a controller configured to turn on/off the first switch and the second switch based on an operating frequency,
wherein the controller is configured to delay turning-on of the first switch based on the measured value of the first voltage and the measured value of the second current.

13. The DC-DC converter according to claim 12 , wherein the controller turns on the first switch when a dead time elapses after the second switch is turned off.

14. The DC-DC converter according to claim 13 , wherein the controller is configured to increase the dead time as the measured value of the second current decreases.

15. The DC-DC converter according to claim 13 , wherein the controller is configured to decrease the dead time as the measured value of the first voltage decreases.

16. The DC-DC converter according to claim 13 , wherein the controller is configured to calculate the dead time from the measured value of the first voltage and the measured value of the second current.

17. The DC-DC converter according to claim 13 , wherein the controller is configured to acquire a dead time corresponding to the measured value of the first voltage and the measured value of the second voltage, from a lookup table including a plurality of values for the first voltage, a plurality of values for the second current, and a plurality of dead times corresponding to the plurality of values for the first voltage and the plurality of values for the second voltage.

18. The DC-DC converter according to claim 13 , further comprising a rectifier circuit configured to rectify a voltage and current that are output from the transformer.

19. A method of controlling a DC-DC converter of a vehicle including a transformer configured to convert a first voltage of a first battery into a second voltage of a second battery, a first switch configured to control a first current input to the transformer, a reset capacitor configured to reset a primary coil of the transformer, and a second switch configured to control reset current of the reset capacitor, the method comprising:
turning on the second switch to reset the primary coil of the transformer;
turning off the second switch;
measuring a value of second current output from a secondary coil of the transformer;
measuring a value of the first voltage of the first battery;
deciding a dead time for delaying turning-on of the first switch based on the measured value of the second current and the measured value of the first voltage;
turning on the first switch after the dead time elapses; and
turning off the first switch.

20. The method according to claim 19 , wherein the dead time increases as the measured value of the second current decreases.

21. The method according to claim 19 , wherein the dead time decreases as the measured value of the first voltage decreases.

22. The method according to claim 19 , wherein the deciding of the dead time comprises, by a processor, calculating the dead time from the measured value of the first voltage and the measured value of the second current.

23. The method according to claim 19 , wherein the deciding of the dead time comprises:
storing a lookup table including a plurality of values for the first voltage, a plurality of values for the second current, and a plurality of dead times corresponding to the plurality of values for the firs

Assignees

• Hyundai Motor Co Ltd

Inventors

• Lee Dae Woo
• Lee Woo Young
• Kim Jun Ho
• Ha Taejong
• Cha Jaeeun
• Yang Jin Myeong
• Yeo Inyong

Classifications

• H02J7/342

  The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging (with circuits for polarity protection H02J7/68) · CPC title

• H02M3/33546

  with automatic control of the output voltage or current (H02M3/33561 takes precedence) · CPC title

• B60Y2400/3086

  Electric voltages sensors · CPC title

• B60L50/16

  with provision for separate direct mechanical propulsion · CPC title

• B60L58/10

  for monitoring or controlling batteries · CPC title