On-board charger and DC-DC converter architecture for balancing of voltages or currents between batteries in electric vehicle battery systems
An electric vehicle battery system is provided. In some embodiments, the electric vehicle battery system can comprise a battery pack comprising a first battery and a second battery. In various embodiments, a first bidirectional direct current to alternating current (DC-AC) converter can be electrically coupled to the first battery and to a first bidirectional high-voltage (HV) alternating current to direct current (AC-DC) converter. In various implementations, a second bidirectional DC-AC converter can be coupled to the second battery and to a second bidirectional HV AC-DC converter. In further embodiments, and a power factor correction AC-DC module can be electrically coupled to the first bidirectional HV AC-DC converter via a first switch and the second bidirectional HV AC-DC converter via a second switch.
1. An electric vehicle battery system, comprising:
a battery pack comprising a first battery and a second battery;
a first bidirectional direct current to alternating current (DC-AC) converter electrically coupled to: the first battery, a first bidirectional high-voltage (HV) alternating current to direct current (AC-DC) converter, and a first bidirectional low-voltage (LV) AC-DC converter;
a second bidirectional DC-AC converter coupled to: the second battery, a second bidirectional HV AC-DC converter, and a second bidirectional LV AC-DC converter;
a first LV output connected to the first bidirectional LV AC-DC converter, and a second LV output connected to the second bidirectional LV AC-DC converter, wherein the second battery powers the first LV output using the first bidirectional HV AC-DC converter and the second bidirectional HV AC-DC converter; and
a power factor correction AC-DC module electrically coupled to:
the first bidirectional HV AC-DC converter via a first switch; and
the second bidirectional HV AC-DC converter via a second switch.
2. The electric vehicle battery system of claim 1 , wherein the second battery charges the first battery using the first bidirectional HV AC-DC converter and the second bidirectional HV AC-DC converter until a first voltage of the first battery equals a second voltage of the second battery.
3. The electric vehicle battery system of claim 1 , wherein the second battery is charged from the first battery using the first bidirectional HV AC-DC converter and the second bidirectional HV AC-DC converter.
4. The electric vehicle battery system of claim 1 , wherein the first battery powers the second LV output using the first bidirectional HV AC-DC converter and the second bidirectional HV AC-DC converter.
5. The electric vehicle battery system of claim 1 , wherein the first LV output comprises 12 volt (V) or 48V.
6. The electric vehicle battery system of claim 1 , further comprising:
a third LV output electrically coupled to:
the first LV output via a third switch; and
the second LV output via a fourth switch.
7. The electric vehicle battery system of claim 6 , wherein the third LV output draws current from the first battery until a first voltage of the first battery equals a second voltage of the second battery.
8. The electric vehicle battery system of claim 1 , wherein the first switch and the second switch comprise metal-oxide-semiconductor field-effect transistors (MOSFETs) or insulated-gate bipolar transistors (IGBTs).
9. The electric vehicle battery system of claim 1 , wherein the first battery and the second battery each comprise 400 volt (V) or 200V.
10. A method, comprising:
determining, by a system comprising a processor:
a first voltage of a first battery of a battery pack of an electric vehicle, and
a second voltage of a second battery of the battery pack;
in response to determining, by the system, that the first voltage is different from the second voltage, balancing, by the system, using one or more power factor correction alternating current to direct current (AC-DC) modules, two or more bidirectional direct current to alternating current (DC-AC) converters, and two or more bidirectional high-voltage (HV) AC-DC converters, the first voltage of the first battery and the second voltage of the second battery; and
powering, by the system, a first low-voltage (LV) output via the second battery using a first bidirectional HV AC-DC converter and a second bidirectional HV AC-DC converter of the two or more bidirectional HV AC-DC converters, wherein a first bidirectional LV AC-DC converter is electrically coupled to a first bidirectional DC-AC converter of the two or more bidirectional DC-AC converters, a second bidirectional LV AC-DC converter is electrically coupled to a second bidirectional DC-AC converter of the two or more bidirectional DC-AC converters, the first LV output is connected to the first bidirectional LV AC-DC converter, and a second LV output is connected to the second bidirectional LV AC-DC converter.
11. The method of claim 10 , wherein the balancing occurs during charging of the electric vehicle from an external power source.
12. The method of claim 10 , wherein the balancing occurs during driving of the electric vehicle.
13. The method of claim 10 , further comprising:
powering, by the system, the second LV output via the first battery using the first bidirectional HV AC-DC converter and the second bidirectional HV AC-DC converter.
14. The method of claim 10 , wherein the second battery charges the first battery using the first bidirectional HV AC-DC converter and the second bidirectional HV AC-DC converter until the first voltage of the first battery equals the second voltage of the second battery.
15. The method of claim 10 , wherein the first battery charges the second battery using the first bidirectional HV AC-DC converter and the second bidirectional HV AC-DC converter until the first voltage of the first battery equals the second voltage of the second battery.
16. The method of claim 10 , wherein the first LV output comprises 12 volt (V) or 48V.
17. The method of claim 10 , wherein the second LV output comprises 12 volt (V) or 48V.
18. The method of claim 10 , further comprising:
electrically coupling, by the system, a third LV output to:
the first LV output via a third switch, and
the second LV output via a fourth switch.
19. The method of claim 18 , wherein the third LV output draws current from the first battery until the first voltage of the first battery equals the second voltage of the second battery.
20. The method of claim 18 , wherein the third switch and the fourth switch comprise metal-oxide-semiconductor field-effect transistors (MOSFETs) or insulated-gate bipolar transistors (IGBTs).