US-12617300-B2 - Integrated vehicle power converter and battery charger

Abstract

Responsive to a voltage across a capacitor being greater than a voltage across a traction battery, a controller may open switches such that charge current from a DC charger flows through a diode to the traction battery without following through coils of an electric machine and without flowing through an inverter.

Inventors

• Petros G. Taskas
• BAOMING GE

Assignees

• FORD GLOBAL TECHNOLOGIES, LLC

Dates

Publication Date

20260505

Application Date

20230502

Claims (17)

1. 1 . A vehicle comprising: a traction battery; an electric machine; a bidirectional boost inverter electrically between the traction battery and electric machine; input circuitry including a capacitor, a diode, and a pair of series connected switches, wherein the pair of switches are connected between an AC charger and the bidirectional boost inverter; and one or more controllers programmed to, responsive to a voltage across the capacitor being greater than a voltage across the traction battery, open the pair of switches such that charge current from a DC charger electrically connected with the input circuitry flows through the diode to the traction battery without following through coils of the electric machine and without flowing through the inverter.
2. 2 . The vehicle of claim 1 , wherein the one or more controllers are further programmed to, responsive to the voltage across the capacitor being less than the voltage across the traction battery, open one of the pair of switches and close the other of the pair of switches such that charge current from the DC charger electrically connected with the input circuitry flows through the coils and the inverter to the traction battery.
3. 3 . The vehicle of claim 1 further comprising the AC charger.
4. 4 . The vehicle of claim 3 , wherein the one or more controllers are further programmed to, responsive to indication the AC charger is activated, close the pair of switches such that charge current from the AC charger flows through the coils and the inverter to the traction battery.
5. 5 . The vehicle of claim 1 , wherein the input circuitry further includes a connector for the DC charger and a connector for the AC charger.
6. 6 . The vehicle of claim 1 , wherein the capacitor, an anode of the diode, and the pair of switches share a common node.
7. 7 . The vehicle of claim 1 , wherein one of the pair of switches is directly electrically connected with the coils.
8. 8 . The vehicle of claim 1 , wherein the capacitor is electrically in parallel with the DC charger.
9. 9 . A method comprising: responsive to an indication a DC charger is electrically connected with a vehicle, and a voltage across a capacitor of the vehicle, electrically in parallel with the DC charger and connected at a common node between a pair of series connected switches of the vehicle, is greater than a voltage across a traction battery of the vehicle, opening the pair of switches such that charge current from the DC charger flows through a diode of the vehicle to the traction battery without flowing through coils of an electric machine of the vehicle and a bidirectional boost inverter of the vehicle; and responsive to the indication and the voltage across the capacitor being less than the voltage across the traction battery, opening one of the pair of switches and closing the other of the pair of switches such that charge current from the DC charger flows through the coils and the inverter to the traction battery.
10. 10 . The method of claim 9 further comprising, responsive to the indication and the voltage across the capacitor being less than the voltage across the traction battery, operating the inverter in a boost mode.
11. 11 . The method of claim 9 further comprising, responsive to indication an AC charger of the vehicle is activated, closing the pair of switches such that charge current from the AC charger flows through the coils and inverter to the traction battery.
12. 12 . The method of claim 11 further comprising operating the inverter in a boost mode.
13. 13 . An automotive power system comprising: one or more controllers programmed to, responsive to indication a DC charger is connected and a voltage across a capacitor is less than a voltage across a traction battery, open one of a pair of series connected switches and close another of the pair of switches such that charge current from the DC charger flows through coils of an electric machine and a bidirectional boost inverter to the traction battery, and responsive to indication an AC charger is activated, close the pair of switches such that charge current from the AC charger flows through the coils and inverter to the traction battery.
14. 14 . The system of claim 13 , wherein the one or more controllers are further programmed to operate the inverter in a boost mode.
15. 15 . The system of claim 13 , wherein the one or more controllers are further programmed to, responsive to indication a DC charger is connected and the voltage across the capacitor is greater than the voltage across the traction battery, open the pair of switches such that charge current from the DC charger flows through a diode to the traction battery without flowing through the coils and the inverter.
16. 16 . The system of claim 15 , wherein an anode of the diode is directly electrically connected with the pair of switches.
17. 17 . The system of claim 13 , wherein one of the pair of switches is directly electrically connected with the coils.

Description

TECHNICAL FIELD This disclosure relates to automotive power systems. BACKGROUND A vehicle may include an energy storage device, such as a traction battery, that provides power to an electric machine to propel the vehicle. This traction battery may be charged from an AC grid or DC fast charger. SUMMARY A vehicle includes a traction battery, an electric machine, an inverter electrically between then traction battery and electric machine, input circuitry including a capacitor, a diode, and a pair of series connected switches, and one or more controllers. The one or more controllers, responsive to a voltage across the capacitor being greater than a voltage across the traction battery, open the switches such that charge current from a DC charger electrically connected with the input circuitry flows through the diode to the traction battery without following through coils of the electric machine and without flowing through the inverter. A method includes, responsive to indication a DC charger is electrically connected with a vehicle, and a voltage across a capacitor of the vehicle electrically in parallel with the DC charger is greater than a voltage across a traction battery of the vehicle, opening a pair of switches of the vehicle such that charge current from the DC charger flows through a diode of the vehicle to the traction battery without flowing through coils of an electric machine of the vehicle or an inverter of the vehicle. The method further includes, responsive to the indication, and the voltage across the capacitor is less than the voltage across the traction battery, opening one of the switches and closing the other of the switches such that charge current from the DC charger flows through the coils and the inverter to the traction battery. An automotive power system includes one or more controllers that, responsive to indication a DC charger is connected and a voltage across a capacitor is less than a voltage across a traction battery, open one of a pair of series connected switches and close another of the switches such that charge current from the DC charger flows through coils of an electric machine and an inverter to the traction battery, and responsive to indication an AC charger is activated, close the switches such that charge current from the AC charger flows through the coils and inverter to the traction battery. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a vehicle. FIG. 2 is schematic diagram of another vehicle. DETAILED DESCRIPTION Embodiments are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments may take various and alternative forms. The figures are not necessarily to scale. Some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art. Various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations. 400V and 800V DC fast chargers are two types of charging systems that can be used for charging battery electric vehicles (BEVs). A 400V DC fast charger typically delivers a voltage range of 200V-500V and a current range of up to 500 A. This can provide a charge rate of up to 80% of a BEV's battery capacity in as little as 30 minutes, depending on the vehicle and the charger. 400V DC fast chargers are commonly found in public charging stations and can be used to charge most BEVs currently on the market. 800V DC fast chargers can deliver up to 800V and 400 A, allowing it to provide a higher charge rate than 400V DC fast chargers. This can result in faster charging times, typically allowing for an 80% charge in 15-20 minutes. 800V charging systems, however, are currently less common than 400V charging systems. BEVs with an 800V DC bus and an 800V traction battery are becoming more common. These systems will require an 800V DC fast charger. Referring to FIG. 1, a vehicle 10 includes an on-board charger 12, a traction battery 14 (e.g., an 800V battery), a DC link capacitor 16, an inverter 18, an electric machine 20, a switch 22, and a capacitor 24, and one or more controllers 26. The on-board charger 12 is connectable with an AC grid 28 as known in the art. The traction battery 14 is electrically connected in parallel between the on-board charger 12 and DC link capacitor 16. The DC link capacitor 16 is electrically connected in parallel between the tractio