Charging system and method using motor driving system

Patent metadata

Field	Value
Publication number	US-11165275-B2
Application number	US-202016743912-A
Country	US
Kind code	B2
Filing date	Jan 15, 2020
Priority date	Aug 30, 2019
Publication date	Nov 2, 2021
Grant date	Nov 2, 2021

Abstract

A charging system and a charging method using a motor driving system are disclosed which may enable charging between vehicles each having a battery for providing power to a vehicle driving motor, such as electric vehicles or plug-in hybrid vehicles.

First claim

What is claimed is:

1. A charging system using a motor driving system comprising:
a first vehicle; and
a second vehicle,
wherein each of the first vehicle and the second vehicle further comprises:
a battery;
an inverter comprising:
a direct current (DC) link connected to the battery;
a plurality of motor connection terminals; and
a plurality of switching devices provided between the DC link and the plurality of motor connection terminals; and

a motor comprising a plurality of coils that is connected to the plurality of motor connection terminals to form a neutral point; and
a controller configured to:
determine a duty of the plurality of switching devices; and
control a voltage or current of the neutral point,

wherein, when the battery in the first vehicle or the second vehicle is charged by electrically interconnecting the neutral point in the first vehicle and the neutral point in the second vehicle, the controller is further configured to:
control the plurality of switching devices such that the voltage of each of the neutral points becomes a predetermined target voltage; and
control the plurality of switching devices such that the current of each of the neutral points becomes a predetermined target current.

2. The charging system of claim 1 , wherein the controller is configured to:
compare available voltages of the first vehicle and the second vehicle obtained by subtracting predetermined margins from voltages of the DC links; and
determine that a lower voltage of the available voltages is the predetermined target voltage.

3. The charging system of claim 2 , wherein:
the controller with the lower voltage of the available voltages is configured to control the duty of the plurality of switching devices such that the voltage of each of the neutral points becomes the predetermined target voltage, and
the controller with a higher voltage of the available voltages is configured to control the duty of the plurality of switching devices such that the current of each of the neutral points becomes the predetermined target current.

4. The charging system of claim 1 , wherein the controller is configured to:
obtain the available voltages of the first vehicle and the second vehicle by subtracting predetermined margins from voltages of the DC links;
compare the available voltage of the first vehicle with the DC link voltage of the second vehicle; and
determine that the compared DC link voltage is the predetermined target voltage when the available voltage of the first vehicle is higher than the DC link voltage of the second vehicle.

5. The charging system of claim 4 , wherein:
the controller of the second vehicle having the compared DC link voltage is configured to control the duty of the plurality of switching devices such that the voltage of each of the neutral points becomes the predetermined target voltage, and
the controller of the first vehicle having the compared available voltage is configured to control the duty of the plurality of switching devices such that the current of each of the neutral points becomes the predetermined target current.

6. The charging system of claim 4 , wherein the second vehicle having the compared DC link voltage further comprises:
a relay provided between the neutral point and DC link, wherein the controller of the second vehicle having the compared DC link voltage is configured to close the relay such that the voltage of each of the neutral points becomes the compared DC link voltage, and the controller of the first vehicle having the compared available voltage is configured to control the duty of the plurality of switching devices such that the current of each of the neutral points becomes the predetermined target current.

7. A charging method using the charging system, comprising:
detecting, by controllers of a first vehicle and a second vehicle, voltages of the DC links of the first vehicle and the second vehicle;
obtaining available voltages of the first vehicle and the second vehicle by subtracting predetermined margins of the first vehicle and the second vehicle from the detected DC link voltages;
setting, by the controllers of the first vehicle and the second vehicle, a target voltage of each of the interconnected neutral points of motors based on the DC link voltages and the available voltages;
controlling, by a controller of the first vehicle, a plurality of switching devices of an inverter in the first vehicle such that the voltage of each of the neutral points becomes the target voltage; and
controlling, by a controller of the second vehicle, a plurality of switching devices of the inverter and the second vehicle such that the current of each of the neutral points becomes a predetermined target current.

8. The charging method of claim 7 , wherein setting the target voltage comprises:
comparing the available voltages of the first vehicle and the second vehicle; and
determining that a lower voltage of the available voltages is the target voltage.

9. The charging method of claim 8 , wherein controlling the plurality of switching devices comprises:
controlling, by the controller with the lower voltage of the available voltages, the duty of the plurality of switching devices such that the voltage of each of the neutral points becomes the target voltage; and
controlling, by the controller with a higher voltage of the available voltages, the duty of the plurality of switching devices such that the current of each of the neutral points becomes the predetermined target current.

10. The charging method of claim 7 , wherein setting the target voltage comprises:
comparing the available voltage of the first vehicle with the DC link voltage of the second vehicle; and
determining that the compared DC link voltage is the target voltage when the available voltage of the first vehicle is higher than the DC link voltage of the second vehicle.

11. The charging method of claim 10 , wherein controlling the plurality of switching devices comprises:
controlling, by the controller of the second vehicle having the compared DC link voltage, the duty of the plurality of switching devices such that the voltage of each of the neutral points becomes the target voltage; and
controlling, by the controller of the first vehicle having the compared available voltage, the duty of the plurality of switching devices such that the current of each of the neutral points becomes the predetermined target current.

12. The charging method of claim 10 , wherein controlling the plurality of switching devices comprises:
closing, by the controller of the second vehicle having the compared DC link voltage, a relay provided between the neutral point and DC link such that the voltage of each of the neutral points becomes the compared DC link voltage; and
controlling, by the controller of the first vehicle having the compared available voltage, the duty of the plurality of switching devices such that the current of each of the neutral points becomes the predetermined target current.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Lee Yong Jae
• Hwang Jae Ho
• Park Joo Young
• Bae Su Hyun

Classifications

• H02J7/80

  including monitoring or indicating arrangements · CPC title

• H02J2105/37

  exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] · CPC title

• H02J7/90

  Regulation of charging or discharging current or voltage · CPC title

• H02J7/50

  acting upon multiple batteries simultaneously or sequentially · CPC title

• Y02T10/64

  Electric machine technologies in electromobility · CPC title