Power system of electric vehicle, electric vehicle comprising the same and method for heating battery group of electric vehicle

Patent metadata

Field	Value
Publication number	US-9308828-B2
Application number	US-201314403368-A
Country	US
Kind code	B2
Filing date	May 22, 2013
Priority date	May 22, 2012
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

A power system of an electric vehicle, an electric vehicle including the power system and a method for heating a battery group of the electric vehicle are provided. The power system of the electric vehicle includes: a battery group; a battery heater connected with the battery group; a battery management device connected with the battery group and the battery heater respectively, and configured to control the battery heater ( 102 ) to heat the battery group intermittently when a temperature of the battery group is lower than a first temperature threshold and a residual electric quantity of the battery group is larger than an electric quantity threshold; an electric distribution box; a motor; a motor controller connected with the motor and the electric distribution box respectively; and an isolation inductor.

First claim

What is claimed is:

1. A power system of an electric vehicle, comprising:
a battery group;
a battery heater, connected with the battery group and configured to charge and discharge the battery group to heat the battery group;
a battery management device, connected with the battery group and the battery heater respectively, and configured to control the battery heater to heat the battery group intermittently when a temperature of the battery group is lower than a first temperature threshold and a residual electric quantity of the battery group is larger than an electric quantity threshold;
an electric distribution box, configured to distribute a voltage output by the battery group;
a motor;
a motor controller, connected with the motor and the electric distribution box respectively, comprising a first input terminal, a second input terminal and a pre-charging capacitor connected between the first input terminal and the second input terminal, and configured to supply power to the motor according to a control command and a voltage distributed by the electric distribution box; and
an isolation inductor, connected between the battery group and the electric distribution box, wherein an inductance of the isolation inductor matches with a capacitance of the pre-charging capacitor.

2. The power system of claim 1 , wherein the battery management device is further configured to judge whether a heating time reaches a first preset time period and to control the battery heater to suspend heating the battery group when the heating time reaches the first preset time period.

3. The power system of claim 2 , wherein after controlling the battery heater to suspend heating the battery group, the battery management device is further configured to calculate a suspension time and control the battery heater to heat the battery group when the suspension time reaches a second preset time period.

4. The power system of claim 1 , further comprising:
a heating button, connected with the battery management device, wherein the battery management device sends a heating signal to the battery heater to control the battery heater to heat the battery group when the heating button is pressed.

5. The power system of claim 4 , wherein the battery management device is further configured to:
after controlling the battery heater to heat the battery group, when the heating button is pressed again, judge whether an operation of pressing the heating button satisfies a preset condition; and
when the operation of pressing the heating button satisfies the preset condition, indicate that the battery group is inhibited from one of being heated and being charged and the electric vehicle is inhibited from being driven.

6. The power system of claim 1 , wherein the battery management device is further configured to select a corresponding heating power according to the temperature of the battery group, and to control the battery heater to heat the battery group with the selected heating power.

7. The power system of claim 1 , wherein an inductance L of the isolation inductor is determined by a formula:
T=2π√{square root over (LC)}, where T is an equivalent load operational period of the motor and C is the capacitance of the pre-charging capacitor.

8. The power system of claim 1 , the battery heater is further configured to perform a failure self-test and send a test result to the battery management device.

9. The power system of claim 1 , wherein the battery heater comprises:
a first switch module, wherein a first terminal of the first switch module is connected with a first electrode of the battery group and the isolation inductor respectively;
a first capacitor, wherein a first terminal of the first capacitor is connected with a second terminal of the first switch module, and a second terminal of the first capacitor is connected with a second electrode of the battery group;
a first inductor, wherein a first terminal of the first inductor is connected with a node between the first switch module and the first capacitor; and
a second switch module, wherein a first terminal of the second switch module is connected with a second terminal of the first inductor, and a second terminal of the second switch module is connected with the second electrode of the battery group,
wherein a control terminal of the first switch module and a control terminal of the second switch module are connected with the battery management device, and the battery management device sends the heating signal to the control terminal of the first switch module and the control terminal of the second switch module to control the first switch module and the second switch module to turn on in turn so as to generate a charge current and a discharge current in turn, in which the first switch module is on when the second switch module is off, and the first switch module is off when the second switch module is on.

10. The power system of claim 1 , wherein the battery heater further comprises:
a cooling assembly configured to cool the first switch module and the second switch module.

11. The power system of claim 10 , wherein the cooling assembly comprises:
a wind channel arranged in the battery heater; and
a fan arranged at one end of the wind channel.

12. The power system of claim 10 , wherein the cooling assembly comprises:
a coolant channel arranged in the battery heater; and
a coolant inlet and a coolant outlet arranged in the battery heater respectively.

13. The power system of claim 1 , wherein the battery heater further comprises a power connector configured to connect and fasten a power cable connected to the battery group.

14. The power system of claim 1 , wherein the electric distribution box comprises:
a primary contactor, configured to distribute the voltage output by the battery group to power consumption equipment of the electric vehicle; and
a pre-charging-contactor, connected with one of the first input terminal and the second input terminal of the motor controller, and configured to charge the pre-charging capacitor under a control of the battery management device before the motor controller controls the motor to start.

15. An electric vehicle comprising a power system of claim 1 .

16. A method for heating a battery group of an electric vehicle, comprising:
detecting a temperature and a residual electric quantity of the battery group by a battery management device;
when the temperature of the battery group is lower than a first temperature threshold and the residual electric quantity of the battery group is larger than an electric quantity threshold, controlling a battery heater to heat the battery group intermittently;
when the temperature of the battery group is lower than the first temperature threshold and the residual electric quantity of the battery group is lower than the electric quantity threshold, indicating that the battery group is inhibited from one of being heated and being charged and the electric vehicle is inhibited from being driven by the battery management device;
judging whether a heating time reaches a first reset time period by the battery management device; and
controlling the battery heater to suspend heating the battery group when the heating time reaches the first preset time period.

17. The method of claim 16 , further comprising:
calculating a suspension time by the battery management device;
judging whether the suspension time reaches a second preset time period by the battery management device; and
controlling the battery heater to heat the battery group when the suspension time reaches

Assignees

• Byd Co Ltd

Inventors

• Wu Xingchi
• Wang Hongjun
• Xie Shibin

Classifications

• B60W10/08

  including control of electric propulsion units, e.g. motors or generators · CPC title

• B60L3/0023

  Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train · CPC title

• H01M10/5006

  Electricity · mapped topic

• B60L2240/545

  Temperature · CPC title

• H01M10/625

  Vehicles · CPC title