Apparatus and method for alleviating voltage drop of battery cell

• US 9,409,485 B2
• Filed: 11/18/2014
• Issued: 08/09/2016
• Est. Priority Date: 07/14/2014
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Shin, Jin-Cheol, Kim, Yong-Chan, Lee, Hee-Jin
• Primary Examiner(s): FLETCHER, MARLON T
• Application Number:
  US14/546,813
• Publication Number:
  US 20160009184A1
• Time in Patent Office: 630 Days
• US Class Current: 1/1
• CPC Class Codes: B60L 15/2036 Electric differentials, e.g. for supporting steering vehicles
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 50/15 with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02P 29/032 Preventing damage to the motor, e.g. setting individual current limits for different drive conditions
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

An apparatus for alleviating a voltage drop of a battery cell includes a battery having a plurality of battery cells, a sensor configured to sense the battery to generate sensing information, a calculator configured to calculate an allowable torque of a motor using the sensing information and calculate an expected voltage of the battery using the allowable torque and the sensing information, and a determinator configured to control a torque quantity of the motor using the expected voltage and a reference voltage.

Claims

1. An apparatus for alleviating a voltage drop of a battery cell, comprising:

a battery having a plurality of battery cells;

a sensor sensing the battery to generate sensing information;

a calculator calculating an allowable torque of a motor using the sensing information and calculating an expected voltage of the battery using the allowable torque and the sensing information; and

a determinator configured to control a torque quantity of the motor using the expected voltage and a preset reference voltage,

wherein the reference voltage is increased by an extension of arrival time of the reference voltage to the maximum allowable power, and wherein the determinator reduces the torque quantity of the motor when the expected voltage is smaller than the reference voltage and uses the torque quantity corresponding to the maximum allowable power when the expected voltage is higher than the reference voltage.

2. The apparatus of claim 1, wherein the calculator calculates the expected voltage using maximum allowable power of the battery, an allowable torque within a range of the maximum allowable power, a current voltage slope, and a change quantity of revolution per minute (RPM) of the motor.

3. The apparatus of claim 2, wherein the current voltage slope is calculated by a power usage of the battery at a position of a current voltage.

4. The apparatus of claim 2, wherein the change of quantity of the RPM is a change of quantity of RPM to the maximum allowable power at a current point.

5. The apparatus of claim 2, wherein the expected voltage is calculated by the following Equation:

Expected Voltage=Current Voltage−

Dv/d (RPM)×

Change Quantity Of RPM

In the above Equation, dV/d (RPM) represents a voltage slope, dV represents previous voltage−

current voltage and d (RPM) represents current RPM−

previous RPM.

6. The apparatus of claim 1, wherein the sensing information includes a state of charge (SOC), a state of health (SOH), a temperature, and a voltage of the battery.

7. The apparatus of claim 1, wherein the maximum allowable power is any one of 60 kW limit, 80 kW limit, and 40 kW limit.

8. A method for alleviating a voltage drop of a battery cell, comprising:

sensing a battery having a plurality of battery cells to generate sensing information;

calculating an allowable torque of a motor using the sensing information;

calculating an expected voltage of the battery using the allowable torque and the sensing information; and

controlling a torque quantity of the motor using the expected voltage and a preset reference voltage,

wherein the reference voltage is increased by an extension of arrival time of the reference voltage to the maximum allowable power and the controlling of the torque quantity includes the steps of;

comparing the expected voltage with the reference voltage;

reducing the torque quantity of the motor when the expected voltage is smaller than the reference voltage; and

using the torque quantity corresponding to maximum allowable power when the expected voltage is higher than the reference voltage.

9. The method of claim 8, wherein the expected voltage is calculated using maximum allowable power of the battery, an allowable torque within a range of the maximum allowable power, a current voltage gradient, and a change quantity of revolution per minute (RPM) of the motor.

10. The method of claim 9, wherein the current voltage slope is calculated by a power usage of the battery at a position of a current voltage.

11. The method of claim 9, wherein the change quantity of the RPM is a change quantity of RPM to the maximum allowable power at a current point.

12. The method of claim 9, wherein the expected voltage is calculated by the following Equation:

Expected Voltage=Current Voltage−

Dv/d (RPM)×

Change Quantity Of RPM

In the above Equation, dV/d (RPM) represents a voltage slope, dV represents previous voltage−

current voltage and d (RPM) represents current RPM−

previous RPM.

13. The method of claim 8, wherein the sensing information includes a state of charge (SOC), a state of health (SOH), a temperature, and a voltage of the battery.

14. The method of claim 8, wherein the maximum allowable power is any one of 60 kW limit, 80 kW limit, and 40 kW limit.

15. A non-transitory computer readable medium including instructions, which cause a controller to perform the steps in the method of claim 8.