A recovery method for electric vehicle power balance fault recovery with constant capacity charging and discharging

A fault recovery and electric vehicle technology, applied in electric vehicles, secondary battery charging/discharging, battery/fuel cell control devices, etc., can solve problems such as inconsistent internal resistance, battery life decay, and inconsistent capacity of single batteries. Achieve the effect of improving accuracy and efficiency and eliminating voltage difference

Active Publication Date: 2019-02-22
天津力神新能源科技有限公司
View PDF8 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] After the electric vehicle has been used for a period of time, it needs to maintain its power system. The most common fault in the power system is the balance fault, that is, the voltage difference between the battery packs in the static state or the charging and discharging state is greater than the specified value. The main reason is that the capacity and internal resistance of the single cells are inconsistent, or the self-discharge rate of the battery is inconsistent, which will eventually lead to inconsistent charging and discharging between the single cells, which will reduce the overall capacity of the battery pack. At this time, the battery will not be restored. The lifetime will accelerate the decay
[0003] At present, there are mainly two methods of equalization in the power management system: active equalization and passive equalization. The equalization effect of the existing voltage equalization method is affected by the contact internal resistance, and when the voltage difference is not large, the charge and discharge current is small, and the equalization takes a long time.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A recovery method for electric vehicle power balance fault recovery with constant capacity charging and discharging
  • A recovery method for electric vehicle power balance fault recovery with constant capacity charging and discharging
  • A recovery method for electric vehicle power balance fault recovery with constant capacity charging and discharging

Examples

Experimental program
Comparison scheme
Effect test

specific Embodiment 1

[0030] Take a 92S32P ternary lithium 18650-ion battery pack as an example.

[0031] (a) Charging, the charging cut-off voltage is as Figure 4 shown.

[0032] (b) Discharge, the discharge cut-off voltage is as Figure 5 shown.

[0033] (c) Set equalization target parameters and equalization charge and discharge current:

[0034] The charging cut-off voltage difference specification is <13mV, the discharge cut-off voltage difference specification is <130mV, the balanced charging current is 6A, and the balanced discharging current is 6A. The system automatically calculates the balance charge and discharge time as shown in the table below, some batteries need to be charged, and some batteries need to be discharged.

[0035]

[0036]

[0037] (d) The comparison between the expected charging cut-off voltage after equalization and the actual charging cut-off voltage after equalization Image 6 shown.

[0038] (e) The comparison between the expected discharge cut-off volt...

specific Embodiment 2

[0041] Increase the balanced charging current and balanced discharging current, set the balanced target parameters and balanced charging and discharging current:

[0042]The charging cut-off voltage difference specification is <13mV, the discharge cut-off voltage difference specification is <130mV, the balanced charging current is 10A, and the balanced discharging current is 10A. The system automatically calculates the balance charge and discharge time as shown in the table below, some batteries need to be charged, and some batteries need to be discharged.

[0043] Rechargeable Battery

6#

11#

80#

85#

86#

Charging time (s)

48

16

112

178

48

discharge battery

65#

78#

89#

90#

Discharge time (s)

80

14

80

80

[0044] The equalization effect is as follows:

[0045]

[0046] As shown in the table above, after equalization, the charging voltage difference is reduced from 21mV to 13mV, t...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention relates to a balance failure recovery method for an electric vehicle power source capable of being charged and discharged in a fixed capacity mode. The technical problems that when balancing effects of existing voltage balance modes are influenced by contact internal resistance and the dropout voltage is not high, the electric current for charging and discharging is low, and balancing needs to be conducted for a long time are solved. The balance failure recovery method comprises the steps that (1) the charging cut-off voltage and the discharging cut-off voltage of all batteries are determined; (2) the rated charging and discharging cut-off voltage difference values are set, and the charging capacity and the discharging capacity of each battery are obtained; (3) the expected undercharged capacity, the expected residual discharging capacity, the expected charging cut-off voltage and the expected discharging cut-off voltage of each battery are obtained through charging and discharging curve piecewise linear fitting; and (4) each battery is charged and discharged in a fixed capacity mode, and failure recovery of the to-be-balanced power source is achieved. According to the balance failure recovery method, the batteries are externally charged or discharged in the fixed capacity mode and do not influenced by the contact internal resistance through the certain function relationship between the battery voltage and the battery capacitance in the charging terminal stage and the discharging terminal stage, the balanced current is high, and the time required by balancing is short.

Description

technical field [0001] The invention relates to a method for recovering a balanced fault of an electric vehicle power supply with constant-capacity charge and discharge, and belongs to the technical field of balanced fault recovery of the electric vehicle power supply. Background technique [0002] After the electric vehicle has been used for a period of time, it needs to maintain its power system. The most common fault in the power system is the balance fault, that is, the voltage difference between the battery packs in the static state or the charging and discharging state is greater than the specified value. The main reason is that the capacity and internal resistance of the single cells are inconsistent, or the self-discharge rate of the battery is inconsistent, which will eventually lead to inconsistent charging and discharging between the single cells, which will reduce the overall capacity of the battery pack. At this time, the battery will not be restored. The lifesp...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): B60L3/00B60L58/12B60L58/22H01M10/42H01M10/44
CPCB60L3/0046B60L58/13B60L58/22H01M10/4207H01M10/441Y02E60/10Y02T10/70
Inventor 莫治波谢利张彩云林燕
Owner 天津力神新能源科技有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products