SLUAAR3 December   2023 BQ27426 , BQ27427 , BQ27Z561 , BQ27Z746 , BQ28Z610 , BQ34Z100 , BQ40Z50 , BQ40Z80

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Voltage Correlation
  6. 3Voltage + IR Correction
  7. 4Coulomb Counting
  8. 5CEDV
  9. 6Impedance Track
  10. 7Algorithm Comparisons
    1. 7.1 Calculating SOC Error
      1. 7.1.1 Calculating True SOC
      2. 7.1.2 Finding Calculated SOC for Voltage Correlation & Voltage + IR Correction
      3. 7.1.3 Finding Calculated SOC for Coulomb Counting
    2. 7.2 Comparing SOC Error
  11. 8Summary
  12. 9References

7.2 Comparing SOC Error

The peak error for voltage correlation is around 20% for test 1 and 17% for test 2. The peak error for voltage + IR correction isaround 11% for test 1 and 10% for test 2. The peak error for coulomb counting is about 6% for both test 1 and 2, assuming the FCC was not learned. On subsequent cycles, assuming temperature and load is similar, coulomb counting can have low error. The peak error for Impedance Track is about 1% for both test 1 and 2.

CEDV accuracy is very similar to the coulomb counter error, so the CEDV is not shown in the graphical comparison for these load profile examples.

GUID-542430F2-CC9B-4DB5-93F0-B35F175754E0-low.png Figure 7-3 Voltage Correlation SOC Error for Test 1 and 2
GUID-0F897305-E3E8-4C28-A558-EDF071A5652C-low.png Figure 7-4 Voltage + IR Correction SOC Error for Test 1 and 2
GUID-BF775437-14A2-45DD-AD5D-9F20E1C419C7-low.png Figure 7-5 Coulomb Counting SOC Error for Test 1 and 2
GUID-8DFBBB17-444D-4EE9-A9FC-7B11EBC77A4C-low.png Figure 7-6 Impedance Track SOC Error for Test 1 and 2