Method For Calculating Remaining Capacity Of Power Battery Pack
The present disclosure provides a method for calculating a remaining capacity of a power battery pack, which comprises steps of: (1) performing charging and discharging tests on a power battery pack provided with a battery management system with a charge-discharge machine; (2) reading C Bench — c and C Bench — d of the charge-discharge machine and reading C BMS — c and C BMS — d of the battery management system; (3) determining a charging correction coefficient K c and a discharging correction coefficient K d , K c = C Bench_c C BMS_c , K d = C Bench_d C BMS_d ; ( 4 ) determining a remaining capacity of the power battery pack: when the power battery pack is in a charged state, a variation of capacity ΔC c of the power battery pack is ΔC c =K c ×I×Δt, the remaining capacity C t of the power battery pack is C t =C 0 +ΔC c ; when the power battery pack is in a discharged state, a variation of capacity ΔC d of the power battery pack is ΔC d =K d ×I×Δt, the remaining capacity C t of the power battery pack is C t =C 0 −ΔC d .
1 . A method for calculating a remaining capacity of a power battery pack, comprising steps of:
(1) performing charging and discharging tests on a power battery pack provided with a battery management system with a charge-discharge machine;
(2) reading a charging capacity cumulative integral value C Bench — c of the charge-discharge machine and a discharging capacity cumulative integral value C Bench — d of the charge-discharge machine from a host computer of the charge-discharge machine, and reading a charging capacity cumulative integral value C BMS — c of the battery management system and a discharging capacity cumulative integral value C BMS — d of the battery management system from a CAN message of the battery management system;
(3) determining a charging correction coefficient K c and a discharging correction coefficient K d ,
where
the charging correction coefficient K c is:
K
c
=
C
Bench_c
C
BMS_c
the discharging correction coefficient K d is:
K
d
=
C
Bench_d
C
BMS_d
;
(4) determining a remaining capacity of the power battery pack:
when the power battery pack is in a charged state, a variation of capacity ΔC c of the power battery pack after a time quantum Δt is ΔC c =K c ×I×Δt, where, I is a charging current flowing through the power battery pack, the remaining capacity C t of the power battery pack is obtained by calculating by C t =C 0 +ΔC c ;
when the power battery pack is in a discharged state, a variation of capacity ΔC d of the power battery pack after a time quantum Δt is ΔC d =K d ×I×Δt, where, I is a discharging current flowing through the power battery pack, the remaining capacity C t of the power battery pack is obtained by calculating by C t =C 0 −ΔC d .
2 . The method for calculating the remaining capacity of the power battery pack according to claim 1 , wherein a current of the charge-discharge machine is 0 C˜1 C.
3 . The method for calculating the remaining capacity of the power battery pack according to claim 1 , wherein the charging and discharging tests are cycles of full charging and full discharging.
4 . The method for calculating the remaining capacity of the power battery pack according to claim 1 , wherein values of K c and K d are 0.8˜1.2.
5 . The method for calculating the remaining capacity of the power battery pack according to claim 4 , wherein when the values of K c and K d are not within the range of 0.8˜1.2, the values of K c and K d are 1 as default.