Estimation method for whole life cycle cost of power battery in echelon utilization

Patent metadata

Field	Value
Publication number	US-11416899-B2
Application number	US-201916613608-A
Country	US
Kind code	B2
Filing date	Jan 8, 2019
Priority date	Jul 11, 2018
Publication date	Aug 16, 2022
Grant date	Aug 16, 2022

Abstract

Disclosed is an estimation method for a whole life cycle cost of a power battery in echelon utilization. In this method, echelon utilization grades are established for the power battery according to an SOH of the power battery; a whole battery capacity model is constructed corresponding to the echelon utilization grades; a cost model is constructed corresponding to the echelon utilization grades; and a variation trend of the whole life cycle cost of the power battery is estimated according to the echelon utilization grades for the power battery, the power battery capacity model and the cost model, and a result of estimation is outputted.

First claim

What is claimed is:

1. An estimation method for a whole life cycle cost of a power battery in echelon utilization, comprising:
establishing a plurality of echelon utilization grades for the power battery according to a scrapping standard of the power battery and an State Of Health (SOH) of the power battery; wherein the plurality of echelon utilization grades comprises: a first grade, corresponding to the SOH from 80% to 100%; a second grade, corresponding to the SOH from 40% to 80%; and a third grade, corresponding to the SOH from 0 to 40%;
constructing a whole battery capacity model corresponding to the echelon utilization grades;
constructing a cost model corresponding to the echelon utilization grades; and
estimating a variation trend and cost apportionment of the whole life cycle cost of the power battery according to the echelon utilization grades for the power battery, the power battery capacity model and the cost model; wherein the cost apportionment comprises the costs corresponding to the first stage, the second stage and the third stage respectively; and
outputting a result of estimation.

2. The estimation method according to claim 1 , wherein the power battery is a lithium iron phosphate power battery.

3. The estimation method according to claim 1 , wherein in the construction of the whole battery capacity model corresponding to the echelon utilization grades,
a linear curve graph of the SOH of the power battery over a cyclic period is constructed according to a performance attenuation rule of the power battery, wherein the linear curve graph has an abscissa representing the cycle period and an ordinate representing the SOH, an origin of coordinates of the linear curve graph is set as a point B, a position of a maximum value of the ordinate is set as a point A, and a position of the maximum value of the abscissa is set as a point C;
the SOH of an unused power battery is set to decrease from 100% to a value x, wherein the value x is in a range of [0, 1]; the value x corresponds to a point D in the linear curve graph, and a perpendicular originating from the point D intersects with the abscissa at a point E; a used capacity of the power battery is defined as Q X , a whole life cycle capacity of the power battery is defined as Q T , and the capacity utilization rate is defined as η=Q X /Q T ×100%, the used capacity Q X corresponds to a product of an area S trapezoid_ABED enclosed by an trapezoid ABED in the linear curve graph and a rate capacity C 0 of a cell, and the whole life cycle capacity Q T corresponds to a product of an area S ΔABC enclosed by a triangle ABC and the rate capacity C 0 of the cell, as shown in the following formulas:
S ΔDEC =x 2 ·S ΔABC
Q T =C 0 ·S ΔABC
Q X =C 0 ·S trapezoid_ABED =C 0 ·( S ΔABC −S ΔDEC )= C 0 ·S ΔABC (1− x 2 )

η= Q X /Q T ×100%=[ C 0 ·S ΔABC (1− x 2 )]/[ C 0 ·S ΔABC ]×100%=100(1− x 2 )%

a battery service capacity in each SOH interval is calculated according to the formulas and the echelon utilization grades of the power battery,
wherein in the first grade corresponding to an SOH interval from 80% to 100%, a whole practical capacity of the power battery throughout the SOH interval from 80% to 100% accounts for 36% of a whole life cycle capacity; wherein the whole practical capacity of the power battery is a usable capacity of the power battery;
in the second grade corresponding to an SOH interval from 40% to 80%, the whole practical capacity of the power battery throughout the SOH interval from 40% to 80% accounts for 48% of the whole life cycle capacity; and
in the third grade corresponding to an SOH interval from 0% to 40%, the whole practical capacity of the power battery throughout the SOH interval from 0% to 40% accounts for 16% of the whole life cycle capacity.

4. The estimation method according to claim 3 , wherein in the construction of the cost model corresponding to the echelon utilization grades,
in a case of a service cut-off capacity of 80% for an electric automobile, a whole service capacity for the electric automobile throughout an SOH interval from 100% to 80% accounts for 36% of the whole life cycle capacity; and in a case of a service cut-off capacity of 40% for energy storage, a whole service capacity for the energy storage throughout an SOH interval from 80% to 40% accounts for 48% of the whole life cycle capacity, a sum of the whole service capacity for the electric automobile and the whole service capacity for the energy storage accounts for 84% of the whole life cycle capacity, is a capacity Q V with use value and is defined as the whole life cycle high-quality capacity; the whole service capacity for the electric automobile accounts for 3/7 of the high-quality capacity of the whole life cycle high-quality capacity, and the whole service capacity for the energy storage accounts for 4/7 of the whole life cycle high-quality capacity; wherein the whole service capacity for the electric automobile represents a total capacity of the power battery that can be used by the electric automobile, the whole service capacity for the energy storage represents a total capacity of the power battery that can be used by the energy storage;
a cost of the power battery is shared between the electric automobile and the energy storage using the power battery in an SOH interval from 100% to 40%, regardless of a value of recovery and a cost of scrapping of the power battery with the SOH less than 40%;
an echelon utilization grouping rate is γ, and a unit price of the power battery is M,
a theoretical cost Pe Θ to be borne by the electric automobile is expressed using a formula:

Pe
Θ

=

[

3
7

⁢

Q
V

+

4
7

⁢

Q
V

·

(

1
-
γ

)

]

·

M
/

Q
V

=

(

1
-

4
7

⁢
γ

)

Assignees

• State Grid Jiangxi Electric Power Company Limited Res Institute
• State Grid Corp China
• Nanchang Kechen Electric Power Test And Res Co Ltd
• Nanchang Inst Tech

Inventors

• Liu Ping
• Zhang Wenhua
• Xu Rui
• Wu Fayuan
• Deng Yongqiang
• Dai Xiaomin
• Tang Jinhui
• Xiao Hongxia

Classifications

• G06Q10/30

  Administration of product recycling or disposal · CPC title

• G06Q10/087

  Inventory or stock management, e.g. order filling, procurement or balancing against orders · CPC title

• B60L58/16

  responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH] · CPC title

• G01R31/392

  Determining battery ageing or deterioration, e.g. state of health · CPC title

• Y02T10/70

  Energy storage systems for electromobility, e.g. batteries · CPC title