CN114116726A

CN114116726A - SOC-OCV table look-up method for calculating SOC

Info

Publication number: CN114116726A
Application number: CN202111450370.1A
Authority: CN
Inventors: 尚德华; 王嘉兴
Original assignee: Aopu Shanghai New Energy Co Ltd
Current assignee: Aopu Shanghai New Energy Co Ltd
Priority date: 2021-12-01
Filing date: 2021-12-01
Publication date: 2022-03-01

Abstract

The invention discloses an SOC-OCV table look-up method for calculating SOC, which comprises the steps of establishing a one-dimensional array, judging whether an acquired Value is in SOC-OCV or not and finishing the calculation of an SOC Value. The invention has the beneficial effects that: the method comprises the steps that a one-dimensional array SOC-OCV table is established to replace an existing two-dimensional array, when OCV values are collected and then table lookup is carried out, because the values of the arrays are from small to large, an intermediate value comparison method is continuously used, and the table lookup speed is accelerated; the SOC value is obtained by directly using an algorithm formula summarized by research and development and through related OCV values in a table, and if the collected OCV value is not in the OCV table, the SOC value can also be obtained through the formula.

Description

SOC-OCV table look-up method for calculating SOC

Technical Field

The invention relates to a table lookup method, in particular to an SOC-OCV table lookup method for calculating SOC, and belongs to the technical field.

Background

For a battery management system, the most important technical parameter for measuring the whole system is the state of charge (SOC) of a battery, and when the SOC of the battery is calculated, the initial SOC is obtained by acquiring open-circuit voltage (OCV) through a Battery Management System (BMS) and obtaining the OCV through a corresponding relation table of SOC-OCV; however, it takes a long time for the system to look up the corresponding SOC value in the array table by reading the OCV values and then polling one by one.

With the prior art, there are the following disadvantages:

firstly, the OCV value and the OCV value in an SOC-OCV table one by one need to be compared to obtain the SOC value, the comparison is time-consuming, and if the number of the battery cores is too large, when the SOC-OCV table is checked for a plurality of battery cores, the MCU of the BMS cannot process the battery cores due to too large data quantity;

secondly, the prior art needs to establish a two-dimensional array of SOC-OCV, so that the read OCV is in one-to-one correspondence to the corresponding SOC, but if the collected OCV value is not in the OCV of the two-dimensional array of SOC-OCV, the system can only wait for collecting the same OCV value to correspond to the SOC.

Disclosure of Invention

The present invention is directed to solving the above-mentioned problems by providing an SOC-OCV lookup table for calculating SOC.

The invention realizes the purpose through the following technical scheme: a SOC-OCV table look-up method for calculating SOC includes the following steps

Step one, establishing a one-dimensional array, and arranging OCV values from small to large; setting the size of the array as SOC-OCV _ MAX;

judging whether the collected Value is in SOC-OCV or not;

step three, completing the calculation of the SOC value through the following algorithm formula

SOC0＝0+Mid*10+(ocv_soc_Table[Mid]-Value)*10/(ocv_soc_Table[Mid]-ocv_soc_Table[Mid+1])；

Note: 0 of the formula is the corresponding SOC value when OCV is minimum;

step four, End-Frist! When 1, the OCV value is collected between two OCV values of the SOC-OCV table;

note: equation 0 is the corresponding SOC value when OCV is minimum.

As a still further scheme of the invention: in the first step, the introduced parameters include:

the last digit number End of the array (End — SOC-OCV _ MAX-1);

the first digit number Frist (0) of the array;

third, the middle digit number Mid (Mid-End/2) of the array;

the OCV Value collected is Value;

the calculated SOC value is SOC 0.

As a still further scheme of the invention: in the second step, the method specifically comprises the following steps:

built one-dimensional array inside

ocv_soc_Table[0]<＝Value<＝ocv_soc_Table[ocv_soc_MAX-1]

In the case where the above is true,

then when: Mid-End/2 and End-Frist! When 1 is true

If the collected OCV (Value) Value is larger than the Value of the middle bit number of the whole array;

i.e. ocv _ soc _ Table [ Mid ],

because whole OCV array is arranged by little grow, then the OCV correspondence of gathering must be in the array in the back of array median bit number, order promptly:

End＝Mid；Mid＝(End+Frist)/2

otherwise, order:

End＝half；Mid＝(End+Frist)/2。

the invention has the beneficial effects that:

1. the method comprises the steps that a one-dimensional array SOC-OCV table is established to replace an existing two-dimensional array, when OCV values are collected and then table lookup is carried out, because the values of the arrays are from small to large, an intermediate value comparison method is continuously used, and the table lookup speed is accelerated;

2. the SOC value is obtained by directly using an algorithm formula summarized by research and development and through related OCV values in a table, and if the collected OCV value is not in the OCV table, the SOC value can also be obtained through the formula.

Drawings

FIG. 1 is a schematic flow chart of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

Referring to FIG. 1, a SOC-OCV lookup table for calculating SOC includes the following steps

judging whether the collected Value is in SOC-OCV or not;

Note: 0 of the formula is the corresponding SOC value when OCV is minimum;

note: equation 0 is the corresponding SOC value when OCV is minimum.

In the embodiment of the present invention, in the first step, the introduced parameters include:

the last digit number End of the array (End — SOC-OCV _ MAX-1);

the first digit number Frist (0) of the array;

third, the middle digit number Mid (Mid-End/2) of the array;

the OCV Value collected is Value;

the calculated SOC value is SOC 0.

In the embodiment of the present invention, the second step specifically includes:

built one-dimensional array inside

ocv_soc_Table[0]<＝Value<＝ocv_soc_Table[ocv_soc_MAX-1]

In the case where the above is true,

then when: Mid-End/2 and End-Frist! When 1 is true

i.e. ocv _ soc _ Table [ Mid ],

End＝Mid；Mid＝(End+Frist)/2

otherwise, order:

End＝half；Mid＝(End+Frist)/2。

example two

Referring to fig. 1, an SOC-OCV lookup table for calculating SOC includes the following steps:

the method comprises the following steps: establishing an SOC-OCV one-dimensional array table of the lithium iron phosphate battery:

ocv_soc_Table[ocv_soc_MAX]＝{2500,3200,3270,3280,3290,3300,3320,3400,3480,3490,3650}

wherein the data set is the value from small to large of OCV value, and the corresponding SOC value is 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100% from small to large;

step two: through the process of the flow chart of the specific scheme, the OCV value acquired by the corresponding BMS system can be assigned to verify the actual effect; through the flow logic and formula algorithm, the corresponding SOC value is calculated, and the assigned OCV and the SOC value obtained by the corresponding system through the patent logic and algorithm formula experiment are as follows:

OCV	2500	3200	3270	3280	3290	3300	3320	3400	3480	3490	3650
												SOC	0	10	20	30	40	50	60	70	80	90	100

simultaneously: some OCV values not in the OCV table were randomly assigned and the results were as follows:

OCV	3000	3250	3275	3284	3296	3329	3450	3485	3600
										SOC	7	17	25	34	46	61	76	85	96

to sum up: actual verification is consistent with theory, and the overall logic and the algorithm formula are established.

The working principle is as follows: establishing a one-dimensional array SOC-OCV table to replace the existing two-dimensional array; when the OCV value is collected and then table lookup is carried out, because the value of the array is from small to large, an intermediate value comparison method is continuously used, and the table lookup speed is accelerated; the SOC value is obtained by directly using an algorithm formula summarized by research and development and through related OCV values in a table, and if the collected OCV value is not in the OCV table, the SOC value can also be obtained through the formula.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. An SOC-OCV lookup table for calculating SOC, comprising: comprises the following steps

judging whether the collected Value is in SOC-OCV or not;

Note: 0 of the formula is the corresponding SOC value when OCV is minimum;

note: equation 0 is the corresponding SOC value when OCV is minimum.

2. The SOC-OCV lookup table for calculating SOC of claim 1, wherein: in the first step, the introduced parameters include:

the last digit number End of the array (End — SOC-OCV _ MAX-1);

the first digit number Frist (0) of the array;

third, the middle digit number Mid (Mid-End/2) of the array;

the OCV Value collected is Value;

the calculated SOC value is SOC 0.

3. The SOC-OCV lookup table for calculating SOC of claim 1, wherein: in the second step, the method specifically comprises the following steps:

built one-dimensional array inside

ocv_soc_Table[0]<＝Value<＝ocv_soc_Table[ocv_soc_MAX-1]

In the case where the above is true,

then when: Mid-End/2 and End-Frist! When the number is equal to 1, the alloy is put into a container,

i.e. ocv _ soc _ Table [ Mid ],

End＝Mid；Mid＝(End+Frist)/2

otherwise, order:

End＝half；Mid＝(End+Frist)/2。