CN102903976B

CN102903976B - A kind of pure electric automobile charging process SOC modification method

Info

Publication number: CN102903976B
Application number: CN201210365260.XA
Authority: CN
Inventors: 刘飞; 文锋; 阮旭松; 田远波
Original assignee: Huizhou Epower Electronics Co Ltd
Current assignee: Huizhou Epower Electronics Co Ltd
Priority date: 2012-09-27
Filing date: 2012-09-27
Publication date: 2015-09-09
Anticipated expiration: 2032-09-27
Also published as: CN102903976A

Abstract

A kind of pure electric automobile charging process SOC modification method, the method comprises charge mode, charging pre-corrected pattern, constant-current charging phase and constant-pressure drop current charge stage.Compared with prior art, tool of the present invention has the following advantages: 1. dump energy estimation is more accurate, in current discharge process dynamic corrections SOC basis on, add that in charging process, SOC revises, and which adds the accuracy of dump energy estimation.2. add battery charge, extend battery, charging is initially revised, and adds charge volume; Lithium ion battery is full of electricity condition and uses, and can extend its useful life.

Description

A kind of pure electric automobile charging process SOC modification method

Technical field

The invention belongs to batteries of electric automobile management domain, the modification method of the SOC specifically in pure electric automobile charging process improves.

Background technology

SOC(and state-of-charge, refer to the ratio of the residual capacity of storage battery and its capacity when being full of electricity condition completely) as the parameter weighing battery pack dump energy, driver is played a very important role, as the dump energy of battery accurately can not be grasped, electric automobile stops in road risk because not having electricity can be caused.In order to weigh the dump energy of battery pack accurately, the battery management system (hereinafter referred to as BMS) of some technological precedences at present adopts the method revising SOC in running car, reaches the object of accurately estimation dump energy.But the fact of battery cell inconsistency objective reality, the cell of some characteristic differences causes battery pack can not be full of completely when charging, and SOC has been shown as 100 according to ceiling voltage monomer, and this will cause SOC to estimate to there is error.

At present in battery management system field, major part is all the estimation according to voltage static state; The technology that some technology are leading, in order to accurately estimate SOC, also just taking dynamic corrections SOC value in running car at present, and not revising in charging process.Due to battery cell inconsistency, cause battery pack to be full of completely, the estimation of such SOC brings error.

Summary of the invention

In view of this, the technical problem to be solved in the present invention is the pure electric automobile charging process SOC modification method that estimation is accurate, adopt dynamic corrections.

In order to solve the problems of the technologies described above, this technical problem adopts following scheme to solve:

A kind of pure electric automobile charging process SOC modification method, the method comprises the steps:

A). enter charge mode, detect cell whether meet simultaneously minimum temperature >=X degree Celsius, charging current >=Y ampere, duration of charge >=Z minute, if meet above-mentioned condition, then enter charging pre-corrected pattern, otherwise enter step c constant-current charging phase;

B). enter charging pre-corrected pattern, according to the scope of the minimum monomer voltage Vmin in battery pack under this pattern, select suitable charging pre-corrected pattern to revise, after correction, enter next step;

C). enter constant-current charging phase, this stage, according to the SOC value obtained in b step, charges with constant electric current, until monomer battery voltage reaches upper voltage limit threshold values;

D). enter the constant-pressure drop current charge stage, this stage charges with constant voltage, the mode that reduces electric current gradually, reduces to till 0, complete charge process until charging current;

E). enter charging end SOC and revise step, if SOC is not equal to 100% during this step, then need SOC to be modified to 100.

Wherein, described charging pre-corrected pattern is:

When minimum monomer voltage Vmin meets 2.5V≤Vmin≤3 V, SOC=10* Vmin-25;

As 3 V < Vmin≤3.2V, SOC=25* Vmin-70;

As 3.2V < Vmin≤3.3V, SOC=200* Vmin-630;

As 3.3V < Vmin < 3.373V, and SOC≤35, then directly SOC is adapted to 30;

As Vmin >=3.373V, and during SOC≤85, directly SOC is adapted to 80.

Compared with prior art, tool of the present invention has the following advantages:

1. dump energy estimation is more accurate, in current discharge process dynamic corrections SOC basis on, add that in charging process, SOC revises, and which adds the accuracy of dump energy estimation.

2. add battery charge, extend battery, charging is initially revised, and adds charge volume; Lithium ion battery is full of electricity condition and uses, and can extend its useful life.

Embodiment

The present invention to be described in further detail below in conjunction with embodiment for the ease of it will be appreciated by those skilled in the art that:

The pure electric automobile charging process SOC modification method that the present embodiment discloses, the method comprises the steps:

Wherein, parameter X value is 15, parameter Y value 4, parameter Z values is 10.In the present embodiment, parameter X, Y, Z determine according to cell characteristic conventional in existing electric automobile, are empirical statistics value, span is generally: X can [13,17] value, as 13 or 17, Y can [3,5] scope value, as 3 or 5, Z can in [8,12] scope value, as 8 or 12, identical goal of the invention can be reached equally.

For C) the constant electric current that adopts of charging in step is according to cell characteristic conventional in existing electric automobile, and its value is generally 1C, and this value is also empirical statistics value.

Determine according to battery cell ceiling voltage higher limit for the constant voltage in d) step, different battery cell value is different, and this value is that battery cell must disclosed parameter when dispatching from the factory, and can directly obtain from each parameter of battery cell that manufacturer provides.For the frequency and the size that reduce electric current in this step gradually, also can determine according to the characteristic of battery cell, this step method is more common in battery charging field, and be prior art, therefore not to repeat here.

Wherein, described charging pre-corrected pattern is:

When minimum monomer voltage Vmin meets 2.5V≤Vmin≤3 V, SOC=10* Vmin-25;

As 3 V < Vmin≤3.2V, SOC=25* Vmin-70;

As 3.2V < Vmin≤3.3V, SOC=200* Vmin-630;

As 3.3V < Vmin < 3.373V, and SOC≤35, then directly SOC is adapted to 30;

As Vmin >=3.373V, and during SOC≤85, directly SOC is adapted to 80.

In practice, the value of SOC is all with percent value, in this programme, in order to formulae discovery is simple, therefore the % of SOC value is removed, and directly adopts simple numerical value.

Above-described embodiment is only wherein specific implementation of the present invention, and it describes comparatively concrete and detailed, but therefore can not be interpreted as the restriction to the scope of the claims of the present invention.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these apparent replacement forms all belong to protection scope of the present invention.

Claims

1. a pure electric automobile charging process SOC modification method, is characterized in that, the method comprises the steps:

A). enter charge mode, detect cell whether meet simultaneously minimum temperature >=X degree Celsius, charging current >=Y ampere, duration of charge >=Z minute, if meet above-mentioned condition, then enter charging pre-corrected pattern, otherwise enter step c constant-current charging phase, above-mentioned X can [13,17] value, above-mentioned Y can in [3,5] scope value, above-mentioned Z can in [8,12] scope value;

C). enter constant-current charging phase, charge with constant electric current, until monomer battery voltage reaches upper voltage limit threshold values;

E). enter charging end SOC and revise step, if SOC is not equal to 100% during this step, then need SOC to be modified to 100;

Described charging pre-corrected pattern is:

When minimum monomer voltage Vmin meets 2.5V≤Vmin≤3 V, SOC=10* Vmin-25;

As 3 V < Vmin≤3.2V, SOC=25* Vmin-70;

As 3.2V < Vmin≤3.3V, SOC=200* Vmin-630;

As 3.3V < Vmin < 3.373V, and SOC≤35, then directly SOC is adapted to 30;

As Vmin >=3.373V, and during SOC≤85, directly SOC is adapted to 80.