KR100444066B1 - Method of correcting state of charge for battery - Google Patents

Abstract

Disclosed is a battery charging state correction method. The disclosed battery charge correcting method includes: (a) determining whether a battery is being charged or discharged; (b) if the battery is being charged in step (a), determining whether a change in charging current is sufficient; (c) when the condition in step (b) is satisfied, ), Voltage( ) And Obtaining (%); (d) if the battery is being discharged in step (a), determining whether a change in discharge current is sufficient; (e) when the condition in step (d) is satisfied, ), Voltage( ) And Obtaining (%); (f) determining whether the value of SOC at charge and SOC at discharge is short enough to be compared; (g) if the condition in step (f) is satisfied, comparing and determining whether the absolute value obtained by subtracting the SOC from the SOC during discharge is greater than the allowable SOC; (h) if the condition in step (g) is met, sending a warning for low current charging or battery maintenance for charging or evenly charging the SOC reset. According to the present invention, there is an advantage that can improve the reliability of the SOC of the battery.

Description

How to calibrate the battery charge {METHOD OF CORRECTING STATE OF CHARGE FOR BATTERY}

The present invention relates to a battery charging state correction method, and more particularly to a battery charge state correction method using a dynamic internal resistance.

One of the general methods of calculating the state of charge (hereinafter, referred to as SOC) is a method of obtaining a high rate discharge capacity (High_rate_Discharge_Ah) from the discharge current amount (Used_Ah) used at time and the discharge current, as shown in Equation 1 below. .

[Equation 1]

The other is obtained by dividing the charge and discharge current amount Iavg used in unit time by the available current amount Ahavail as shown in Equation 2 below.

[Equation 2]

However, in such a battery charge calculation method, if an existing battery charge amount must be kept in memory and a wrong value of a previously stored charge value is input, it may lead to battery failure due to overcharge or deep discharge.

In addition, since hybrid electric vehicles are continuously charged or discharged, the error of the actual SOC value increases, thereby reducing the reliability of the SOC of the battery.

The present invention has been made to solve the above problems, and an object thereof is to provide a method of correcting a state of charge of a battery, which improves reliability of an SOC of a battery and facilitates maintenance of the battery.

1 is a schematic flowchart sequentially showing a method of correcting a battery state of charge according to the present invention;

The battery charge state correction method of the present invention for achieving the above object comprises the steps of: (a) determining whether the battery is being charged or discharged; (b) if the battery is being charged in step (a), determining whether a change in charging current is sufficient; (c) when the condition in step (b) is satisfied, ), Voltage( ) And Obtaining (%); (d) if the battery is being discharged in step (a), determining whether a change in discharge current is sufficient; (e) when the condition in step (d) is satisfied, ), Voltage( ) And Obtaining (%); (f) determining whether the value of SOC at charge and SOC at discharge is short enough to be compared; (g) if the condition in step (f) is satisfied, comparing and determining whether the absolute value obtained by subtracting the SOC from the SOC during discharge is greater than the allowable SOC; (h) if the condition in step (g) is met, sending a warning for low current charging or battery maintenance for charging or evenly charging the SOC reset.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic flowchart schematically showing a method of correcting a battery charge state according to the present invention.

Referring to the drawing, the battery charge state correction method according to the present invention first determines whether the battery is being charged or discharged (step 110).

If the battery is being charged in step 110, it is determined whether the change of the charging current is sufficient (step 120).

When the condition in step 120 is satisfied, internal resistance according to charging ( ), Voltage( ) And (%) Is obtained (step 130).

Subsequently, if the battery is being discharged in step 110, it is determined whether the change of the discharge current is sufficient (step 140).

When the condition in step 140 is satisfied, the internal resistance according to the discharge ( ), Voltage( ) And (%) Is obtained (step 150).

It is determined whether the values of SOC at charge and SOC at discharge are short enough to be compared (step 160).

When the condition in step 160 is satisfied, it is determined whether the absolute value obtained by subtracting the SOC from the SOC during charging is greater than the allowable SOC.

In other words, Compare and judge.

Therefore, the SOC value at the time of charge and the SOC value at the time of discharge are compared with each other. If the value is smaller than SOC_ref (about 15%), the reliability of SOC calculation is recognized.

If the condition in step 170 is satisfied, the SOC reset is sent or a warning for low current charging or battery maintenance for equal charging of the battery is sent.

In step 130, the internal resistance according to the charging ( ), Voltage( ) And (%) Is calculated as follows.

,

,

here, , Is the value at the first charge,

Value at the second charge.

In step 150, the internal resistance according to the discharge ( ), Voltage( ) And (%) Is calculated as follows.

here, Is the value at the first discharge,

Value at the second discharge.

Battery charging state correction method according to the present invention as described above, using the dynamic internal resistance, the charge and discharge using a dynamic internal resistance of a short time comparable to the charge and discharge internal resistance during battery charging or discharging generated during vehicle operation and The discharge SOC is calculated and compared to obtain reliability for the current SOC and to maintain the battery.

In more detail, the hybrid electric vehicle runs while the battery is continuously charged or discharged.

Dynamic internal resistance is calculated by measuring changes in voltage, current, and temperature during charging and discharging (calculating internal resistance and discharging internal resistance as described above for each charging or discharging during a short time). The SOC during discharge is calculated from the SOC during charging according to the resistance.

In addition, the comparison between these two values and the current SOC, and if the error size is larger than the set error value (about 15%), the SOC can be charged to compensate for the SOC, or even battery management such as equal charging and warning. Can increase the reliability.

As described above, the method for correcting the state of charge of a battery according to the present invention has an effect of improving reliability of the SOC of the battery and easily maintaining and maintaining the battery.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent embodiments are possible. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

Claims (3)

(a) determining whether the battery is being charged or discharged; (b) if the battery is being charged in step (a), determining whether a change in charging current is sufficient; (c) when the condition in step (b) is satisfied, ), Voltage( ) And Obtaining (%); (d) if the battery is being discharged in step (a), determining whether a change in discharge current is sufficient; (e) when the condition in step (d) is satisfied, ), Voltage( ) And Obtaining (%); (f) determining whether the value of SOC at charge and SOC at discharge is short enough to be compared; (g) if the condition in step (f) is satisfied, comparing and determining whether the absolute value obtained by subtracting the SOC from the SOC during discharge is greater than the allowable SOC; (h) if the conditions in step (g) are met, charging a SOC reset or sending a warning for low current charging or battery maintenance for equal charging of the battery; Condition correction method. The method of claim 1, In step (c), the internal resistance according to the charging ( ), Voltage( ) And % Is calculated as follows. , , here, Is the value at the first charge, Value at the second charge. The method of claim 1, In the step (e), the internal resistance according to the discharge ( ), Voltage( ) And % Is calculated as follows. here, Is the value at the first discharge, Value at the second discharge.