JP5904916B2 - Battery soundness calculation device and soundness calculation method - Google Patents

Description

  The present invention relates to a battery health level calculation device and a health level calculation method.

For example, in an electric vehicle or a hybrid vehicle, a battery for supplying electric power to an electric motor for driving a vehicle or other electric device is mounted, and the health of the battery is one of parameters for knowing the state of the battery. Need to know the degree of health (SOH). Note that the degree of degradation (SOD: State of Degradation) in relation to SOH is defined as SOD = 1−SOH (.
The following are known as conventional techniques for calculating such soundness or deterioration.

  Patent Document 1 discloses an open-circuit voltage detection unit for a battery, a discharge-current integration unit that integrates the discharge current of the battery, open-circuit voltages at the start and end of integration of the discharge current, an open-circuit voltage and a charge state of the battery A charge state calculation unit that calculates a change in the state of charge during the discharge period from the correlation of the battery, a battery capacity calculation unit that calculates a battery capacity at the time of deterioration from the change in charge state and the integrated discharge current, and a battery capacity at the time of deterioration A deterioration calculating unit that calculates the initial battery capacity deterioration of the battery stored in advance.

  The device described in Patent Document 2 represents a battery as an equivalent circuit composed of an electromotive force, an electrolyte resistance, an electrode resistance combining positive and negative electrodes, and an electrode capacitance. By changing the battery voltage to a low predetermined current value and measuring the battery voltage, the electrolytic solution resistance and the electrode resistance are obtained using approximate equations. The battery life diagnosis is performed using these values.

  Further, the one described in the cited document 3 models the charge / discharge current of the battery and the transfer characteristics from the open circuit voltage to the terminal voltage, and further models the open circuit voltage as a value obtained by multiplying the current integral value by the variable parameter, It comprises a parameter identifier that sequentially identifies each coefficient and variable parameter of the modeled transfer function, and a state estimator that sequentially estimates the charging rate or open circuit voltage as a state quantity. The total capacity is estimated from the ratio of the slope of the open circuit voltage to the charge rate in the estimated charge rate value or the open circuit voltage estimate value and the parameter estimated value.

Japanese Patent Laid-Open No. 2002-243813 JP 2000-133322 A JP 2010-217079 A

However, each of the conventional battery health level calculation apparatuses has the following problems.
That is, in the prior art described in Patent Document 1, it is necessary to increase the amount of change in SOC in order to calculate SOH with high accuracy.
However, when the battery is used for a short time, the amount of change in the SOC is small, and as a result, the SOH cannot be calculated accurately.

In the prior art described in Patent Document 2, the relationship between the parameter of the battery internal resistance equivalent circuit and the battery SOH is used. Since this relationship data determines the calculation accuracy of the SOH, this relationship is used. Data must be determined experimentally beforehand.
However, even if the above relationship is accurately measured, it may be difficult to accurately calculate the parameters of the equivalent circuit by sequential estimation when using an actual battery. If it is only, the soundness estimated value will deviate greatly.

  Furthermore, in the prior art described in Patent Document 3, since the successive estimation is performed using the ratio of the slope of the open-circuit voltage to the charge rate in the charge rate estimated value or the open-circuit voltage estimated value and the parameter estimated value, If the calculation conditions of temperature and SOC change, the estimation accuracy will decrease.

  The present invention has been made paying attention to the above-mentioned problem, and the object of the present invention is to be able to accurately calculate the soundness level of the battery regardless of the length of time from the start of battery use. The object is to provide a soundness calculation device and a soundness calculation method for a battery.

For this purpose, the battery soundness calculation device according to the present invention as set forth in claim 1 comprises:
A voltage sensor for detecting the voltage between the terminals of the battery;
A current sensor for detecting the charge / discharge current of the battery;
A charge / discharge current integrating unit that calculates a charge / discharge current integrated value based on the charge / discharge current detected by the current sensor;
Current calculated from the amount of change in the open-circuit voltage method charge rate calculated from the open-circuit voltage obtained based on the charge / discharge current detected by the current sensor and the terminal voltage detected by the voltage sensor, and the current integrated value obtained from the charge-discharge current integrating unit A first health estimation unit that calculates the first health of the battery from the amount of change in the integration method charging rate;
A second soundness estimation that sequentially estimates the parameters of the battery equivalent circuit model based on the charge / discharge current detected by the current sensor and the terminal voltage detected by the voltage sensor, and estimates the second soundness based on any of the parameters. And
A third soundness calculation unit that calculates a third soundness that is an average value of the first soundness obtained by the first soundness estimation unit and the second soundness obtained by the second soundness estimation unit;
A soundness difference calculating unit that calculates a soundness difference that is a difference between the first soundness obtained by the first soundness estimating unit and the second soundness obtained by the second soundness estimating unit;
A previous value holding unit for storing and holding the previous soundness level;
The weighting average of the third soundness level and the previous soundness level held in the previous value holding unit is weighted with a weight according to the magnitude of the soundness level difference calculated by the soundness level difference calculation unit. A soundness calculation unit that uses the obtained value as the current soundness,
With
The weight is set so that the ratio of the previous soundness to the third soundness increases as the soundness difference increases.
It is characterized by that.

The battery soundness calculation device of the invention according to claim 2 is:
In the battery health level calculation apparatus according to claim 1,
The second soundness is a soundness obtained based on any of the electrolytic circuit resistance, electrode reaction resistance, electrode reaction capacitor capacity, and capacitor capacity representing the open circuit voltage, which are parameters of the equivalent circuit model.
It is characterized by that.

The method for calculating the soundness level of the battery according to claim 3
The charge / discharge current integrated value is calculated based on the charge / discharge current detected by the current sensor,
Current integration method charge rate calculated from the amount of change in the open circuit voltage method charge rate calculated from the open circuit voltage obtained based on the charge / discharge current detected by the current sensor and the terminal voltage detected by the voltage sensor, and the current integrated value of the charge / discharge current The first health level of the battery is calculated from the change amount of
A parameter of the equivalent circuit model of the battery is sequentially estimated based on the charge / discharge current and the terminal voltage, and a second soundness level is estimated based on any of the parameters,
Calculating a third soundness level, which is an average value of the first soundness level and the second soundness level,
Calculate the soundness difference that is the difference between the first soundness and the second soundness,
Remember the previous soundness,
With the weight according to the magnitude of the soundness difference, the value obtained by weighting and averaging the third soundness and the previous soundness as the current soundness,
The weight is set so that the ratio of the previous soundness to the third soundness becomes larger as the soundness difference is larger,
It is characterized by that.

The method for calculating the soundness level of the battery according to the invention of claim 4 includes:
The battery health level calculation method according to claim 3,
The second soundness is a soundness obtained based on any of the electrolytic circuit resistance, electrode reaction resistance, electrode reaction capacitor capacity, and capacitor capacity representing the open circuit voltage, which are parameters of the equivalent circuit model.
It is characterized by that.

  In the battery health level calculating apparatus according to the first aspect of the present invention, the battery health level can be accurately calculated regardless of the length of time from the start of battery use.

  In the battery soundness calculation apparatus according to the second aspect of the present invention, the parameter and the second soundness can be easily estimated.

  In the battery health level calculation method according to the third aspect of the present invention, the battery health level can be accurately calculated regardless of the length of time from the start of battery use.

  In the battery health level calculation method according to the fourth aspect of the present invention, the parameter and the second health level can be easily estimated.

It is a functional block diagram at the time of applying the soundness calculation apparatus of the battery which concerns on Example 1 of this invention to an electric vehicle. FIG. 3 is a functional block diagram of a controller used in the battery health level calculation apparatus according to the first embodiment. It is a figure which shows the equivalent circuit model of the battery used with the controller of FIG. It is a figure which shows the internal resistance (resistance of electrolyte solution) of a battery, and the relationship between soundness. It is a figure which shows the relationship between the internal resistance (electrode reaction resistance) of a battery, and soundness. It is a figure which shows the relationship between the capacitor | condenser capacity of a battery, and soundness. It is a figure which shows the relationship between the soundness error and the ratio of the weighted average. It is a figure which shows the flowchart for the soundness calculation process performed with a controller.

  Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.

First, the overall configuration of the battery health level calculation apparatus according to the first embodiment will be described.
The battery soundness calculation device according to the first embodiment is mounted on an electric vehicle. As shown in FIG. 1, a current sensor 2 for detecting a charge / discharge current i flowing through the battery 1 and each of the components constituting the battery 1 are provided. A voltage sensor 3 for detecting the inter-terminal voltage v of each of the cells 1a to 1n, a temperature sensor 4 for detecting the temperature T of each of the cells 1a to 1n of the battery 1, and a controller 5 comprising a microcomputer, It has.

The battery 1 is connected to a charger 6 for connecting to an external charging facility to charge the battery 1 and a load 7 such as an electric motor for driving the vehicle. The load 7 and the battery 1 can be connected and disconnected with a switch (not shown).
The battery 1 is a rechargeable battery (secondary battery) configured by arranging a large number of cells 1a to 1n in series. For example, a lithium ion battery is used, but the present invention is not limited to this. It goes without saying that other types of batteries such as a hydrogen battery may be used.

The configuration of the controller 5 is shown in FIG.
The controller 5 includes an internal parameter estimator / open-circuit voltage estimator 51, a second soundness estimator 52, a third soundness calculator 53, an open-circuit voltage-charge rate converter 54, and an open-circuit voltage method charge rate change. Amount calculation unit 55, current integration unit 56, current integration method charging rate change amount calculation unit 57, first health level estimation unit 58, health level difference calculation unit 59, health level calculation unit 60, and previous value Holding part 61.
Hereinafter, each of these elements will be described.

The internal parameter estimator / open-circuit voltage estimator 51 receives the charge / discharge current i from the current sensor 2, the terminal voltage v from the voltage sensor 3, and the temperature T from the temperature sensor 4.
The internal parameter estimator / open-circuit voltage estimator 51 has an equivalent circuit model of the battery 1 shown in FIG. In this equivalent circuit model, a capacitor representing the open circuit voltage OCV of the battery 1 and a resistor representing the electrolyte resistance R0 of the battery 1 are connected in series, and the electrode reaction resistance R1 and the capacitor capacitance C1 of the battery 1 are connected to this resistance. A parallel circuit composed of a resistor and a capacitor is connected in series.
The internal parameter estimator / open-circuit voltage estimator 51 uses the Kalman filter (not shown) to determine the internal resistance R0, which is a parameter of the equivalent circuit model, based on the input current i, voltage v, and temperature T. R1, capacitor capacitance C1, and open circuit voltage OCV are estimated sequentially.
Note that the equivalent circuit model of the battery 1 shown in FIG. 3 may use a capacitor capacity C _OCV representing the open circuit voltage instead of the open circuit voltage OCV.

The internal parameter estimator / open-circuit voltage estimator 51 is a second soundness estimator that calculates one of preset internal resistances RO, R1, capacitor capacitance C1, and capacitor capacitance _COCV. In addition to outputting to 52, the calculated open-circuit voltage OCV is output to the open-circuit voltage-charge rate converter 54.

The second soundness level estimation unit 52 obtains a relationship between a parameter corresponding to the parameter input from the internal parameter estimation unit / open-circuit voltage estimation unit 51 and the soundness level in advance by experiment, and stores this data. .
That is, if the input parameter is the resistance R0 of the electrolytic solution, data indicating the relationship between the resistance R0 and the soundness level SOH-R (an example of this is shown in FIG. 4), or the input parameter is the electrode reaction resistance. If it is R1, the relationship between the resistance R1 and the soundness level SOH-R (this example shows the data shown in FIG. 5 or if the input parameter is the capacitor capacitance C1 representing the electrode reaction resistance of the battery 1, Data indicating the relationship between the capacitor capacity C1 and the soundness level SOH-C (an example of this is shown in FIG. 6) is obtained and stored in advance.
4 to 6 are data when the charging rate is 50% and the temperature is 25 ° C., and the second soundness level estimation unit 52 is the data measured when the charging rate and temperature are other than the above. I also remember.

As can be seen from FIGS. 4 to 6, when the deterioration of the battery 1 progresses (the soundness level decreases), the internal resistances R0 and R1 increase and the capacitor capacitance C1 decreases. In the case of the capacitor capacity C _OCV , the same relationship as in the case of FIG. 6 is obtained, and it decreases as the deterioration progresses.
In the second sound level estimation unit 52, in response to either a previously selected from the input parameters R0, R1, C1, C _OCV, its parameters and health of SOH-R, SOH-C, the SOH-C _OCV Refer to the soundness and relationship corresponding to the selected parameters above, and calculate the second soundness (SOH-R, SOH-C, or SOH-C _OCV ) at that time to obtain the third soundness It outputs to the calculation part 53 and the soundness difference calculation part 59.

The third soundness level calculation unit 53 receives the second soundness level (either SOH-R, SOH-C, or SOH-C _OCV ) input from the second soundness level estimation unit 52 and the first soundness level estimation unit 58. The third soundness level SOH-A, which is an average value with the input first soundness level SOH-V, is calculated and output to the soundness level calculation unit 60.

  On the other hand, the open-circuit voltage-charge rate conversion unit 54 previously measured and stored an open-circuit voltage method charge rate SOC-V corresponding to the open-circuit voltage OCV input from the internal parameter estimation unit / open-circuit voltage estimation unit 51. It is determined from the relationship between the open circuit voltage and the charge rate, and is output to the open circuit voltage method charge rate change amount calculation unit 55.

  The open-circuit voltage method charge rate change amount calculation unit 55 calculates the open-circuit voltage method charge rate SOC-V calculated and stored at the start of charge / discharge input from the open-circuit voltage-charge rate conversion unit 54 and the charge / open-circuit voltage method electric power calculated at the present time. A difference from SOC-V, that is, an open-circuit voltage method charging rate change amount ΔSOC-V is calculated and output to the first soundness level estimation unit 58.

  The current integrating unit 56 integrates the charging / discharging current i input from the current sensor 2 from the start of charging / discharging to the present to calculate a current integrated value, and outputs the current integrated value to the current integrating method charging rate change amount calculating unit 57.

  The current integration method charge rate change amount calculation unit 57 divides the current integration value obtained from the start of charge / discharge from the current integration unit 56 to the present by the full capacity of the battery 1 to obtain the current integration charge rate change amount ΔSOC-i. Calculate and output to the first soundness level estimation unit 58.

  The first soundness level estimation unit 58 uses the current integration method charging rate change amount ΔSOC-i input from the current integration method charging rate change amount calculation unit 57 as the open circuit voltage input from the open circuit voltage method charging rate change amount calculation unit 55. The first soundness level SOH-V is calculated by dividing by the voltage method charging rate change amount ΔSOC-V, and is output to the third soundness level calculation unit 53 and the soundness level difference calculation unit 59.

The soundness level difference calculation unit 59 receives the second soundness level (either SOH-R, SOH-C, or SOH-C _OCV ) input from the second soundness level estimation unit 52 and the first soundness level estimation unit 58. The soundness difference ΔSOH, which is the difference between the input first soundness level SOH-V, is calculated and output to the soundness level calculation unit 60.

The soundness calculator 60 includes the third soundness calculator 53 to the third soundness SOH-A, the soundness difference calculator 59 to the soundness difference ΔSOH, and the previous value holder 61 to the previous soundness. SOH (k-1) is input respectively.
The soundness level calculation unit 60 weights the third soundness level SOH-A and the previous soundness level SOH (k-1) according to the magnitude of the soundness level difference ΔSOH, and weights and averages them. Obtain soundness SOH (k).
Details of the weighted average will be described later.
The current soundness level SOH (k) is output to the previous value holding unit 61 of the battery 1.

  The previous value holding unit 61 stores and holds the soundness level SOH (k−1) calculated by the soundness level calculation unit 60 last time. That is, after the soundness calculation unit 60 outputs the current soundness level SOH (k-1) to the soundness calculation unit 60 at the time of calculating the current state, that is, the latest soundness level SOH (k), The calculated soundness level SOH (k) is input, and this value is overwritten on the previous soundness level SOH (k-1) and stored.

Here, the content of the weighted average process executed by the soundness degree calculation unit 60 will be described below.
The second soundness level SOH-R (or SOH-C or SOH-COCV) calculated at the second soundness level 52 based on the parameters in the battery equivalent circuit model, and the first soundness level The difference between the charge rate change amount ΔSOC-V calculated from the open-circuit voltage method charge rate by the estimation unit 58 and the first soundness level SOH-V calculated from the charge amount change amount ΔSOC-i calculated using the current integration method. Since the soundness difference ΔSOH is a difference between soundness levels calculated by different methods, it can be determined that the accuracy of both values is high when the soundness difference ΔSOH is small.
Therefore, in this case, by increasing the weight of the third soundness level SOH-A obtained by averaging the third soundness level calculation unit 53, the latest value newly calculated this time is made larger by the soundness level SOH (k). It can be reflected.

On the other hand, when the soundness difference ΔSOH is larger than a predetermined value, the second soundness level SOH-R (or SOH-C or SOH-COCV) and the first soundness level SOH-V One of them is considered to have high accuracy, while the other is considered to have low accuracy. In this case, it cannot be determined which accuracy is high or low.
Therefore, in such a case, by increasing the weight of the soundness level SOH (k-1) obtained last time, the influence of the low accuracy value calculated this time on the latest soundness level SOH (k) should be excluded. To.

An example of the weighted average ratio with respect to the magnitude of the soundness difference ΔSOH is shown in FIG. Here, it is assumed that the soundness difference ΔSOH and the error used below take absolute values.
As shown in the figure, when the soundness difference ΔSOH is lower than the allowable soundness error, the weight of the previous value SOH (k-1) is set to 0, and the weight of the third soundness SOH-A newly obtained this time Is set to 100% and weighted average processing is performed.
On the other hand, if the soundness difference ΔSOH is higher than the maximum soundness error, the weight of the previous value SOH (k-1) is set to 100%, and the weight of the third soundness SOH-A obtained this time is set to 0. Average processing.
In addition, when the soundness difference ΔSOH is in a range not less than the allowable soundness error and not more than the maximum soundness error, as shown in the figure, as the soundness difference ΔSOH increases, the previous value SOH (k The weight of -1) is increased, for example, in a straight line, and the weight of the third soundness level SOH-A obtained this time is decreased accordingly.
The increase / decrease in the weight is linear in FIG. 7, but may be non-linear.

The above weighted average process is described using mathematical formulas as follows. However, the allowable soundness error is ERSOH-per, and the maximum soundness error is ERSOH-max.
(1) For 0? ΔSOH? ERSOH-per: SOH (k) = SOH-A
(2) In the case of ERSOH-per? ΔSOH? ERSOH-max: SOH (k) = SOH (k-1) x {(ΔSOH-ERSOH-per) / (ERSOC-max-ERSOH-per)} + SOH-A x {1- (ΔSOH-ERSOH-per) ÷ (ERSOC-max-ERSOH-per)}
(3) For ERSOH-max? ΔSOH: SOH (k) = SOH (k-1)

The allowable soundness error ERSOH-per can be determined as follows from the estimation error of the charging rate and the calculation method of the first soundness SOH-V.
In the calculation of the first soundness level SOH-V calculated using the change rate of the charge rate when the estimation error of the charge rate is +/− 3%, the charge rate change amount to be calculated is 70%, and the soundness level is true. If the value is 0.8, it can be calculated as follows.
When the value calculated by the square sum of squares is the allowable soundness error ERSOH-per,
ERSOH-per = 0.8−70 ÷ [70 ÷ 0.8− {3 × 3 + (-3 × -3) ^0.5 }? 0.041
And can be calculated.

The maximum soundness error ERSOH-max can be calculated as follows.
ERSOH-max = 0.8−70 ÷ {70 ÷ 0.8− (3 + 3)} = − 0.0589 → 0.0589 (absolute value)

  Next, soundness calculation processing executed by the controller 5 will be described below based on the flowchart shown in FIG.

As shown in step S1, when the vehicle is turned on and starts running, the controller 5 executes the flowchart shown in FIG.
Next, the process proceeds to step S2.

In step S2, the sensor current that is the charge / discharge current i is read from the current sensor 2, the sensor voltage that is the terminal voltage v from the voltage sensor 3, and the sensor temperature that is the temperature T from the temperature sensor 4 to the controller 5. Is read.
Next, the process proceeds to step S3.

In step S3, the internal parameter estimation unit / open circuit voltage estimation unit 51 sequentially calculates the parameters of the battery 1 and the open circuit voltage OCV sequentially based on the sensor current, sensor voltage, and sensor temperature read in step S2, The open-circuit voltage-charge rate conversion unit 54 calculates the open-circuit voltage method charge rate SOC-V based on the open-circuit voltage OCV.
Next, the process proceeds to step S4.

In step S4, the current integrating unit 56 integrates the charging / discharging current i obtained from the current sensor 2 in step S2 from the start of charging / discharging to the present, and calculates a current integrated value.
Next, the process proceeds to step S5.

In step S5, the current integration method charging rate change amount calculation unit 57 calculates the current integration method charging rate change amount ΔSOC-i by dividing the current integration value obtained in step S4 by the full capacity of the battery 1.
In addition, the open-circuit voltage method charge rate change amount ΔSOC-V is calculated from the difference between the open-circuit voltage method charge rate at the start of charge / discharge obtained in step S3 by the open-circuit voltage method charge rate change amount calculation unit 55 and the current open-circuit voltage method charge rate. Is calculated.
Further, the first soundness level estimation unit 58 divides the current integration method charging rate change amount ΔSOC-i obtained in step S5 by the open circuit voltage method charging rate change amount ΔSOVC-V to obtain the first soundness level SOH-V. Is calculated.
Next, the process proceeds to step S6.

In step S6, the second soundness level estimation unit 52 calculates the second soundness level (here, SOH-R) based on the parameter (for example, one of the internal resistances) obtained in step S3.
Next, the process proceeds to step S7.

In step S7, the soundness difference calculation unit 59 subtracts the first soundness level SOH-V obtained in step S5 from the second soundness level obtained in step S6 (here, SOH-R) to obtain the soundness difference ΔSOH. calculate.
In addition, the third soundness level calculation unit 53 averages the second soundness level (here, SOH-R) obtained in step S6 and the first soundness level SOH-V obtained in step S5 to obtain the third soundness level. Calculate the difference SOH-A.
Next, the process proceeds to step S8.

In step S8, the soundness calculation unit 60 uses the weight according to the size of the soundness difference ΔSOH obtained in step S7, and the soundness SOH (k-1) at the time of the previous run held in the previous value holding unit 61. The weighted average value is calculated by weighting the third soundness level SOH-A obtained in step S8 this time, and this is set as the current soundness level SOH (k).
Next, the process proceeds to step S9.

In step S9, whether or not the controller 5 is charged after the vehicle is stopped based on a vehicle speed signal from a vehicle speed meter (not shown) or an operation position signal of a select lever (not shown) and a charger connection signal from the charger 6. Judging.
If the determination result is YES, the soundness level calculation process is finished, and if NO, the process returns to step ZS2.

As can be seen from the above description, the battery health level calculation device and the health level calculation method of the first embodiment can obtain the following effects.
In the battery soundness calculation device and soundness calculation method according to the first embodiment, the calculation is based on the change amount ΔSOC-V of the open-circuit voltage method SOC-V calculated based on the open-circuit voltage OCV and the charge / discharge current integrated value. The first soundness SOH-V is obtained from the ratio of the change amount ΔSOC-i of the current integration method charging rate SOC-i, and the equivalent circuit of the battery 1 based on the charging / discharging current i, the terminal voltage v, and the temperature T A parameter of the model is estimated by a Kalman filter, and a second soundness level (one of SOH-R, SOH-C, and SOH-C _OCV ) is obtained from the relationship between one of the parameters and the soundness level. The first soundness is weighted according to the magnitude of the soundness difference ΔSOH, which is the difference between the first soundness level SOH-V and the second soundness level (any of SOH-R, SOH-C, or SOH-C _OCV ). Weighted average of degree SOH-V and second degree of health (one of SOH-R, SOH-C, SOH-C _OCV ) and previous degree of health SOH (k-1) In this way, I got the new soundness level SOH (k).
Therefore, the battery health level calculation device and the health level calculation method according to the first embodiment greatly deviate from the estimation accuracy of the health level even if the measurement condition changes for a short time or a long time from the start of charging / discharging. Can be prevented, and the measurement accuracy of the soundness level can be improved.

The parameter for determining the soundness is one of the electrolyte resistance R0, the electrode reaction resistance R1, the electrode reaction capacitor capacity C1, and the capacitor capacity C _OCV representing the open circuit voltage OCV of the equivalent circuit model of the battery 1. Thus, the parameter and the second soundness level can be easily estimated.

  The present invention has been described based on the above embodiments. However, the present invention is not limited to these embodiments, and is included in the present invention even when there is a design change or the like without departing from the gist of the present invention. .

  For example, the battery soundness calculation device of the present invention is applied to an electric vehicle in the first embodiment, but may be applied to a vehicle such as a hybrid vehicle or other devices using a secondary battery.

1 battery
2 Current sensor
3 Voltage sensor
4 Temperature sensor
5 Controller
6 Charger
7 Load
51 Internal parameter estimator / open-circuit voltage estimator
52 Second soundness estimation section
53 Third soundness calculator
54 Open-circuit voltage vs. charge rate calculator
55 Opening voltage method charge rate change calculation part
56 Current integrator
57 Current integration method charge rate change calculation part
58 First soundness calculator
59 Soundness difference calculator
60 Soundness calculator
61 Previous value holding section

Claims (4)

A voltage sensor for detecting the voltage between the terminals of the battery;
A current sensor for detecting a charge / discharge current of the battery;
A charge / discharge current integrating unit that calculates a charge / discharge current integrated value based on the charge / discharge current detected by the current sensor;
From the amount of change in the open-circuit voltage method charging rate calculated from the charging / discharging current detected by the current sensor and the terminal voltage detected by the voltage sensor, and the current integrated value obtained by the charging / discharging current integrating unit A first soundness estimation unit that calculates the first soundness of the battery from the calculated amount of change in the current integration method charging rate;
A parameter of the equivalent circuit model of the battery is sequentially estimated based on the charge / discharge current detected by the current sensor and the terminal voltage detected by the voltage sensor, and a second soundness level is estimated based on one of the parameters. 2 soundness estimation part,
A third soundness calculation unit for calculating a third health of the average of the second soundness obtained by the first sanity and the second sanity estimator obtained by the first sound level estimation unit,
And soundness difference calculation unit for calculating the health index difference is the difference between the second soundness obtained by the first sanity and the second sanity estimator obtained by the first sound level estimation unit,
A previous value holding unit for storing and holding the previous soundness level;
The third soundness calculated by the third soundness calculation unit and the previous soundness held in the previous value holding unit with a weight according to the size of the soundness difference calculated by the soundness difference calculation unit A soundness calculation unit that sets the current soundness as a value obtained by weighting and averaging each degree;
With
The weight is set so that the ratio of the previous soundness to the third soundness becomes larger as the soundness difference is larger,
A device for calculating a soundness level of a battery. In the battery health level calculation apparatus according to claim 1,
The second soundness level is a soundness level obtained based on any one of the electrolyte circuit resistance, electrode reaction resistance, electrode reaction capacitor capacity, and capacitor capacity representing an open circuit voltage, which is a parameter of the equivalent circuit model. A device for calculating the soundness level of a battery. The charge / discharge current integrated value is calculated based on the charge / discharge current detected by the current sensor,
Current integration method calculated from the amount of change in open-circuit voltage method charge rate calculated from the open-circuit voltage obtained based on the charge / discharge current detected by the current sensor and the terminal voltage detected by the voltage sensor and the current integrated value of the charge-discharge current Calculate the first health of the battery from the amount of change in the charging rate,
Sequentially estimating parameters of an equivalent circuit model of the battery based on the charge / discharge current and the terminal voltage, and estimating a second soundness based on any of the parameters;
Calculating a third soundness level which is an average value of the first soundness level and the second soundness level;
Calculating a soundness difference that is a difference between the first soundness and the second soundness;
Remember the previous soundness,
With the weight according to the magnitude of the soundness difference, the value obtained by weighting and averaging the third soundness and the previous soundness as the current soundness,
The weight is set so that the ratio of the previous soundness to the third soundness becomes larger as the soundness difference is larger,
A method for calculating the soundness level of a battery. The battery health level calculation method according to claim 3,
The second soundness is a soundness obtained based on any one of the electrolytic circuit resistance, the electrode reaction resistance, the electrode reaction capacitor capacity, and the capacitor capacity representing the open circuit voltage, which are parameters of the equivalent circuit model.
A method for calculating the soundness level of a battery.

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