WO2015133068A1

WO2015133068A1 - Device for determining battery type and method for determining battery type

Info

Publication number: WO2015133068A1
Application number: PCT/JP2015/000652
Authority: WO
Inventors: 琢磨飯田; 杉江　一宏; 裕行神保
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2014-03-03
Filing date: 2015-02-13
Publication date: 2015-09-11

Abstract

　This device for determining battery type has a sensor unit, a DC internal resistance computation unit, and a type determination unit. The sensor unit detects the terminal voltage and the charge/discharge current of a battery. On the basis of the terminal voltage and the charge/discharge current detected by the sensor unit, the DC internal resistance computation unit calculates the respective DC internal resistance during charging and discharging of the battery. On the basis of the DC internal resistance during charging and the DC internal resistance during discharging which have been computed by the DC internal resistance computation unit, the type determination unit determines the type of battery.

Description

Battery type determination device and battery type determination method

The present invention relates to a battery type determination device and a determination method for determining a battery type.

Vehicles that use the engine as the main power source are equipped with a battery as the power source for the starter motor that starts the engine. As the battery, a lead storage battery is generally used. In recent years, the charge / discharge characteristics of lead-acid batteries have been improved. For this reason, lead-acid batteries are becoming popular as power sources for special electric vehicles such as electric carts or forklifts that are not profitable with expensive lithium ion secondary batteries.

The largest number of troubles with private cars (specifically, the number of times the Japan Automobile Federation has been dispatched) is battery exhaustion and battery performance degradation. In recent years, an idling stop system has been adopted in order to reduce exhaust gas from vehicles using an engine as a main power source. However, the engine cannot be restarted if the remaining capacity of the battery is reduced while the engine is stopped when idling is stopped, and the output required to start the engine cannot be obtained. It is desired to accurately detect the remaining capacity of the battery so that such a battery trouble can be detected and dealt with in advance (see, for example, Patent Document 1).

Therefore, in recent years, it is known to accurately detect the remaining capacity and the deterioration state of a battery using a battery equivalent circuit model that takes into account a fast response portion and a slow response portion of the battery charge / discharge reaction (for example, Patent Documents). 2).

International Publication No. 2008/152875 JP 2012-63251 A

The present invention provides a battery type determination device and a battery type determination method capable of suitably determining a battery type.

The battery type determination device according to the present invention includes a sensor unit, a DC internal resistance calculation unit, and a type determination unit. The sensor unit detects the terminal voltage and charge / discharge current of the battery. The DC internal resistance calculation unit calculates the DC internal resistance during charging and discharging of the battery based on the terminal voltage and the charge / discharge current detected by the sensor unit. The type determining unit determines the type of the battery based on the DC internal resistance during charging and the DC internal resistance during discharging calculated by the DC internal resistance calculating unit.

In the battery type determination method according to the present invention, the battery terminal voltage and the charge / discharge current are detected, and the DC internal resistance at the time of charging and discharging is calculated based on the detected terminal voltage and charge / discharge current, respectively. To do. Then, the battery type is determined based on the calculated DC internal resistance during charging and DC internal resistance during discharging.

According to the present invention, the type of the battery can be suitably determined by a simple system using the DC internal resistance during charging and discharging.

FIG. 1 is a block diagram showing a configuration of a battery type determination apparatus according to an embodiment of the present invention. FIG. 2 is a diagram for explaining an equivalent circuit model of a battery. FIG. 3 is a diagram schematically illustrating respective resistance components during charging and discharging. FIG. 4 is a diagram showing the difference in DC internal resistance during charging and discharging for each type of battery.

Prior to the description of the embodiments of the present invention, problems in conventional detection methods as disclosed in Patent Documents 1 and 2 will be described. In these detection methods, battery replacement is not considered. The characteristics of the battery vary depending on the type. For this reason, when a battery of a different type is attached by mistake, the remaining capacity and the deterioration state cannot be detected accurately.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.

FIG. 1 is a block diagram schematically showing the configuration of a battery type determination device according to an embodiment of the present invention. FIG. 2 is a diagram for explaining an equivalent circuit model of a battery. FIG. 3 is a diagram schematically illustrating respective resistance components during charging and discharging. FIG. 4 is a diagram illustrating changes in terminal voltage and charging / discharging current during charging and discharging of the battery in the idling stop system.

As shown in FIG. 1, the battery type determination device includes a sensor unit 100, a low-pass filter (LPF) 101, a charge / discharge switching determination unit 102, a DC internal resistance calculation unit (DCIR calculation unit) 103, and a type determination. Part 104. The sensor unit 100 is connected to a vehicle battery (not shown). The sensor unit 100 includes a voltage sensor and a current sensor, and measures the terminal voltage V _t0 and the charge / discharge current i _L0 of the battery, respectively.

Here, the battery is a rechargeable secondary battery, typically a lead storage battery, but is not necessarily limited thereto. In particular, since it is used in a vehicle for an idling stop system (ISS), a lead storage battery for ISS is assumed. This lead storage battery for ISS is generally required to have durability of about several years. For example, the battery industry association standard (SBA S 0101) requires durability of about 30,000 cycles or more (capacity of about 3 years or more).

On the other hand, a general lead storage battery which is almost the same size as the lead storage battery for ISS but is not for ISS has a shorter life than the lead storage battery for ISS. For example, a normal lead-acid battery (ordinary product) used for normal engine start has a life of about 1.5 years, or the weight of the normal product is reduced by reducing the active material content for rationalization. An important type low-grade lead-acid battery (low-grade product) has a life of less than one year (for example, about 0.5 years). If such a general lead-acid battery that is not for ISS is accidentally mounted on an ISS vehicle at the time of battery replacement, there is a high possibility that it will not be possible to deal with service inspections such as vehicle inspections conducted annually. It is not desirable to install a general lead storage battery in a vehicle.

The LPF 101 cuts the battery terminal voltage V _t0 and the charge / discharge current i _L0 input from the sensor unit 100 at a frequency determined by a predetermined time constant, and outputs a processing voltage value Vt1 and a processing current value i _L1. To do. Here, the predetermined time constant may be a fixed value, but may be varied according to the state of the battery such as the temperature, the degree of deterioration, and the charging rate of the battery.

The charge / discharge switching determination unit 102, the DCIR calculation unit 103, and the type determination unit 104 are a central processing unit (CPU) that performs arithmetic processing, a memory that stores processing programs, learning data, and the like, and processing results by the CPU. And a random access memory (RAM) for temporarily storing inputted data and the like. The following various processes are performed by these hardware. Further, the charge / discharge switching determination unit 102, the DCIR calculation unit 103, and the type determination unit 104 are typically configured by a single-chip large-scale integrated circuit (LSI) or a circuit board, but are not limited thereto. Instead, they may be composed of separate chips or partially integrated chips.

The charging / discharging switching determination unit 102 determines switching between charging and discharging of the battery based on the terminal voltage V _t0 detected by the sensor unit 100 and the charging / discharging current _iL0 . For example, typically, a large current flows instantaneously from the battery when the engine is started, so that the charge / discharge switching determination unit 102 determines that the amount of change of the charge / discharge current i _L0 per predetermined time is a predetermined threshold Δi. when _Th1 or more, and determines that the amount of change per predetermined time of the terminal voltage V _t0 is switched to a discharge state when at least one of time of more than a predetermined threshold value [Delta] V _Th1. In addition, the charge / discharge switching determination unit 102 typically charges the battery at a constant current and a constant voltage when the vehicle is running, so at least one of the terminal voltage V _t0 and the charge / discharge current i _L0 per predetermined time. When the amount of change is within the range of the predetermined threshold values ΔV _Th2 and Δi _{Th2 and} is equal to or greater than the predetermined threshold values V _Th3 and i _Th3 , respectively, it is determined that the charging state has been switched. In addition, the method of the charging / discharging switching determination by the charging / discharging switching determination unit 102 is not limited to these, and other methods may be used as long as the determination is made using at least one of the terminal voltage V _t0 and the charging / discharging current i _L0 . It may be determined by a technique.

The DCIR calculation unit 103 calculates the DC internal resistance (DCIR) of the battery during charging and discharging using the processing voltage value V _t1 and the processing current value i _L1 input from the LPF 101. For example, the DCIR calculation unit 103 plots two or more time changes of the processing voltage value V _t1 and the processing current value i _L1 and calculates the slope thereof as DCIR. However, the calculation method is not limited to this. Then, the DCIR calculation unit 103 acquires the determination result of the charge / discharge switching determination unit 102, and calculates DCIR as the DCIR of the battery at the time of charging at the time of charging and as the DCIR of the battery at the time of discharging at the time of discharging.

Further, the DCIR calculation unit 103 has a known filter such as an equivalent circuit model of the battery shown in FIG. 2 and a Kalman filter. The input processing voltage value V _t1 and the processing current are input using the equivalent circuit model and the filter. The parameter of the equivalent circuit model is sequentially estimated from the value i _L1 . Battery equivalent circuit model of FIG. 2, the ohmic resistance R ₀ and the reaction resistance which is the sum of the charge transfer resistance R ₁ of the positive and negative electrodes, the resistance component R ₂ and a capacitor component C of the primary of an equivalent circuit showing a diffusion resistance polarization It consists of _two parameters. Means a fast response components and the charge transfer resistance R ₁ of the ohmic resistor R0 and the positive and negative electrodes, first order equivalent circuit means slow response component. Since the fast response component is cut by the LPF 101, the capacitor components of the primary equivalent circuit and the secondary equivalent circuit need not be considered.

Next, the correspondence relationship between the equivalent circuit model of the battery shown in FIG. 2 and the DCIR calculated by the DCIR calculation unit 103 will be described. FIG. 3 is a diagram schematically illustrating respective resistance components during charging and discharging.

As shown in FIG. 3, the ohmic resistance R _{0 —} chg during charging corresponds to the AC internal resistance (ACIR) during charging, and the ohmic resistance R _{0 —} dis during discharging corresponds to the AC internal resistance (ACIR) during discharging. Further, the reaction resistance by the sum of the ohmic resistance R _{0 —} chg at the time of charging and the charge transfer resistance R _{1 —} chg of the positive and negative electrodes is the DC internal resistance (DCIR) at the time of charging, the ohmic resistance R _{0 —} dis at the time of discharging, The reaction resistance based on the sum of the movement resistance R _{1 —} dis corresponds to the direct current internal resistance (DCIR) during discharge. Since R2_chg indicating diffusion resistance polarization during charging and R2_dis indicating diffusion resistance polarization during discharging are resistance components of a slow component, they are not included in DCIR due to a short-time reaction. In this way, by pre-processing the charge / discharge voltage and current with the LPF 101, the fast-response resistance component of the equivalent circuit model can be easily calculated as DCIR incorporating the ohmic resistance and the positive and negative charge transfer resistances.

The type determining unit 104 determines the type of the battery from the DCIR at the time of charging and the DCIR at the time of discharging calculated by the DCIR calculating unit 103. The DCIR during charging and the DCIR during discharging differ depending on the battery. In addition, lead-acid batteries, in particular, have poor charge acceptance, so that the DCIR during charging is higher than the DCIR during discharging when the state of charge (SOC) is high. This is influenced by R _{1 —} chg indicating the reaction resistance of the fast response component. On the other hand, in the lead storage battery for ISS, the charge acceptance is improved as compared with a general lead storage battery, so that the DCIR at the time of charging is lower than the DCIR at the time of charging a general lead storage battery. As a result, R _{1 —} chg indicating the reaction resistance of the fast response component is also smaller than that of a general lead-acid battery.

Using the above relationship, the type determination unit 104 calculates the difference between the DCIR at the time of charging and the DCIR at the time of discharging, and determines whether this difference is equal to or less than a predetermined threshold value. Since the ohmic resistance changes little between charging and discharging (R _{0 —} chg≈R _{0 —} dis), the effect of the ohmic resistance is eliminated by taking the difference between the DCIR during charging and the DCIR during discharging. It can be specified as the difference (R ₁ — chg−R _{1 —} dis) between the reaction resistance at the time and the reaction resistance at the time of discharge. Therefore, if the difference between the reaction resistance during charging and the reaction resistance during discharging (R ₁ — chg−R _{1 —} dis) is greater than a predetermined threshold, the type determination unit 104 has a large reaction resistance R _{1 —} chg during charging, Therefore, it determines with it being not a lead storage battery for ISS but a general lead storage battery. On the other hand, when the difference between the reaction resistance during charging and the reaction resistance during discharging (R ₁ — chg−R _{1 —} dis) is equal to or less than a predetermined threshold, the type determination unit 104 has a small reaction resistance R _{1 —} chg during charging, Therefore, it determines with it being a lead storage battery for ISS.

(Modification)
Based on the above battery model, the difference of the reaction resistance at the time of charge and the reaction resistance at the time of discharge was measured about various batteries. FIG. 4 is a diagram illustrating a difference in DC internal resistance during charging and discharging for each type of battery.

Here, A to E shown on the horizontal axis in FIG. 4 are battery types. The battery A is a lead storage battery for ISS and has a lifetime of at least 3 years. In addition, the batteries B to E are lead storage batteries that are not for ISS use, and the life of the batteries decreases from the batteries B to E. The batteries B and C are relatively high grade products, and have a life of about several years (for example, the battery B has a life of about 2 years and the battery C has a life of about 1.5 years). On the other hand, the batteries B and C are relatively low-grade products and have a lifetime of less than one year (for example, the lifetimes of the battery D and the battery E are about 0.5 years).

The vertical axis in FIG. 4 is a value obtained by normalizing the difference between the reaction resistance during charging and the reaction resistance during discharging in the battery A to a reference value. As shown in FIG. 4, the values on each vertical axis are battery A = 1, battery B = 1.2, battery C = 1.1, battery D = 1.8, and battery E = 1.9. Here, according to the actual measurement value shown in FIG. 4, even if it is a general lead acid battery, a high grade product has a normalization value close to that of an ISS product. Since the battery D and the battery E have a relatively large difference with respect to the battery A, whether or not the battery is an ISS product can be distinguished by setting a rough value of about the first threshold Th1 = 1.5. On the other hand, since the battery B and the battery C are relatively small with respect to the battery A, the first threshold Th1 cannot be distinguished, and it is necessary to set a precise value such as the second threshold Th = 1.05. There is.

Therefore, if the difference between the reaction resistance at the time of charging and the reaction resistance at the time of discharging is larger than a predetermined first threshold value Th1, the type determining unit 104 determines that it is not a lead storage battery for ISS but a general lead storage battery. . For example, it may be determined that the product is a lower grade product. On the other hand, if the difference between the reaction resistance at the time of charging and the reaction resistance at the time of discharging is equal to or less than a predetermined first threshold value Th1, the type determining unit 104 determines that there is a possibility of a lead storage battery for ISS. For example, it may be determined that any one of the high-grade products among the lead storage battery for ISS and the general lead storage battery is included. By setting the first threshold Th1, it is possible to determine and omit an obvious low-grade product that has a relatively large margin with respect to the ISS product and is less affected by manufacturing variations and errors such as measurement. It is possible to prevent undesired loading preferentially and reliably. On the other hand, when it is determined by the first threshold value that there is a possibility of a lead storage battery for ISS, the second threshold value Th2 that is smaller than the first threshold value Th1 is a high-grade product among ISS products and general lead storage batteries. It is possible to determine whether the product is an ISS product with high accuracy.

As described above, according to this embodiment, the type determination unit 104 determines the type of whether or not the battery is for ISS using the difference between the DCIR during charging and the DCIR during discharging. Therefore, in this type determination, as shown in FIG. 2, it is possible to accurately determine the type of the battery while suppressing the processing load and the processing time without using a higher-order equivalent circuit model.

The battery type determination apparatus and the battery type determination method according to the present invention are particularly useful for determining whether or not a lead storage battery used in an idling stop system (ISS) is an appropriate ISS battery.

100 Sensor part 101 Low pass filter (LPF)
102 charge / discharge switching determination unit 103 DCIR calculation unit 104 type determination unit

Claims

A sensor unit for detecting battery terminal voltage and charge / discharge current;
Based on the terminal voltage detected by the sensor unit and the charge / discharge current, a DC internal resistance calculation unit that calculates a DC internal resistance during charging and a DC internal resistance during discharging of the battery;
A type determining unit that determines the type of the battery based on the DC internal resistance at the time of charging and the DC internal resistance at the time of discharging calculated by the DC internal resistance calculating unit;
Battery type determination device.
The type determination unit determines the type of the battery based on the difference between the DC internal resistance at the time of charging and the DC internal resistance at the time of discharging.
The battery type determination device according to claim 1.
The type determination unit determines whether the battery is a lead storage battery for an idling stop system based on the difference,
The battery type determination apparatus according to claim 2.
The type determination unit determines that the battery is not a lead-acid battery for an idling stop system when the difference is greater than a first threshold, and the battery stops idling when the difference is equal to or less than the first threshold. Judge that there is a possibility of lead storage battery for the system,
The battery type determination device according to claim 3.
The type determination unit determines that the battery is a lead-acid battery for an idling stop system when the difference is equal to or smaller than a second threshold smaller than the first threshold, and when the difference is larger than the second threshold, Determining that the battery is not a lead acid battery for an idling stop system;
The battery type determination device according to claim 4.
Based on the terminal voltage detected by the sensor unit and the charge / discharge current, the battery pack further includes a charge / discharge switching determination unit that determines switching between charge and discharge of the battery.
The battery type determination device according to any one of claims 1 to 5.
A filter unit for processing a voltage value and a current value detected by the sensor unit with a low-pass filter;
The DC internal resistance calculation unit uses the determination result of the charge / discharge switching determination unit, the voltage value and the current value processed by the filter unit, and the direct current when the charge / discharge switching determination unit determines that charging is in progress. Calculate the difference between the internal resistance and the DC internal resistance when the charge / discharge switching determination unit determines that it is discharging,
The type determination unit determines that the battery is a lead storage battery for an idling stop system when a calculation result of the DC internal resistance calculation unit is a predetermined threshold value or less.
The battery type determination apparatus according to claim 6.
Detecting battery terminal voltage and charge / discharge current;
Based on the detected terminal voltage and the charging / discharging current, calculating a DC internal resistance during charging and a DC internal resistance during discharging of the battery;
Determining the type of the battery based on the calculated DC internal resistance at the time of charging and the DC internal resistance at the time of discharging,
Battery type determination method.