JP5704014B2 - Secondary battery monitoring device - Google Patents

Description

  The present invention relates to a monitoring apparatus for a secondary battery, and more particularly to a technique for monitoring a deterioration state of a secondary battery.

  When charging / discharging of the secondary battery with a large current (hereinafter, also referred to as “high-rate charging / discharging”) is continued, the internal resistance of the secondary battery may increase temporarily (reversibly). If such a state continues, the deterioration of the secondary battery is promoted (hereinafter, the deterioration of the battery due to the continuation of the high rate charge / discharge is also referred to as “high rate deterioration”). Therefore, it is desirable to accurately grasp whether or not the state of the secondary battery is a state in which high rate deterioration can occur.

  Japanese Patent Application Laid-Open No. 2009-123435 (Patent Document 1) calculates a high-rate deterioration evaluation value for evaluating whether or not the state of a lithium ion secondary battery is a state where high-rate deterioration can occur. A technique for suppressing high rate deterioration using an evaluation value is disclosed. Specifically, in Patent Document 1, a battery deterioration evaluation value is calculated in response to a change in the deviation of the lithium salt concentration in the electrolyte, and the discharge power is determined depending on whether or not the battery deterioration evaluation value exceeds a target value. Is limiting.

  Japanese Patent Laying-Open No. 2010-60406 (Patent Document 2) discloses a technique for estimating the presence or absence of high-rate degradation using a battery model formula given in advance. In this battery model formula, the formula indicating the electrochemical reaction at the electrode (the formula called “Butler-Volmer formula”), the electrode reaction at the surface of the electrode during charge and discharge, the diffusion of lithium in the electrode and in the electrolyte The potential distribution and temperature distribution at each part are modeled. By using this battery model formula, it is possible to obtain the estimated current Im of the battery corresponding to the actually measured battery voltage Vr and the measured temperature Tb. Then, it is estimated that high-rate deterioration has occurred when a deviation occurs between the estimated current Im obtained from the battery model and the actually measured measured current Ir. In the following description, control for estimating information related to the battery such as the estimated current Im and the estimated resistance Rm using the battery model formula described in Patent Document 2 is also referred to as “SOH (State Of Health) control”.

JP 2009-123435 A JP 2010-60406 A

  In the prior art disclosed in the above-mentioned Patent Documents 1 and 2, even if the high-rate deterioration can be detected, the temporary increase amount of the internal resistance of the secondary battery (hereinafter, It cannot be estimated itself (also called “high-rate resistance increase”). For this reason, it is impossible to accurately grasp the deterioration state of the secondary battery, and in the event of a rapid increase in the high-rate resistance, the battery deterioration protection is delayed, or the charge / discharge limit amount is unnecessarily increased. It was.

  The present invention has been made to solve the above-described problems, and an object thereof is to appropriately estimate the amount of increase in the high-rate resistance in the secondary battery.

  The secondary battery monitoring device according to the present invention corresponds to the measurement values of the battery voltage and the battery temperature according to the measurement unit that measures the battery current, the battery voltage, and the battery temperature of the secondary battery, and the battery model that is given in advance A current estimation unit that estimates the battery current; and a high-rate deterioration amount calculation unit that calculates a temporary increase amount of the battery resistance of the secondary battery due to the continuation of charge and discharge of the secondary battery as a high-rate deterioration amount. The high-rate degradation amount calculation unit is Ir, the battery current measurement value is Ir, the battery resistance measurement value obtained from the battery current measurement value and the battery voltage measurement value is Rr, the battery current estimation value estimated according to the battery model is Im, When the estimated value of the battery resistance obtained from the estimated value of the battery current, the measured value of the battery voltage, the measured value of the battery current, and the measured value of the battery temperature is Rm, the high rate deterioration amount is (Im−Ir) / Im × Calculation is performed using one of Rr and (Im−Ir) / Ir × Rm.

  Preferably, the high-rate deterioration amount calculation unit calculates an increase rate of the high-rate deterioration amount using one of (Im−Ir) / Im and (Im−Ir) / Ir.

  A monitoring device for a secondary battery according to another aspect of the present invention includes a measuring unit that measures a battery current, a battery voltage, and a battery temperature of a secondary battery, and a secondary battery that is caused by continuation of charging and discharging of the secondary battery. A high rate deterioration amount calculation unit that calculates a temporary increase amount of the battery resistance as a high rate deterioration amount, and a wear deterioration amount calculation unit that calculates a steady increase amount of the battery resistance due to aging of the secondary battery as a wear deterioration amount; Is provided. The wear deterioration amount calculation unit calculates the measured value of the battery resistance obtained from the battery current and the battery voltage measured after the charge / discharge stop state of the secondary battery continues for a predetermined time or longer as RR1, the initial resistance when the secondary battery is not used. When Rr0 is used, the wear deterioration amount is calculated and stored using the calculation formula of RR1-Rr0. The high-rate deterioration amount calculation unit is LR2 when the measured value of the battery resistance obtained from the battery current and the battery voltage measured in a state where the secondary battery can be charged and discharged is RR2, and the stored wear deterioration amount is ΔRa. The amount is calculated using one of the calculation formulas of RR2-Rr0-ΔRa and RR2-RR1.

  Preferably, the monitoring device further includes a state determination unit that determines that the secondary battery is in the high rate deterioration state when the high rate deterioration amount exceeds a predetermined value.

  Preferably, the monitoring device restricts charging / discharging of the secondary battery when the state determination unit determines that the secondary battery is in the high-rate deterioration state, and when the secondary battery is not determined to be in the high-rate deterioration state, It further includes a charge / discharge control unit that releases the restriction of charge / discharge of the secondary battery.

  Preferably, the monitoring device sets a high rate deterioration evaluation value indicating a degree of deterioration of the secondary battery due to the continuation of charge / discharge of the secondary battery based on the charge / discharge history of the secondary battery to discharge of the secondary battery. In accordance with the comparison result of the evaluation value calculation unit that calculates to change to the discharge side according to the charge of the secondary battery and to change to the charge side according to the charging of the secondary battery, and the high-rate deterioration evaluation value And a factor determination unit for determining whether the factor that increased the high rate deterioration amount is charging or discharging.

  Preferably, when the high-rate deterioration amount increases in a state where one of the charging and discharging of the secondary battery is restricted, the monitoring device is the one in which the factor of the increase in the high-rate deterioration amount is restricted between charging and discharging. And a factor determination unit that determines that it is opposite.

  Preferably, the secondary battery is a lithium ion secondary battery mounted on a vehicle.

  ADVANTAGE OF THE INVENTION According to this invention, the high rate resistance raise amount in a secondary battery can be estimated appropriately.

It is a figure which shows the structure of the vehicle carrying the monitoring apparatus of a secondary battery. It is a figure which shows the structure around a battery. It is a functional block diagram (the 1) of ECU. It is a functional block diagram (the 2) of ECU. It is a figure which shows typically the change of the internal resistance of a battery, and operation | movement of ECU. It is a functional block diagram (the 3) of ECU. It is a flowchart (the 1) which shows the process sequence of ECU. It is a functional block diagram (the 4) of ECU. It is a figure which shows typically the change of high rate resistance raise amount (DELTA) Rh, the battery deterioration evaluation value D, and operation | movement of ECU. It is a functional block diagram (the 5) of ECU. It is a functional block diagram (No. 6) of ECU. It is the figure (the 1) which illustrated the setting method of D upper limit and D lower limit. It is the figure (the 2) which illustrated the setting method of D upper limit and D lower limit. FIG. 6 is a diagram (part 3) illustrating a method for setting a D upper limit value and a D lower limit value; It is a flowchart (the 2) which shows the process sequence of ECU. It is a flowchart (the 3) which shows the process sequence of ECU. It is a flowchart (the 4) which shows the process sequence of ECU. It is a figure which shows the change of high rate resistance raise amount (DELTA) Rh.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a diagram showing the structure of a vehicle equipped with a secondary battery monitoring device according to the present embodiment. The vehicle includes an engine 100, a generator (generator) 200, a PCU (Power Control Unit) 300, a battery (battery) 400, an electric motor (motor) 500, and an ECU (Electronic Control Unit) connected to all of them. 600. The vehicle shown in FIG. 1 is a hybrid vehicle equipped with the engine 100, the generator 200, and the motor 500, but the vehicle to which the present invention can be applied is not limited to the vehicle shown in FIG. 1, and travels using electric power energy. Applicable to all vehicles.

  The power generated by the engine 100 is divided into two paths by the power distribution mechanism 700. One is a path for driving the wheel 900 via the speed reducer 800. The other is a path for generating power by driving the generator 200.

  The power generator 200 generates power using the power of the engine 100 distributed by the power distribution mechanism 700. The power generated by the power generator 200 depends on the operating state of the vehicle and the remaining capacity of the battery 400 (hereinafter simply referred to as “SOC ( Depending on the state of "State Of Charge"), it can be used properly. For example, during normal running or sudden acceleration, the electric power generated by the generator 200 becomes the electric power that drives the motor 500 as it is. On the other hand, when the SOC of battery 400 is lower than a predetermined value, the power generated by generator 200 is converted from AC power to DC power by inverter 302 of PCU 300, and the voltage is adjusted by converter 304. Stored in battery 400.

  The battery 400 is an assembled battery configured by further connecting a plurality of modules in which a plurality of lithium ion secondary battery cells are integrated in series. The positive electrode of the lithium ion secondary battery cell is made of a material (for example, a lithium-containing oxide) capable of reversibly occluding / releasing lithium ions (hereinafter also referred to as “Li salt”). Released and occludes the Li salt in the electrolyte during the discharge process. The negative electrode of the lithium ion secondary battery cell is made of a material (for example, carbon) capable of reversibly occluding / releasing Li salt, occludes Li salt in the electrolyte during the charging process, and converts Li salt into the electrolyte during the discharging process. To release.

  Motor 500 is a three-phase AC motor, and is driven by at least one of the electric power stored in battery 400 and the electric power generated by generator 200. The driving force of the motor 500 is transmitted to the wheel 900 via the speed reducer 800. Thus, the motor 500 assists the engine 100 to cause the vehicle to travel, or causes the vehicle to travel only by the driving force from the motor 500.

  On the other hand, at the time of regenerative braking of the vehicle, the motor 500 is driven by the wheel 900 via the speed reducer 800, and the motor 500 is operated as a generator. As a result, the motor 500 acts as a regenerative brake that converts braking energy into electric power. The electric power generated by the motor 500 is stored in the battery 400 via the inverter 302.

  ECU 600 includes a CPU (Central Processing Unit) and a memory (not shown), and is configured to execute predetermined arithmetic processing based on a map and a program stored in the memory.

  FIG. 2 is a diagram illustrating a structure around the battery 400. As shown in FIG. 2, the battery 400 includes a voltage sensor 601 that detects a voltage across the battery 400, a current sensor 602 that detects a charge / discharge current of the battery 400, and a temperature sensor 603 that detects the temperature of the battery 400. Is provided. Each of these sensors outputs a detection result to ECU 600.

  ECU 600 calculates the charge / discharge power value of battery 400 from the detection value of voltage sensor 601 and the detection value of current sensor 602, and calculates the SOC of battery 400 by integrating the charge / discharge current.

  ECU 600 sets charge power limit value WIN and discharge power limit value WOUT (both in watts) of battery 400, and actual charge power and discharge power respectively set charge power limit value WIN and discharge power limit value WOUT. Control not to exceed.

  In battery 400 according to the present embodiment, when high-rate charging / discharging is continuously performed, the internal resistance may temporarily increase (reversibly), and the output voltage of battery 400 may rapidly decrease. If this state continues, the deterioration of the battery 400 is promoted. The bias of Li salt in the electrolytic solution due to continuous high-rate charge / discharge is considered to be one of the causes of this deterioration.

  Therefore, ECU 600 according to the present embodiment estimates a temporary (reversible) increase amount of internal resistance of battery 400 (hereinafter, also referred to as “high rate resistance increase amount ΔRh”) as continuation of high rate charging / discharging. Then, the high rate deterioration is detected based on the high rate resistance increase amount ΔRh. Specifically, ECU 600 estimates high rate resistance increase amount ΔRh itself determined from the current battery deterioration state, and directly compares estimated high rate resistance increase amount ΔRh with high rate resistance increase amount allowable value ΔRhlim determined from required performance. To improve the detection accuracy of high-rate degradation.

  FIG. 3 is a functional block diagram of ECU 600 according to the present embodiment. Each functional block shown in FIG. 3 may be realized by hardware or software.

  ECU 600 includes acquisition units 610 and 620, a resistance calculation unit 630, an estimation unit 640, and a high-rate resistance increase calculation unit 650.

  Acquisition unit 610 acquires the charge / discharge current of battery 400 detected by current sensor 602. In the following description, the battery charge / discharge current acquired by the acquisition unit 610 is also referred to as “measurement current Ir”.

  Acquisition unit 620 outputs the voltage across battery 400 detected by voltage sensor 601 and the temperature of battery 400 detected by temperature sensor 603. In the following description, the both-end voltage and temperature of the battery 400 acquired by the acquisition unit 620 are also referred to as “measurement voltage Vr” and “measurement temperature Tb”, respectively.

  Resistance calculation unit 630 calculates internal resistance of battery 400 using measurement current Ir and measurement voltage Vr. The resistance calculation unit 630 samples a plurality of correspondence relationships between the measurement voltage Vr and the measurement current Ir, and statistically calculates the internal resistance of the battery 400 (for example, using the least square method) from these sampling values. In the following description, the internal resistance calculated by the resistance calculation unit 630 is also referred to as “measurement resistance Rr”.

  The estimation unit 640 estimates internal parameters related to the battery 400 such as the estimated current Im and the estimated resistance Rm using a battery model that simply models the chemical reaction of the battery 400.

  The estimation unit 640 estimates the charge / discharge current of the battery 400 using a battery model with the measured voltage Vr and the measured temperature Tb as input variables. More specifically, the estimation unit 640 obtains a plurality of internal parameters from the measured current Ir and the measured voltage Vr, and substitutes these internal parameters into a pre-stored battery model, whereby the charge / discharge current of the battery 400 is calculated. presume. In the following description, the charging / discharging current of the battery 400 estimated by the estimation unit 640 using the battery model is also referred to as “estimated current Im”.

  In addition, the estimation unit 640 estimates the internal resistance of the battery 400 using a battery model with the estimated current Im, the measured voltage Vr, the measured current Ir, and the measured temperature Tb as input variables. In the following description, the internal resistance of the battery 400 estimated by the estimation unit 640 using the battery model is also referred to as “estimated resistance Rm”.

  In this battery model, an equation indicating an electrochemical reaction at the electrode of the battery 400 (an equation called “Butler-Volmer equation”), an electrode reaction on the surface of the electrode during charge and discharge, an inside of the electrode, and lithium in the electrolytic solution Various characteristics of chemical reactions occurring in the electrolyte solution of the battery 400 and in the electrode, such as diffusion of potential, potential distribution and temperature distribution in each part, are modeled. The estimated current Im calculated using this battery model reflects the effect of a steady (irreversible) increase in internal resistance (hereinafter also referred to as “abrasion degradation amount ΔRa”) due to aging of the battery 400. However, when the high-rate resistance rises suddenly, the learning speed of the estimated resistance of the battery model cannot catch up, and the influence of the high-rate resistance rise amount ΔRh is not reflected. Therefore, at the time of high rate charge / discharge, a divergence (hereinafter also referred to as “estimated current difference ΔI”) according to the high rate resistance increase ΔRh occurs between the estimated current Im and the measured current Ir. As a specific battery model formula, estimated current Im, and estimated resistance Rm estimation method, for example, the battery model and SOH control described in the above-mentioned Patent Document 2 can be used. In the following description, it is assumed that the estimated current Im and the estimated resistance Rm are calculated using this SOH control. However, the calculation method of the estimated current Im and the estimated resistance Rm is not necessarily limited to this.

  The high rate resistance increase amount calculation unit 650 calculates the high rate resistance increase amount ΔRh using the measurement current Ir, the estimated current Im, and the measurement resistance Rr. Specifically, the high rate resistance increase amount calculation unit 650 pays attention to the point that a divergence corresponding to the high rate resistance increase amount ΔRh occurs between the estimated current Im and the measured current Ir during high rate charge / discharge. 1) The high rate resistance increase amount ΔRh is estimated from 1).

ΔRh = (Im−Ir) / Ir × Rm = (Im−Ir) / Im × Rr = (1-1 / Dh) × Rr (1)
In Formula (1), “Im−Ir” corresponds to the estimated current difference ΔI described above. “Dh” is a battery resistance increase rate, and is a value obtained by Rr / Rm or Im / Ir. (Im−Ir) / Im corresponds to the ratio of the high rate resistance increase ΔRh to the measurement resistance Rr.

Hereinafter, the derivation of Expression (1) will be described in detail.
Whether or not there is an increase in high-rate resistance cannot be determined by conventional SOH control using a battery model. As a result, during high-rate charge / discharge, the estimated current Im obtained by SOH control is larger than the actual measured current Ir. . The deviation width between the estimated current Im and the measured current Ir at the time of high rate charge / discharge increases in accordance with the increase amount of the internal resistance due to the high rate charge / discharge. In this embodiment, paying attention to this point, the high-rate resistance increase amount ΔRh is estimated using the difference between the estimated current Im and the measured current Ir (estimated current difference ΔI).

  The relationship between the estimated value (estimated resistance Rm, estimated current Im) based on the battery model and the actual measured value (measured resistance Rr, measured current Ir) is shown in Expression (1a). In the formula (1a), “ΔV” represents the amount of voltage drop from the open circuit voltage (OCV) of the battery 400.

ΔV = Rm · Im = Rr · Ir (1a)
The deviation width between the estimated current Im and the measured current Ir caused by the increase in the high-rate resistance is defined as the estimated current difference ΔI, and is shown in the formula (1b).

ΔI = Im−Ir (1b)
The estimated current difference ΔI is a positive value during discharging and a negative value during charging.

  The following equation (1c) shows the relationship among the measurement resistance Rr including the high rate resistance increase amount, the reference resistance Rstd not including the high rate resistance increase amount, and the high rate resistance increase amount ΔRh.

ΔRh = Rr−Rstd (1c)
Here, the reference resistance Rstd is a total value (= ΔRa + Rr0) of the wear deterioration amount ΔRa and the new product resistance Rr0. The new resistance Rr0 is an initial resistance when the battery 400 is not used.

  When both sides of the equation (1c) are multiplied by the measurement current Ir and transformed as in the equation (1d), the actual voltage drop amount ΔVhr due to the increase in the high-rate resistance is obtained.

ΔVhr = ΔRh · Ir = (Rr−Rstd) · Ir (1d)
Here, if it is assumed that the estimated resistance Rm does not reflect the effect of the increase in the high-rate resistance and can be ignored, the estimated resistance Rm is equal to the reference resistance Rstd. Therefore, the above equations (1c) and (1d) are Each can be modified into the following (1e) and (1f).

ΔRh = Rr−Rstd = Rr−Rm (1e)
ΔVhr = ΔRh · Ir = (Rr−Rm) · Ir (1f)
Further, when the estimated resistance Rm of the battery model does not change, the influence of the high rate resistance increase is reflected in the estimated current Im. Therefore, the estimated current Im is larger than the measured current Ir that does not include the effect of the high-rate resistance increase. Assuming that the voltage difference based on the difference is the estimated voltage drop amount ΔVhm due to the high-rate resistance rise, the estimated voltage drop amount ΔVhm can be obtained by the following equation (1g).

ΔVhm = Rm · ΔI = Rm · (Im−Ir) (1 g)
Assuming that the estimated voltage drop amount ΔVhm is equal to the actual voltage drop amount ΔVhr as shown in the equation (1a), the equation (1h) is derived from the voltage drop amount ΔVh due to the high-rate resistance rise.

ΔVh = ΔVhm = ΔVhr (1h)
When the expressions (1f) and (1g) are substituted into the expression (1h), the expression (1i) is derived.

ΔVh = Rm · ΔI = ΔRh · Ir (1i)
If the formula (1i) is arranged by the high rate resistance increase amount ΔRh, and the formula (1a) is further substituted and converted from Rm to Rr, the above-described formula (1) can be derived.

  As described above, a method for estimating the high-rate resistance increase ΔRh using the estimated current Im obtained from the battery model has been derived. In addition, Formula (1) can also be arranged by battery resistance increase rate Dh, as shown in Formula (1j). The battery resistance increase rate Dh shown in Expression (1j) is a simple expression indicating the ratio of the high rate resistance increase amount ΔRh included in the measurement resistance Rr.

Dh = Rr / Rm = Im / Ir (1j)
As described above, in the present embodiment, there is a divergence according to the amount of increase in the high-rate resistance between the estimated current Im estimated by the battery model (SOH control) during high-rate charge / discharge and the actually measured measured current Ir ( Paying attention to the point that the estimated current difference ΔI) occurs, the high-rate resistance increase ΔRh is estimated using the estimated current difference ΔI. Therefore, the high rate resistance increase amount ΔRh itself can be estimated with high accuracy.

  In addition, for example, it is possible to determine the presence or absence of high-rate deterioration based on a direct comparison between the current high-rate resistance increase amount ΔRh and the high-rate resistance increase amount allowable value ΔRhlim obtained from the required performance. Therefore, the detection accuracy of high rate degradation can be improved.

  In addition, the high-rate resistance increase amount ΔRh estimation method according to the present embodiment is excellent in that it can be estimated on-board and the calculation load is small while ensuring the estimation accuracy of the high-rate resistance increase amount ΔRh. Yes.

  In the prior art, the high rate resistance increase amount itself could not be accurately estimated. Therefore, there are the following problems. That is, the battery aging degradation profile due to the increase in the high-rate resistance differs depending on the battery, but this point cannot be grasped by the conventional technology. Therefore, when a rapid increase in high-rate resistance occurs, the battery deterioration protection is delayed, and there is a possibility that the battery life cannot be guaranteed. Furthermore, in the prior art, for safety design, it was necessary to set the battery performance of the battery life years as a target value throughout the life from the beginning of use of the battery to the life. For this reason, during a relatively short period of use, the limit amount of charge / discharge is unnecessarily high, resulting in fuel consumption loss. On the other hand, in the present embodiment, as described above, the high rate resistance increase amount ΔRh itself can be estimated with high accuracy, so that the problems of these conventional techniques can be solved.

<Modification of Embodiment 1>
In the first embodiment described above, the high-rate resistance increase amount ΔRh is calculated using the estimated resistance Rm. However, in this modification, the portion using the estimated resistance Rm is simplified.

  FIG. 4 is a functional block diagram of ECU 600 according to this modification. Note that, among the functional blocks shown in FIG. 4, the functional blocks denoted by the same reference numerals as those of the functional blocks shown in FIG. 3 have already been described, and thus detailed description thereof will not be repeated here.

  ECU 600 includes acquisition units 610 and 620, an estimation unit 640, and a high rate resistance increase rate calculation unit 651.

  The high-rate resistance increase rate calculation unit 651 calculates the high-rate resistance increase rate γ from the measured current Ir and the estimated current Im using the equation (2a).

γ = ΔI / Ir = ΔRh / Rm = ΔRh _ny / Rm _ny = Dh−1 (2a)
This formula (2a) is obtained by arranging the formula (1) shown in the first embodiment by the resistance ratio and the current ratio, and setting the high rate resistance increase ΔRh and the estimated resistance Rm as fixed values (for example, degradation of the specified number of years in n years). And later values ΔRh _ny and Rm _ny ).

From this equation (2a), ΔI / Ir is obtained on-board, and the obtained value is compared with an allowable value γlim _ny of the specified number of years as a high-rate resistance increase rate γ to determine the presence or absence of high-rate deterioration. That is, when the formula (2b) is established, it is determined that the high rate deterioration has occurred.

γ = ΔI / Ir = Dh−1 ≧ γlim _ny (2b)
As described above, in this modification, it is possible to determine the presence or absence of high rate deterioration based on whether or not the high rate resistance increase amount ΔRh after the specified number of years exceeds the allowable value without using the estimated resistance Rm.

[Embodiment 2]
In the first embodiment described above, the high rate resistance increase ΔRh is estimated using the estimated current Im estimated according to the battery model.

  On the other hand, in the present embodiment, the high rate resistance increase amount ΔRh is estimated without using the estimated current Im. Specifically, paying attention to the fact that the increase in the high-rate resistance is solved by the diffusion of the Li salt concentration during standing (while charging / discharging is stopped), the measured resistance Rr measured after the standing time necessary for eliminating the high-rate resistance rise is used. The wear deterioration amount ΔRa is estimated, and the estimated wear deterioration amount ΔRa is stored (learned). Then, during running (during charging / discharging), the high rate resistance increase amount ΔRh is estimated using the stored wear deterioration amount ΔRa.

  FIG. 5 is a diagram schematically showing a change in the internal resistance of battery 400 and the operation of ECU 600 according to the present embodiment.

  The internal resistance of the battery 400 includes a new resistance Rr0, a wear deterioration amount ΔRa that increases irreversibly according to aging (the number of years of use), and a high-rate resistance increase that temporarily (reversibly) increases during high-rate charge / discharge A quantity ΔRh may be included. That is, the relationship of Formula (3a) is established.

Internal resistance (= measurement resistance Rr) = Rr0 + ΔR = Rr0 + ΔRa + ΔRh (3a)
In the equation (3a), “ΔR” is an internal resistance increase amount from the new resistance Rr0, and is a total value of the wear deterioration amount ΔRa and the high rate resistance increase amount ΔRh.

  The new resistance Rr0 does not change, and the wear deterioration amount ΔRa also increases gradually according to the years of use, does not increase rapidly, and does not decrease once it increases. On the other hand, the high rate resistance increase amount ΔRh increases at the time of high rate charge / discharge, but gradually decreases as the Li salt concentration diffuses with time after the high rate charge / discharge stop.

  In FIG. 5, before time t1, the vehicle is running (charging / discharging), and the internal resistance includes a new resistance Rr0, a wear deterioration amount ΔRa, and a high rate resistance increase amount ΔRh. In this state, ECU 600 prohibits learning of wear deterioration amount ΔRa.

  After time t1, charging / discharging is stopped, the high-rate resistance increase is gradually eliminated, and the high-rate resistance increase amount ΔRh decreases. At the time t2 when the high-rate resistance increase elimination time T1 has elapsed from the time t1, the high-rate resistance increase amount ΔRh becomes 0, and the high-rate resistance increase is completely eliminated, so the relationship of Expression (3b) is established.

Internal resistance (= measurement resistance Rr) = Rr0 + ΔRa (3b)
ECU 600 permits learning of wear deterioration amount ΔRa at time t2.

  When the vehicle travel is resumed at the subsequent time t3, the ECU 600 is permitted to learn the wear deterioration amount ΔRa, and therefore the measured resistance Rr measured up to the time t4 when the learning permission time T2 elapses is expressed as “measurement resistance. RR1 ”, and a value obtained by subtracting the new resistance Rr0 from the measured resistance RR1 is calculated as the wear deterioration amount ΔRa and stored (learned). That is, the learning value of the wear deterioration amount ΔRa is calculated by Expression (3c).

ΔRa = RR1-Rr0 (3c)
Then, ECU 600 obtains measurement resistance Rr measured during vehicle travel after time t4 as “measurement resistance RR2”, and uses the value obtained by subtracting the learned value of wear deterioration amount ΔRa from measurement resistance RR2 as the high rate resistance increase amount ΔRh. Calculate as

  FIG. 6 is a functional block diagram of ECU 600 according to the present embodiment. Of the functional blocks shown in FIG. 6, the functional blocks denoted by the same reference numerals as those of the functional blocks shown in FIG. 3 have already been described, and thus detailed description thereof will not be repeated here.

  ECU 600 includes acquisition units 610 and 620, resistance calculation unit 630, learning unit 660, and subtraction units 664 and 665.

  The learning unit 660 performs learning control of the wear deterioration amount ΔRa. The learning unit 660 includes a time measurement unit 661, an estimation unit 662, and a storage unit 663.

  The time measuring unit 661 measures the leaving time τ. In the present embodiment, “leaving” means a state in which charging / discharging of the battery 400 is stopped, and is equivalent to the state of the vehicle being in a READY-OFF state (a vehicle cannot travel state). Therefore, the “leaving time τ” is an elapsed time from the time when the vehicle state is switched to the READY-OFF state (time t1 in FIG. 5). The time measuring unit 661 stops measuring the leaving time τ when the vehicle state is switched from the READY-OFF state to the READY-ON state (travelable state) (time t3 in FIG. 5), and the measured leaving time is measured. τ is output to the estimation unit 662.

  When the vehicle state is switched from the READY-OFF state to the READY-ON state, the estimation unit 662 determines whether or not the leaving time τ exceeds the high-rate resistance increase elimination time T1. The high-rate resistance increase elimination time T1 is defined in advance by experiments, for example. When the leaving time τ does not exceed the high rate resistance increase elimination time T1, the estimation unit 662 prohibits learning of the wear deterioration amount ΔRa. When the leaving time τ exceeds the high-rate resistance increase elimination time T1, the estimation unit 662 starts from the time when the READY-ON state is switched to the time when the learning permission time T2 elapses (from time t3 to time t4 in FIG. 5). ) Permits learning of the wear deterioration amount ΔRa, assuming that high-rate charge / discharge is not performed.

  When learning of the wear deterioration amount ΔRa is permitted, the estimation unit 662 acquires the measurement resistance Rr measured until the learning permission time T2 elapses as “measurement resistance RR1”. Focusing on the fact that the measurement resistance RR1 does not include the high-rate resistance increase amount ΔRh, the estimation unit 662 estimates the wear deterioration amount ΔRa using the measurement resistance RR1 by the above-described equation (3c).

  The storage unit 663 stores the estimated wear deterioration amount ΔRa. At this time, the wear deterioration amount ΔRa may be mapped and stored using the measured temperature Tb, SOC, or the like as parameters. The wear deterioration amount ΔRa stored in the storage unit 663 is a learned value of the wear deterioration amount ΔRa.

  FIG. 7 is a flowchart showing a processing procedure of ECU 600 for realizing the function of learning unit 660 described above. Each step of the flowchart shown below (hereinafter, step is abbreviated as “S”) may be realized by hardware as described above, or may be realized by software.

  In S10, ECU 600 determines whether or not it is left standing (while charging and discharging are stopped). If not discharging (NO in S10), ECU 600 moves the process to S15.

  If left unattended (YES at S10), ECU 600 starts or continues to measure the unattended time τ at S11. In subsequent S12, ECU 600 determines whether or not leaving time τ exceeds high-rate resistance increase elimination time T1.

  When leaving time τ exceeds high-rate resistance increase elimination time T1 (YES in S12), ECU 600 permits learning of wear deterioration amount ΔRa in S13. When the leaving time τ does not exceed the high-rate resistance increase elimination time T1 (NO in S12), ECU 600 prohibits learning of the wear deterioration amount ΔRa in S14.

  In S15, ECU 600 determines whether or not a READY-ON state (chargeable / dischargeable state) has been reached. If not in the READY-ON state (NO in S15), ECU 600 ends the process.

  When the state is READY-ON (YES in S15), ECU 600 determines in S16 whether learning of wear deterioration amount ΔRa is permitted. When learning of wear deterioration amount ΔRa is prohibited (NO in S16), ECU 600 ends the process.

  If learning of wear deterioration amount ΔRa is permitted (YES in S16), ECU 600 determines the above-described measurement resistance until at least learning permission time T2 elapses in S17 (before high-rate charge / discharge is started). RR1 is acquired, the wear deterioration amount ΔRa is estimated as RR1-Rr0 in S18, and the wear deterioration amount ΔRa estimated in S19 is stored in the memory.

  Returning to FIG. 6, the subtraction units 664 and 665 will be described. The subtraction unit 664 acquires the measurement resistance Rr as “measurement resistance RR2” in the READY-ON state (chargeable / dischargeable state), and calculates a value (= RR2−Rr0) obtained by subtracting the new resistance Rr0 from the measurement resistance RR2. The calculation result is output to the subtraction unit 665.

  In the READY-ON state, the subtraction unit 665 subtracts the value obtained by subtracting the learning value of the wear deterioration amount ΔRa stored in the memory from the value (= RR2−Rr0) output from the subtraction unit 664, and increases the high rate resistance increase amount ΔRh. Output as. That is, the high rate resistance increase amount ΔRh is calculated by the equation (3d).

ΔRh = RR2-Rr0-ΔRa (3d)
Note that the above-described measurement resistance RR1 may be stored, and the high-rate resistance increase ΔRh may be calculated by the equation (3c).

ΔRh = RR2-RR1 (3e)
As described above, in this embodiment, paying attention to the point that the high-rate resistance rise is eliminated by leaving the battery sufficiently after stopping charging / discharging, and switching to READY-ON again after starting (after READY-OFF). When the standing time τ exceeds the high-rate resistance rise elimination time T1, the amount of wear deterioration is measured using the measurement resistor RR1 in which the high-rate resistance rise is eliminated and new high-rate charge / discharge is not performed. Learn ΔRa. Therefore, the wear deterioration amount ΔRa can be learned with high accuracy. Then, a value obtained by subtracting the learned value of the wear deterioration amount ΔRa from the measured resistance RR2 during traveling (during charging / discharging) is estimated as the high rate resistance increase amount ΔRh. Therefore, the estimation accuracy of the high rate resistance increase amount ΔRh is also improved.

  In this embodiment, since the calculation capacity is small and the calculation load is low, the wear deterioration amount ΔRa and the high rate resistance increase amount ΔRh can be estimated easily and inexpensively even on-board.

<Modification of Embodiment 2>
In the above-described second embodiment, it is assumed that the high rate resistance increase amount ΔRh has been eliminated at the start-up after being left, and the wear deterioration amount ΔRa is learned from the measurement resistance Rr at the start-up, and the learned value of the wear deterioration amount ΔRa is obtained. Was used to estimate the high rate resistance increase ΔRh.

  On the other hand, in this modification, using the difference between the estimated current Im0 obtained from the internal parameter of the battery model (SOH control) when the high-rate resistance rise is eliminated and the estimated current Im obtained from the current internal parameter, A high rate resistance increase amount ΔRh is estimated.

  FIG. 8 is a functional block diagram of ECU 600 according to the present embodiment. Note that, among the functional blocks shown in FIG. 8, the functional blocks denoted by the same reference numerals as the functional blocks shown in FIG. 3 described above have already been described, and thus detailed description thereof will not be repeated.

  ECU 600 includes an acquisition unit 620, estimation units 640A and 640B, and a high rate resistance increase calculation unit 650A.

  The estimation units 640A and 640B are both functionally the same as the estimation unit 640 shown in FIG. However, the estimation units 640A and 640B have different internal parameters used for calculating the estimated current Im. Specifically, estimation unit 640A calculates estimated current Im0 using the internal parameter stored when the high rate resistance increase amount ΔRh is eliminated. Therefore, the estimated current Im0 calculated by the estimation unit 640A does not include the influence of the high rate resistance increase. On the other hand, the estimation unit 640B calculates the estimated current Im using the current internal parameter. Therefore, the estimated current Im calculated by the estimation unit 640B can include the influence of the high rate resistance increase.

  The high-rate resistance increase amount calculation unit 650A estimates the high-rate resistance increase amount ΔRh using the following formula ().

ΔRh = (Im−Im0) / Im × Rr (4)
As described above, in the present modification, the current high-rate resistance increase ΔRh is calculated using the difference between the estimated current Im0 obtained from the internal parameter when the high-rate resistance rise is eliminated and the estimated current Im obtained from the current internal parameter. presume. Therefore, as in the second embodiment, the estimation accuracy of the high rate resistance increase amount ΔRh is improved, and the high rate resistance increase amount ΔRh can be estimated easily and inexpensively even on-board.

[Embodiment 3]
In the present embodiment, a high-rate degradation state is accurately determined using the high-rate resistance increase amount ΔRh accurately estimated in the first and second embodiments, and high-rate degradation is appropriately suppressed.

  In the present embodiment, by combining high-rate deterioration determination using high-rate resistance increase amount ΔRh and high-rate deterioration suppression using battery deterioration evaluation value D, charging / discharging of battery 400 is suppressed according to the high-rate deterioration state. Select the amount variably.

  First, the battery deterioration evaluation value D will be described. ECU 600 sets battery deterioration evaluation value D in accordance with a change in the deviation of the Li salt concentration in the electrolyte solution of battery 400. The ECU 600 changes the battery deterioration evaluation value D to the discharge deterioration side as the deviation of the Li salt concentration in the electrolytic solution increases on the discharge side with a predetermined reference value (“0” in FIG. 9 described later) as the center. The battery deterioration evaluation value D is changed to the charge deterioration side as the deviation of the Li salt concentration in the liquid is larger on the charge side. As a specific method for calculating the battery deterioration evaluation value D, for example, a conventional calculation method described in Patent Document 1 described above can be used.

  Next, high rate deterioration determination using the high rate resistance increase amount ΔRh and high rate deterioration suppression using the battery deterioration evaluation value D will be described.

  FIG. 9 schematically shows changes in high rate resistance increase amount ΔRh and battery deterioration evaluation value D and the operation of ECU 600 according to the present embodiment.

  ECU 600 determines “high rate deterioration” when high rate resistance increase amount ΔRh exceeds deterioration amount large threshold value R1 while the vehicle is traveling. In FIG. 9, “high rate deterioration” is determined in the period from time t11 to t12 and time t13 to t14.

  Here, in the case of a battery in which high-rate degradation includes discharge-side degradation and charge-side degradation, high-rate degradation may progress if charging and discharging on the opposite side are suppressed. Therefore, it is desirable to appropriately determine whether the high rate deterioration is due to excessive charge or excessive discharge, and to suppress charging / discharging as a result. However, the high rate resistance increase amount ΔRh increases regardless of high rate discharge or high rate charge. For this reason, the high rate resistance increase amount ΔRh alone cannot be used to determine whether the deterioration is due to high rate charge (charge side deterioration) or the deterioration due to high rate discharge (discharge side deterioration).

  Therefore, when ECU 600 determines “high-rate deterioration”, it compares battery deterioration evaluation value D with an excessive discharge threshold and an excessive charge threshold, and whether the high-rate deterioration is “discharge-side deterioration” according to the comparison result. Determine whether it is “deterioration on the charging side”. Specifically, the ECU 600 determines that the battery deterioration evaluation value D exceeds the excessive discharge threshold (in FIG. 9, the battery deterioration evaluation value D is closer to the discharge side allowable value than the excessive discharge threshold). Side degradation ”. If the ECU 600 determines “discharge-side deterioration”, the discharge-side allowable value (hereinafter referred to as “D upper limit value”) of the battery deterioration evaluation value D is gradually reduced from the initial value (closer to the reference value). 9 is reduced so as to approach the reference value “0”). Then, ECU 600 suppresses (limits) the discharge of battery 400 according to the reduction of the D upper limit value. On the other hand, when the battery deterioration evaluation value D exceeds the overcharge threshold (in FIG. 9, when the battery deterioration evaluation value D is closer to the charge side allowable value than the overcharge threshold), the ECU 600 determines that “charge side deterioration”. Is determined. If the ECU 600 determines “deterioration on the charging side”, the charging side allowable value (hereinafter referred to as “D lower limit value”) of the battery deterioration evaluation value D is gradually reduced from the initial value (approaches the reference value). 9 is increased so as to approach the reference value “0”). Then, ECU 600 suppresses charging of battery 400 in accordance with the reduction of the D lower limit value.

  In addition, when the vehicle 600 is traveling, the ECU 600 determines that “the high-rate deterioration is eliminated” when the high-rate resistance increase amount ΔRh is below the deterioration amount small threshold value R2 (R2 <R1). In FIG. 9, it is determined that “high-rate degradation has been eliminated” in a period after time t16.

  When ECU 600 determines that “high-rate deterioration has been eliminated,” ECU 600 gradually increases the D upper limit value and the D lower limit value to the initial value, and gradually releases the suppression of charging and discharging.

  FIG. 10 is a functional block diagram of ECU 600 according to the present embodiment. ECU 600 includes a determination unit 670, a setting unit 671, and a suppression unit 672.

  The determination unit 670 compares the high rate resistance increase amount ΔRh with the large deterioration amount threshold value R1 and the small deterioration amount threshold value R2 while the vehicle is traveling, and determines “high rate deterioration” and “high rate deterioration elimination” based on the comparison result. .

  If the determination unit 670 determines “high rate deterioration”, the battery deterioration evaluation value D is compared with the overdischarge threshold and overcharge threshold, and the high rate deterioration is determined as “discharge side deterioration” according to the comparison result. Or “charging side deterioration” is determined (separated).

  The setting unit 671 sets the D upper limit value and the D lower limit value according to the determination result of the determination unit 670. As described above, the setting unit 671 reduces the D upper limit value (closer to the reference value) when it is “discharge-side deterioration”, and reduces the D lower limit value when it is “charge-side deterioration” (reference value). ).

  12 to 13 are diagrams illustrating a method of variably setting the D upper limit value and the D lower limit value. 12 to 13 typically show only the D upper limit value. As shown in FIG. 12, the D upper limit value may be lowered to the battery deterioration evaluation value D when it is determined as “discharge-side deterioration”. Further, as shown in FIG. 13, the D upper limit value may be decreased stepwise by a fixed step amount. Further, as shown in FIG. 14, a plurality of variable step amounts that are gradually reduced are set with the battery deterioration evaluation value D determined as “discharge-side deterioration” as a target, and step by step with these variable step amounts. You may make it fall to a target.

  Returning to FIG. 10, the suppression unit 672 suppresses charging / discharging of the battery 400 according to the increase / decrease of the D upper limit value and the D lower limit value set by the setting unit 671. The charging power limiting value WIN and the discharging power limiting value WOUT are used for suppressing the charging / discharging. That is, the charging power limit value WIN is narrowed when charging is suppressed, and the discharging power limit value WOUT is narrowed when discharging is suppressed.

  The suppression unit 672 sets the suppression amount of the charge / discharge amount (the squeezing amount of WIN and WOUT) according to the reduction amount of the D upper limit value and the D lower limit value. Thereby, the suppression amount of charging / discharging amount can be variably set according to the D upper limit value and the D lower limit value. And the suppression part 672 restrict | squeezes the charging / discharging amount of the actual battery 400 so that the suppression amount of the set charging / discharging amount may be implement | achieved.

  In the present embodiment, the case where charging / discharging is suppressed using the D upper limit value and the D lower limit value will be described. However, as shown in FIG. 11, the setting unit 671 does not have a function (without using the D upper limit value and the D lower limit value), and the suppression unit 672 directly charges and discharges using the determination result of the determination unit 670. You may make it suppress.

  FIG. 15 is a flowchart showing a processing procedure of ECU 600 for realizing the above-described functions.

  In S20, ECU 600 estimates high rate resistance increase amount ΔRh. As a specific estimation method, the method described in the first and second embodiments may be used.

  In S21, ECU 600 determines whether or not high rate resistance increase amount ΔRh exceeds deterioration amount large threshold value R1.

  When high rate resistance increase amount ΔRh exceeds large deterioration amount threshold value R1 (YES in S21), ECU 600 determines “high rate deterioration” in S22, and in S23 whether the high rate deterioration is the charge side deterioration or the discharge side. A process of determining whether the deterioration has occurred is performed.

  FIG. 16 is a flowchart showing a detailed processing procedure of the high-rate deterioration isolation process (the process of S23 of FIG. 15).

  In S23a, ECU 600 determines whether or not battery deterioration evaluation value D exceeds an excessive discharge threshold. As described above, the battery deterioration evaluation value D changes to the discharge deterioration side as the deviation of the Li salt concentration in the electrolytic solution increases toward the discharge side, and the deviation of the Li salt concentration in the electrolytic solution increases toward the charging side. It is a value that changes to the charging deterioration side. The battery deterioration evaluation value D is calculated separately in other processes.

  In S23b, ECU 600 determines whether or not battery deterioration evaluation value D exceeds an overcharge threshold.

  When battery deterioration evaluation value D exceeds the excessive discharge threshold (YES in S23a), ECU 600 determines “discharge-side deterioration” in S23c.

  When battery deterioration evaluation value D exceeds the overcharge threshold (YES in S23b), ECU 600 determines “charge side deterioration” in S23d.

  When battery deterioration evaluation value D does not exceed the excessive discharge threshold and excessive charge threshold (NO in S23a and NO in S23b), ECU 600 determines that “separation is impossible” in S23e.

  Returning to FIG. 15, ECU 600 determines in S24 whether or not the result of the separation process is “discharge-side deterioration”. In step S25, ECU 600 determines whether the result of the separation process is “deterioration on the charging side”.

  When the result of the separation process is “discharge-side deterioration” (YES in S24), ECU 600 reduces the D upper limit value in S26. If the result of the separation process is “deterioration on the charging side” (YES in S25), ECU 600 reduces the D lower limit value in S27. If the result of the segmentation process is “impossible to segment” (NO in S25), ECU 600 reduces both the D upper limit value and the D lower limit value in S28.

  On the other hand, when high rate resistance increase amount ΔRh does not exceed large deterioration amount threshold value R1 (NO in S21), ECU 600 determines in S29 whether high rate resistance increase amount ΔRh is lower than small deterioration amount threshold value R2. . When high rate resistance increase amount ΔRh does not fall below deterioration amount small threshold value R2 (NO in S29), ECU 600 ends the process.

  When high rate resistance increase amount ΔRh is smaller than deterioration amount small threshold value R2 (YES in S29), ECU 600 determines “high rate deterioration eliminated” in S30, and gradually increases the D upper limit value and the D lower limit value.

  In S31, ECU 600 suppresses (limits) charging / discharging of battery 400 based on the D upper limit value and the D lower limit value. The specific suppression method is as described above.

In step S32, ECU 600 performs re-categorization processing for high rate deterioration.
FIG. 17 is a flowchart showing the processing procedure of the high-rate deterioration re-segmentation process (the process of S32 in FIG. 15).

  In S32a, ECU 600 determines whether or not a predetermined time has elapsed since the start of charge / discharge suppression (the process of S31 in FIG. 15). If the predetermined time has not elapsed (NO in S32a), ECU 600 waits until the predetermined time has elapsed.

  When the predetermined time has elapsed (YES in S32a), ECU 600 determines whether or not the high rate resistance increase amount ΔRh has increased since the start of suppression of charge / discharge in S32b.

  When high rate resistance increase amount ΔRh increases (YES in S32b), ECU 600 determines that the determination result of the previous separation process (the process of S23 in FIG. 15) is incorrect, and makes a determination opposite to the previous separation result. Do. On the other hand, when high rate resistance increase amount ΔRh decreases (NO in S32b), ECU 600 determines that the determination result of the previous separation process is correct, and performs the same determination as the determination result of the previous separation process.

  FIG. 18 is a diagram showing a change in the high rate resistance increase amount ΔRh. As shown in FIG. 18, when the high rate resistance increase amount ΔRh increases in spite of determining the “charge side deterioration” at time t21 and suppressing the charge amount, the ECU 600 causes the “charge side to decrease” at time t22. The previous separation result of “deterioration” is re-determined as “discharge-side deterioration” as the opposite, assuming that it is an error. Thereby, the suppression of the charge amount is stopped and the suppression of the discharge amount is started. As described above, by correcting the previous erroneous determination and appropriately suppressing the charge / discharge, it is possible to prevent the increase in the high-rate resistance due to the charge / discharge suppression on the opposite side due to the erroneous determination.

  As described above, in the present embodiment, by combining the high-rate deterioration determination using the high-rate resistance increase amount ΔRh and the high-rate deterioration suppression using the battery deterioration evaluation value D, the battery can be selected according to the high-rate deterioration state. The charge / discharge suppression amount of 400 is variably selected. Thereby, charging / discharging of the battery 400 can be appropriately suppressed according to the actual amount of increase in the high-rate resistance.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  100 engine, 200 generator, 300 PCU, 302 inverter, 304 converter, 400 battery, 500 motor, 600 ECU, 601 voltage sensor, 602 current sensor, 603 temperature sensor, 610, 620 acquisition unit, 630 resistance calculation unit, 640, 640A , 640B estimation unit, 650, 650A high rate resistance increase calculation unit, 651 high rate resistance increase rate calculation unit, 660 learning unit, 661 time measurement unit, 662 estimation unit, 663 storage unit, 664, 665 subtraction unit, 670 determination unit, 671 Setting part, 672 Suppression part, 700 Power distribution mechanism, 800 Reducer, 900 wheel.

Claims (7)

A secondary battery monitoring device,
A measurement unit for measuring battery current, battery voltage and battery temperature of the secondary battery;
A current estimation unit for estimating the battery current corresponding to the measured values of the battery voltage and the battery temperature according to a battery model given in advance;
A high rate deterioration amount calculation unit that calculates a temporary increase amount of the battery resistance of the secondary battery due to continuation of charge and discharge of the secondary battery as a high rate deterioration amount;
The high-rate degradation amount calculation unit is configured to estimate the measured value of the battery current from Ir, the measured value of the battery resistance obtained from the measured value of the battery current and the measured value of the battery voltage to Rr, and the battery estimated according to the battery model. When the estimated value of current is Im, and the estimated value of the battery resistance obtained from the estimated value of the battery current, the measured value of the battery voltage, the measured value of the battery current, and the measured value of the battery temperature is Rm, The high rate deterioration amount is calculated using one of (Im−Ir) / Im × Rr and (Im−Ir) / Ir × Rm .
The monitoring apparatus further includes a state determination unit that determines that the secondary battery is in a high rate deterioration state when the high rate deterioration amount exceeds a predetermined value . A secondary battery monitoring device,
A measurement unit for measuring battery current, battery voltage and battery temperature of the secondary battery;
A high rate deterioration amount calculation unit for calculating a temporary increase amount of the battery resistance of the secondary battery due to continuation of charge and discharge of the secondary battery as a high rate deterioration amount;
A wear deterioration amount calculation unit that calculates a steady increase amount of the battery resistance due to aging of the secondary battery as a wear deterioration amount;
The wear deterioration amount calculation unit calculates the measured value of the battery resistance obtained from the battery current and the battery voltage measured after the charge / discharge stop state of the secondary battery continues for a predetermined time or more as Rr1, the secondary battery When the initial resistance when not in use is Rr0, the wear deterioration amount is calculated and stored using a calculation formula of Rr1-Rr0,
The high-rate deterioration amount calculation unit Rr2 represents the measured value of the battery resistance obtained from the battery current and the battery voltage measured in a state where the secondary battery can be charged and discharged, and ΔRa represents the stored wear deterioration amount. Then, the high-rate deterioration amount is calculated using a calculation formula of any one of Rr2-Rr0-ΔRa and Rr2-Rr1. The monitoring apparatus for a secondary battery according to claim 2 , further comprising a state determination unit that determines that the secondary battery is in a high-rate deterioration state when the high-rate deterioration amount exceeds a predetermined value. The monitoring device restricts charging / discharging of the secondary battery when the state determination unit determines that the secondary battery is in the high-rate deterioration state, and the secondary battery is in the high-rate deterioration state. The secondary battery monitoring apparatus according to claim 3 , further comprising a charge / discharge control unit that cancels the restriction of charge / discharge of the secondary battery when the determination is not made. The monitoring device
Based on the charge / discharge history of the secondary battery, a high rate deterioration evaluation value indicating the degree of deterioration of the secondary battery due to the continuation of charge / discharge of the secondary battery is discharged according to the discharge of the secondary battery. An evaluation value calculation unit that calculates the change to the charge side according to the charge of the secondary battery,
And a factor determination unit that determines whether the factor of the increase in the high rate degradation amount is charging or discharging according to a comparison result between the high rate degradation evaluation value and the charging side threshold value and the discharging side threshold value. Item 5. The secondary battery monitoring device according to any one of Items 1 to 4 . In the monitoring device, when the high-rate deterioration amount increases in a state where either one of charging and discharging of the secondary battery is restricted, the cause of the increase in the high-rate deterioration amount is restricted among charging and discharging. it further comprising determining factor determination unit that you were opposed to the secondary battery monitoring device according to any one of claims 1-5. The secondary battery is a lithium ion secondary battery mounted on a vehicle, the secondary battery monitoring device according to any one of claims 1-6.

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