JP6790614B2 - Charge / discharge control system for secondary batteries - Google Patents

Description

The present disclosure relates to a charge / discharge control system for a secondary battery, and more particularly to a charge / discharge control system for a secondary battery that is cooled by a cooling means including a filter.

Since the temperature of the secondary battery rises with operation, it is equipped with a cooling means. In Patent Document 1, the amount of foreign matter clogging of the filter used in the temperature control system of the secondary battery mounted on the vehicle is estimated, and when it is determined that the temperature control ability is insufficient, a warning is displayed on a display or the like. Is disclosed.

Here, the amount of foreign matter clogging is estimated based on the amount of air supplied that increases as the rotation speed of the fan increases, the frequency of opening and closing doors and windows, the position of the intake port in the vehicle interior, and the like.

In Patent Document 2, the cooling capacity of the battery cooling device is obtained based on the formula (temperature difference between the battery temperature and the intake air temperature) × (fan air volume) × (correction coefficient), and this cooling capacity and (battery It is disclosed to calculate (estimated battery temperature) based on (calorific value). Then, sequential learning of (correction coefficient for fan air volume) that matches the temperature difference between (actual battery detection temperature) and (estimated battery temperature) is performed, and the target rotation speed of the fan is calculated using the correction coefficient after learning. decide. When the correction coefficient is less than the predetermined value, a warning is displayed on a display or the like.

Japanese Unexamined Patent Publication No. 2014-072182 Japanese Unexamined Patent Publication No. 2013-069470

Even if the cooling performance of the cooling means of the secondary battery deteriorates due to clogging of the filter or the like, the secondary battery continues to be kept at a high temperature until maintenance or the like is performed, which may lead to deterioration of the secondary battery. Therefore, there is a demand for a charge / discharge control system for a secondary battery that can prevent deterioration of the secondary battery when the cooling performance of the cooling means deteriorates.

Discharge control system for a secondary battery according to the present disclosure, a secondary battery, a battery temperature detection means for detecting a temperature of the secondary battery, current detecting means for detecting a battery current flowing through the secondary battery, a secondary cooling means for cooling the next cell, and the intake air temperature detecting means for detecting an intake air temperature is the temperature of the air supplied to the secondary battery by a cooling fan provided in the cooling means, the rotational speed of the cooling fan The rotation speed detecting means for detecting the above , the charge / discharge control device for controlling the charging and discharging of the secondary battery, and the allowable charge / discharge power related file in which the cooling means associates the allowable charge / discharge power with the battery temperature in the normal operating state are stored. A secondary battery charge / discharge control system including a memory connected to the charge / discharge control device , wherein the allowable charge / discharge power-related files have a first threshold in order from the low temperature side to the high temperature side. When the battery temperature is equal to or lower than the first threshold temperature, the absolute value is set to a constant value with respect to the battery temperature at which the temperature, the second threshold temperature, and the target upper limit temperature for protecting the secondary battery from overheating are set, and the battery temperature is the second. In the range from the 1st threshold temperature to the 2nd threshold temperature, the absolute value is gradually reduced from the constant value at the 1st threshold temperature as the battery temperature becomes higher, and + W ₀ or-when the battery temperature is above the 2nd threshold temperature and includes the target upper limit temperature. W is a file allowable discharge electric power is associated to a constant value of _0, the charge and discharge control device, batteries temperature, batteries current, intake air temperature, and, based on the rotation number, cooling means and cooling performance calculating unit cooling performance calculating a, and determines the cooling performance determination unit cooling performance is calculated whether or not a predetermined performance following the cooling performance calculating unit, when cooling performance is less Jo Tokoro performance the batteries temperature determines the battery temperature determination unit that determines whether more than a predetermined temperature, the cooling performance is less than a predetermined performance, and, when the battery temperature is Jo Tokoro temperature above the eye in the allowable discharge power related files to a constant value of + W ₀ or -W ₀ of allowable discharge electric power is set with the target maximum temperature was reduced from + W ₀ or -W ₀ with a decrease in cooling performance, when the cooling performance is zero to include the allowable discharge power changing unit for changing the allowed HiroshiTakashi discharge power to set the allowable discharge electric power to zero, the.

According to the charge / discharge control system for the secondary battery according to the present disclosure, deterioration of the secondary battery can be prevented when the cooling performance of the cooling means deteriorates.

It is a block diagram of the vehicle system which mounts the charge / discharge control system of the secondary battery which concerns on embodiment. This is an example of the allowable charge / discharge power characteristics stored in the memory of FIG. It is a flowchart which shows the procedure of change of the permissible charge / discharge power executed in the charge / discharge control device of the secondary battery which concerns on embodiment. FIG. 3 is a block diagram showing a procedure of a method of calculating the cooling performance of the cooling means. FIG. 3 is a diagram showing an example of changing the allowable charge / discharge power according to the cooling performance. FIG. 5A is a diagram showing an example of an allowable power change relationship map stored in the memory of FIG. 1, and FIGS. 5B, 5C, and 5D are allowable charging / discharging when the cooling performance is different. It is a figure which shows the example of the change of electric power.

The charge / discharge control system for the secondary battery of the embodiment will be described in detail below with reference to the drawings. The numerical values such as temperature described below are examples for explanation, and can be appropriately changed according to the specifications of charge / discharge control of the secondary battery and the like. In the following, similar elements are designated by the same reference numerals in all drawings, and duplicate description will be omitted.

FIG. 1 is a configuration diagram of a vehicle system 10 to which the charge / discharge control system for the secondary battery of the present embodiment is applied. The vehicle system 10 includes a main body 11 and a charge / discharge control device 50 for a secondary battery. The charge / discharge control device 50 controls the operation of the components of the main body 11 as a whole, and in particular, depending on the cooling performance of the cooling device 30 related to the secondary battery 20 included in the main body 11, the secondary battery 20 Change the allowable charge / discharge power. Hereinafter, unless otherwise specified, the charge / discharge control device 50 of the secondary battery is referred to as a control device 50.

The main body 11 includes two rotary electric machines 12 and 13 shown as MG1 and MG2, a power control unit 14 shown as a PCU (abbreviation of Power Control Unit), a secondary battery 20, and a cooling device 30 for the secondary battery 20. ..

The rotary electric machines 12 and 13 and the power control unit 14 correspond to the charge / discharge load of the secondary battery 20. The rotary electric machines 12 and 13 are both motor generators (MGs) mounted on the vehicle, and are three-phase synchronous type that act as an electric motor while the vehicle is running and as a generator while the vehicle is braking. It is a rotary electric machine. The rotary electric machine 12 shown as MG1 is driven by an engine (not shown) and mainly works as a generator, and the rotary electric machine 13 shown as MG2 mainly works as a motor for driving a vehicle. The power control unit 14 includes an inverter circuit connected to the rotary electric machines 12 and 13 and a buck-boost converter provided between the secondary battery 20 and the inverter circuit.

The secondary battery 20 is a high-voltage battery capable of outputting a predetermined high voltage and a large current by combining a plurality of battery cells. An example of the voltage between terminals of the secondary battery 20 is about 200 to 300 V. In FIG. 1, a secondary battery 20 in which a plurality of battery cells are connected in series is shown, but the secondary battery 20 is a combination of series connection and parallel connection as appropriate according to the specifications of high voltage and large current to be output. You can. As the type of battery cell, a lithium ion battery cell, a nickel hydrogen battery cell, or the like is used.

The secondary battery 20 is housed in the battery pack case 22 and cooled by the cooling device 30. The battery temperature detecting unit 24 is a temperature detecting means for detecting the battery temperature θ _B , which is the temperature of the secondary battery 20. The battery current detecting unit 26 is a current detecting means for detecting the discharge current from the secondary battery 20 and the battery current I, which is the charging current from the secondary battery 20. The detected battery temperature θ _B and battery current I data are transmitted to the control device 50 by an appropriate signal line.

The cooling device 30 is a cooling means for cooling the secondary battery 20 with cooling air. The cooling device 30 includes an intake duct 34, a filter 36, and a cooling fan 38 provided between the intake port 32 and the cooling air intake 33 of the battery pack case 22. The air that has entered the intake duct 34 from the intake port 32 passes through the filter 36 and is sent to the battery pack case 22 from the cooling air intake 33 by the cooling fan 38. The cooling air sent into the battery pack case 22 cools the secondary battery 20 and is discharged from the outlet 39. The intake port 32 is provided in the vehicle interior, and the air outlet 39 is arranged in the luggage room. These arrangement positions are examples for explanation and can be appropriately changed according to the specifications of the vehicle.

The filter 36 has a mesh structure and is used for removing dust and the like passing through the intake duct 34. Dust and the like adhere to the network structure of the filter 36 and are trapped. The filter 36 is clogged due to the adhesion of dust and the like, and the cooling performance of the cooling device 30 is deteriorated. When the cooling performance of the cooling device 30 is equal to or lower than a predetermined performance, a notification of filter clogging is displayed on a display or the like in the vehicle interior to prompt the user for maintenance. In maintenance, the filter 36 is removed, the attached dust and the like are removed, or the filter 36 is replaced with a new one. Details such as deterioration of the cooling performance of the cooling device 30 will be described later.

The cooling fan 38 is a fan that operates under the control of the control device 50. In the operating state, the cooling fan 38 sucks the air in the vehicle interior from the intake port 32 and sends it to the battery pack case 22.

The intake air temperature detecting unit 40 is a temperature detecting means for detecting the intake air temperature θ _A , which is the temperature of the air supplied to the filter 36 through the intake port 32. The fan rotation speed detecting unit 42 is a rotation speed detecting means for detecting the fan rotation speed N, which is the rotation speed of the cooling fan 38. The detected data of the intake air temperature θ _A and the fan rotation speed N are transmitted to the control device 50 via an appropriate signal line.

The memory 60 connected to the control device 50 is a memory that communicates with the control device 50 and stores programs used in the control device 50, data for arithmetic processing, and the like. In particular, the allowable charge / discharge power-related file 62 and the allowable power change-related file 64 related to the secondary battery 20 are stored.

FIG. 2 is a diagram showing an example of the allowable charge / discharge power related file 62. The allowable charge / discharge power-related file 62 is a map showing the allowable charge / discharge power of the secondary battery 20 with respect to the battery temperature θ _B. The horizontal axis is the battery temperature θ _B of the secondary battery 20, the positive side of the vertical axis is the allowable discharge power W _OUT related to the discharge power of the secondary battery 20, and the negative side of the vertical axis is the charging power of the secondary battery 20. the allowable charging power W _iN on. The allowable discharge power characteristics 70, 71, 72 and the allowable charge power characteristics 80, 81, 82 of the secondary battery 20 are shown by solid lines, respectively. The horizontal axis shows the battery temperatures θ _B0 , θ _B1 , and θ _{B 2} .

The battery temperature θ _B0 is a target upper limit temperature at which the secondary battery 20 is desired to be protected from overheating. θ _B1 and θ _B2 are two threshold temperatures provided on the lower temperature side than the battery temperature θ _B0 to protect the secondary battery 20. When θ _B0 , θ _B1 , and θ _B2 are distinguished and called the target upper limit temperature θ _B0 , the first threshold temperature θ _B1 , and the second threshold temperature θ _B2 , the first threshold temperature θ _B1 <second threshold temperature θ _B2 <target The upper limit temperature is θ _B0 . The permissible discharge power W _OUT is a permissible discharge power characteristic 70 of a constant value in the range of the battery temperature θ _B equal to or less than the first threshold temperature θ _B1 . When the battery temperature θ _B is in the range of the first threshold temperature θ _B1 to the second threshold temperature θ _B2 , the allowable discharge power characteristic 71 is such that W _OUT gradually decreases as the battery temperature θ _B becomes higher. When the battery temperature θ _B is equal to or higher than the second threshold temperature θ _B2 , the permissible discharge power characteristic 72 has a constant value. Since tolerance is the same for charging power W _IN, omitted details regarding allowable charging power characteristic 80, 81, 82 described.

When the battery temperature θ _B is equal to or higher than the second threshold temperature θ _B2 , the permissible discharge power W _OUT and the permissible charge power W _IN can be set to zero, but in that case, for example, the running performance immediately after the engine is started in a hot region. It will affect you. In FIG. 2, in consideration of running performance in a hot region, the allowable discharge power W _OUT and the allowable charge power _WIN are not set to zero at the second threshold temperature θ _B2 or higher, and the predetermined values of + W ₀ and −W are shown, respectively. _Set to ₀ . The predetermined values of + W ₀ and −W ₀ indicate the allowable discharge power and the allowable charge power at the target upper limit temperature θ _{B 0} , respectively.

A map as shown in FIG. 2 can be obtained in advance by simulation or experiment for the secondary battery 20. In FIG. 2, the allowable charge / discharge powers W _OUT and _WIN are shown in the map format as the allowable charge / discharge power related file 62, but in addition to this, the lookup table format, the mathematical formula relation, and the battery temperature θ _B are input. A ROM format in which W _OUT and W _{IN at} that temperature are output may be used.

By setting the permissible discharge power characteristics 70, 71, 72 and the permissible charge power characteristics 80, 81, 82, the battery temperature θ _B of the secondary battery 20 is targeted while the cooling device 30 has a predetermined cooling performance. The upper limit temperature θ _B0 is almost never exceeded. Cooling device 30, when it has a cooling performance that exceeds a predetermined performance, the battery temperature theta _B be temporarily exceeds the target upper limit temperature theta _B0, quickly returns to the target upper limit temperature theta _B0 following battery temperature theta _B. Lifetime of the secondary battery 20, so determined by the time that is exposed to high temperatures, even the battery temperature theta _B exceeds the target upper limit temperature theta _B0 temporarily no problem battery life.

The permissible power change-related file 64 is the permissible charge / discharge power-related file 62 specified in the permissible charge / discharge power-related file 62 so that the battery temperature θ _B does not exceed the target upper limit temperature θ _{B 0} when the cooling performance of the cooling device 30 is equal to or lower than the predetermined performance. This is a file related to changing the charge / discharge power. The details of the contents will be described later with reference to FIG.

The control device 50 is a device that controls the operation of each element of the main body 11 as a whole, and in particular, changes the allowable charge / discharge power of the secondary battery 20 according to the cooling performance of the cooling device 30. The control device 50 includes a cooling performance calculation unit 52 that calculates the cooling performance of the cooling device 30, a cooling performance determination unit 54 that determines whether the cooling performance is equal to or lower than the predetermined performance, and a determination unit that determines whether the battery temperature is equal to or higher than the predetermined temperature. The battery temperature determination unit 56 is included. The control device 50 further includes a permissible charge / discharge power changing unit 58 that changes the permissible charge / discharge power.

These functions of the control device 50 can be realized by the control device 50 executing software, and specifically, the control device 50 is realized by executing each processing procedure of the allowable charge / discharge power change program. Some of the above functions may be realized by hardware.

The operation of the above configuration, particularly each function of the control device 50, will be described in more detail with reference to FIGS. 3 to 5.

FIG. 3 is a flowchart showing a procedure for changing the allowable charge / discharge power according to the deterioration of the cooling performance of the cooling device 30. Each procedure corresponds to each processing procedure of the permissible charge / discharge power change program executed in the control device 50. When the vehicle control system is started by the ignition switch or the like in the vehicle, the allowable charge / discharge power change program is started after the system initialization process. After that, the following processing procedure is executed at a predetermined control cycle.

First, the cooling performance of the cooling device 30 is calculated (S10). This processing procedure is executed by the function of the cooling performance calculation unit 52 of the control device 50. The cooling performance of the cooling device 30 is calculated by using a predetermined calculation method based on the battery temperature θ _B , the battery current I, the intake air temperature θ _A , and the fan speed N. FIG. 4 is a block diagram showing a procedure of a calculation method for calculating the cooling performance of the cooling device 30.

The control device 50 acquires the battery temperature θ _B and the battery current I for the secondary battery 20 (S30, S32), and acquires the intake air temperature θ _A and the fan rotation speed N for the cooling device 30 (S34, S36). ).

If there is no clogging of the filter 36 or the like, the cooling performance of the cooling device 30 depends on the intake air temperature θ _A and the fan speed N. If the intake air temperature θ _A is low, the cooling performance is improved, and if the intake air temperature θ _A is high, the cooling performance is lowered. If the fan speed N is low, the cooling performance is lowered, and if the fan speed N is high, the cooling performance is improved.

The amount of heat generated by the secondary battery 20 depends on the square of the battery current I and the internal resistance of the secondary battery 20. From this calorific value and the cooling performance, the temperature of the secondary battery 20 is estimated on the premise that the cooling is normal (S38). The estimated battery temperature (S40) when cooling is normal and the actual battery temperature (S42), which is the battery temperature θ _B detected by the battery temperature detecting unit 24, are compared. If the cooling is normal, (estimated battery temperature = actual battery temperature). When the cooling performance deteriorates, (estimated battery temperature> actual battery temperature). The larger the amount of decrease in cooling performance, the larger (estimated battery temperature-actual battery temperature = deviation amount). Therefore, the amount of decrease in cooling performance is calculated from the amount of deviation between the actual battery temperature and the estimated battery temperature (S44). In this way, the cooling performance under the battery temperature θ _B , the battery current I, the intake air temperature θ _A , and the fan speed N is calculated.

Returning to FIG. 3, when the cooling performance is calculated, it is then determined whether or not the calculated cooling performance is equal to or less than the predetermined performance (S12). This processing procedure is executed by the function of the cooling performance determination unit 54 of the control device 50. As for the predetermined performance, the cooling performance when the "cooling is normal premise" described in S38 of FIG. 4 is defined as "100% cooling performance" and is shown as a ratio to 100%. Assuming that the predetermined performance is C ₀ %, in S12, it is determined whether or not the calculated cooling performance is C ₀ % or less of the cooling performance when "the premise that the cooling is normal". At C ₀ % of the predetermined performance, if the filter 36 is clogged and no special measures are taken as it is, the battery temperature θ _B frequently exceeds the target upper limit temperature θ _{B 0,} and the secondary battery 20 is hot. It is a cooling performance that may deteriorate if it is continued as it is.

When the determination in S12 is affirmed, a notification of filter clogging is displayed on a display or the like in the vehicle interior (S14), and maintenance is urged to the user. After this display or in parallel with this display, it is determined whether or not the battery temperature θ _B is equal to or higher than a predetermined temperature (S16). This processing procedure is executed by the function of the battery temperature determination unit 56 of the control device 50. The predetermined temperature is set to a temperature lower than the target upper limit temperature θ _B0 by a predetermined margin temperature. The predetermined margin temperature is set to a temperature at which the battery temperature θ _B does not exceed the target upper limit temperature θ _{B 0} by performing the subsequent processes S18 and S20. Such a predetermined margin temperature can be obtained in advance by simulation or the like. As an example, the predetermined margin temperature is in the range of 1 ° C. to 10 ° C., for example, several ° C.

When the determination of S16 is affirmed, it is when the two conditions of the cooling performance of the predetermined performance C ₀ % or less and the battery temperature of the predetermined temperature or more are satisfied. At this time, the amount of reduction with respect to the allowable discharge power and the allowable charge power of + W ₀ and −W _{0 at} the target upper limit temperature θ _{B 0} is calculated (S18). The amount of reduction is calculated according to the cooling performance calculated in S10, and the larger the amount of decrease in cooling performance from C ₀ % of the predetermined performance, the larger the amount of reduction. The maximum value of the amount of reduction is W ₀ , and when the maximum amount of reduction is used, both the allowable discharge power and the allowable charge power at the target upper limit temperature θ _{B 0} become zero. Using the calculated reduction amount, the content of the allowable charge / discharge power described in FIG. 3 is changed according to the reduction amount (S20). The processing procedures of S18 and S20 are executed by the function of the allowable charge / discharge power changing unit 58 of the control device 50.

When the determination of S12 is denied and when the determination of S16 is denied, at least one of the two conditions that the cooling performance is ₀ % or less of the predetermined performance C and the battery temperature is equal to or higher than the predetermined temperature is satisfied. It's time to be unfulfilled. In these cases, since there is no risk of deterioration due to the secondary battery 20 being continued at a high temperature, the allowable charge / discharge power described in S20 is not changed, and the allowable charge / discharge power described in FIG. 3 remains unchanged. (S22). When the processing procedures of S20 and S22 are completed, the process returns to S10 and the above processing procedure is repeated at the next control cycle.

FIG. 5 is a diagram showing an example of changing the allowable charge / discharge power according to the cooling performance described in S18 and S20. FIG. 5A is a diagram showing an example of the allowable power change-related file 64 stored in the memory 60 of FIG. 1, and FIGS. 5B, 5C, and 5D are allowable when the cooling performance is different. It is a figure which shows the example of the change of charge / discharge power.

The vertical axis of FIG. 5A is the constant values W _OUT and W _IN in the allowable discharge power characteristic 72 and the allowable charge power characteristic 82 described in FIG. The horizontal axis is the cooling performance, and the cooling performance when "cooling is normal" is set to 100%, and the ratio to this is shown as a percentage. Since the rate of decrease in cooling performance is indicated by (100-cooling performance)%, the rate of decrease in cooling performance is taken on the lower horizontal axis in the figure of FIG. 5 (a) and the rate of decrease in cooling performance is taken on the upper horizontal axis. It was. C ₀ % of the predetermined performance in the cooling performance is (100-C ₀ )% in the reduction rate of the cooling performance.

As shown in FIG. 5A, when C ₀ % is exceeded even if the cooling performance is lowered, the permissible discharge power characteristic 72 remains + W ₀ , and the permissible charge power characteristic 82 is −W ₀ . Up to this point, the allowable charge / discharge power described in FIG. 2 remains unchanged and is not changed. When the cooling performance is lowered to C ₀ % or less, the permissible discharge power characteristic 72 is reduced from + W ₀ and the permissible charge power characteristic 82 is reduced from −W ₀ according to the cooling performance. When the cooling performance is lowered to 0%, the permissible discharge power characteristic 72 is set to zero, and the permissible charge power characteristic 82 is set to zero. The amount of reduction at this time is W ₀ . The reduction characteristic is a characteristic that connects W ₀ when the cooling performance is C ₀ % and zero when the cooling performance is 0%, and the amount of reduction increases as the cooling performance decreases. FIG. 5A shows an example in which the permissible discharge power characteristic 72 becomes + W ₁ and the permissible charge power characteristic 82 becomes −W ₁ when the cooling performance is C ₁ %. When the cooling performance is C ₁ %, the reduction rate of the cooling performance is (100-C ₁ )%, and the reduction amount in that state is {W _0- W ₁ }. Since W ₁ is obtained by W ₁ = W ₀ (C ₁ / C ₀ ), the reduction amount is calculated by {W ₀ −W ₁ } = [1- (C ₁ / C ₀ )]. The allowable discharge power and the allowable charge power at the target upper limit temperature θ _B0 are changed by using this reduction amount.

In the above, the amount of reduction is assumed to increase linearly as the cooling performance decreases, but this is for the sake of explanation and may be a curvilinear change other than the linear change. The map as shown in FIG. 5A can be obtained in advance by simulation or experiment for the secondary battery 20. In FIG. 5A, the data related to the reduction amount is shown in the map format as the allowable power change-related file 64, but in addition to this, the reduction amount is output by inputting the lookup table format, the mathematical formula relation, and the cooling performance. The ROM format to be used may be used.

FIG. 5B is a diagram showing the allowable charge / discharge powers W _OUT and W _IN when the cooling performance is lowered but exceeds C ₀ %, and has the same characteristics as those in FIG. The permissible discharge power at the target upper limit temperature θ _{B 0} remains + W ₀ , and the permissible charge power remains −W ₀ . Since this state is when the determination in S12 of FIG. 3 is denied, the notification of filter clogging in S14 is not displayed, the process proceeds to S22, and the allowable charge / discharge power is not changed and is left as it is.

FIG. 5C is a diagram showing the allowable charge / discharge powers W _OUT and W _IN when the cooling performance deteriorates and becomes C ₁ % (<C ₀ %). The amount of reduction calculated using FIG. 5 (a) is {W ₀ −W ₁ } = [1- (C ₁ / C ₀ )]. Using this, the permissible discharge power at the target upper limit temperature θ _{B 0} is + W ₁ , and the permissible charge power is −W ₁ . In FIG. 5C, + W ₀ and −W ₀ before reduction are shown by alternate long and short dash lines so that the amount of reduction can be seen. Since this state is when the determination of S12 in FIG. 3 is affirmed, the filter clogging of S14 is notified, the determination of S16 is also affirmed, the process proceeds to S18 and S22, and the allowable charge / discharge power is changed. To.

FIG. 5D is a diagram showing the allowable charge / discharge powers W _OUT and W _IN when the cooling performance is further lowered to 0% (<< C ₀ %). The reduction amount calculated using FIG. 5A is W ₀ . Using this, at the target upper limit temperature θ _B0 , both the allowable discharge power and the allowable charge power become zero. In FIG. 5C, + W ₀ and −W ₀ before reduction are shown by alternate long and short dash lines so that the amount of reduction can be seen. In this state, the determination of S12 in FIG. 3 is affirmed, the determination of S16 is also affirmed, the process proceeds to S18 and S22, and the allowable charge / discharge power is changed.

By using the charge / discharge control system of the secondary battery having the above configuration, when the cooling performance of the cooling device 30 deteriorates, the allowable charge / discharge power is changed to allow the allowable discharge power and the allowable charge at the target upper limit temperature θ _B0 . Reduce power. As a result, it is possible to prevent the secondary battery 20 from continuing at a high temperature, and it is possible to prevent deterioration of the secondary battery 20.

The charge / discharge control device 50 for the secondary battery in the embodiment acquires the battery temperature θ _B and the battery current I of the secondary battery 20. Further, the intake air temperature θ _A , which is the temperature of the air supplied to the filter 36 provided in the cooling device 30 for cooling the secondary battery 20, and the fan rotation speed N of the cooling fan 38 provided in the cooling device 30 are acquired. To do. Then, based on the acquired data, the cooling performance of the cooling device 30 is calculated according to a predetermined calculation method, and the calculated cooling performance is 100% or less when the cooling is normal, and the calculated cooling performance is C ₀ % or less. Judge whether or not. When the cooling performance is ₀ % or less of the predetermined performance C, a notification of filter clogging is displayed, and it is further determined whether or not the acquired battery temperature θ _B is equal to or higher than the predetermined temperature. When the two conditions of the cooling performance of the specified performance C ₀ % or less and the battery temperature of the specified temperature or more are satisfied, the allowable charge / discharge power at the target upper limit temperature θ _{B 0 with} respect to the battery temperature θ _B is _adjusted according to the cooling performance. Change the allowable charge / discharge power to be reduced. The permissible charge / discharge power is changed according to a predetermined change method. When at least one of the two conditions is not satisfied, the allowable charge / discharge power is not changed. As a result, it is possible to prevent the secondary battery 20 from continuing at a high temperature, and it is possible to prevent deterioration of the secondary battery 20.

10 Vehicle system, 11 Main unit, 12, 13 Rotating electric machine, 14 Power control unit (PCU), 20 Secondary battery, 22 Battery pack case, 24 Battery temperature detector, 26 Battery current detector, 30 Cooling device (cooling means) ), 32 Intake port, 33 Cooling air intake, 34 Intake duct, 36 Filter, 38 Cooling fan, 39 Outlet, 40 Intake temperature detector, 42 Fan rotation speed detector, 50 (Secondary battery charge / discharge) control Equipment, 52 Cooling performance calculation unit, 54 Cooling performance determination unit, 56 Battery temperature determination unit, 58 Allowable charge / discharge power change unit, 60 memory, 62 Allowable charge / discharge power related file, 64 Allowable power change related file, 70, 71, 72 Allowable discharge power characteristics, 80, 81, 82 Allowable charge power characteristics.

Claims (1)

With a secondary battery
A battery temperature detecting means for detecting the battery temperature of the secondary battery and
A current detecting means for detecting the battery current flowing through the secondary battery, and
A cooling means for cooling the secondary battery and
An intake air temperature detecting means for detecting an intake air temperature which is a temperature of air supplied to the secondary battery by a cooling fan provided in the cooling means, and an intake air temperature detecting means.
A rotation speed detecting means for detecting the rotation speed of the cooling fan,
A charge / discharge control device that controls charging and discharging of the secondary battery,
The cooling means stores the allowable charge / discharge power related file that associates the allowable charge / discharge power with the battery temperature in the normal operating state, and the memory connected to the charge / discharge control device and the battery.
It is a secondary battery charge / discharge control system equipped with
The allowable charge / discharge power related file is
With respect to the battery temperature in which the first threshold temperature, the second threshold temperature, and the target upper limit temperature at which the secondary battery is desired to be protected from overheating are set in order from the low temperature side to the high temperature side.
When the battery temperature is equal to or lower than the first threshold temperature, the absolute value is set to a constant value, and when the battery temperature is in the range from the first threshold temperature to the second threshold temperature, the temperature becomes higher as the battery temperature becomes higher. It is a file associated with the permissible charge / discharge power that gradually reduces the absolute value from the constant value and sets the absolute value to a constant value of + W ₀ or −W _{0 when} the temperature is equal to or higher than the second threshold temperature and includes the target upper limit temperature . ,
The charge / discharge control device is
A cooling performance calculation unit that calculates the cooling performance of the cooling means based on the battery temperature, the battery current, the intake air temperature, and the rotation speed.
A cooling performance determination unit that determines whether or not the cooling performance calculated by the cooling performance calculation unit is equal to or less than a predetermined performance,
When the cooling performance is equal to or lower than the predetermined performance, a battery temperature determination unit for determining whether or not the battery temperature is equal to or higher than the predetermined temperature,
The cooling performance is not more than the predetermined performance, and, when said battery temperature is the predetermined temperature or higher, the allowable discharge electric power in the relation file the target upper limit temperature to about it have been set the allowable discharge electric power of + W to a constant value of ₀ or -W _0, the allowable wherein with a decrease in the cooling performance is reduced from + W ₀ or -W _0, wherein when the cooling performance is zero for setting the allowable discharge electric power to zero Allowable charge / discharge power change unit that changes charge / discharge power,
Secondary battery charge / discharge control system, including.

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