JP2008282699A - Cooling device of battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prolong the lifetime of a battery having a fast deterioration speed (rate of change (k) of an internal resistance is large), by improving a battery cooling device equipped with a cooling fan to cool the chargeable and dischargeable battery by supplying cooling air to it. <P>SOLUTION: In a battery controller, a rate of change (k) of the internal resistance of a battery is computed based on an output signal from a battery voltage sensor and a battery current sensor, and either one of prescribed temperature lowering control to lower an operation starting temperature Ts forming a threshold temperature at which a cooling fan starts its operation when the computed rate of change (k) of the internal resistance is larger than a prescribed rate of change (a), and air quantity increasing control to increase the air quantity of the cooling fan when the rate of change (k) of the internal resistance is larger than the prescribed rate of change (a) is performed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention belongs to a technical field related to a battery cooling apparatus including a cooling unit that cools a battery by supplying cooling air to a chargeable / dischargeable battery.

In this type of battery cooling device, a cooling fan is usually used as a cooling means. For example, in the device disclosed in Patent Document 1, a cooling fan as the cooling means, a temperature sensor for detecting the temperature of the battery, When the battery temperature detected by the temperature sensor is equal to or higher than a preset temperature (predetermined temperature), the cooling fan is driven to cool the battery. Yes. Thereby, the temperature rise due to the heat generation of the battery is suppressed, the charge / discharge efficiency is improved, and the life is extended.
JP 2005-63689 A

  By the way, even if the elapsed time from the start of use of the normal battery is the same, the performance deterioration rate (internal resistance) due to the use state (charge / discharge frequency, etc.), the quality variation at the time of manufacture, etc. A difference occurs in the degree of increase).

  For this reason, a battery having a high performance deterioration rate cannot exhibit a predetermined performance before a preset quality assurance period elapses, and requires early replacement. As a result, there is a problem that the cost burden on the user accompanying battery replacement increases.

  Therefore, for a battery with a high performance deterioration rate, for example, as shown in Patent Document 1 described above, when the battery temperature reaches a predetermined temperature or higher, cooling is performed by operating a cooling fan to increase the temperature due to the heat generation. It is conceivable to extend the life by suppressing it.

  However, in the battery cooling device shown in Patent Document 1 described above, the battery is cooled under the same cooling condition regardless of the battery performance deterioration rate. For this reason, a battery having a fast performance deterioration rate is used as a reference. When cooling is performed, a battery with a slow deterioration rate is cooled more than necessary. When cooling is performed based on a battery with a slow deterioration rate, the battery with a fast deterioration rate is sufficiently cooled. There is a problem that can not be.

  The present invention has been made in view of such a point, and an object of the present invention is to provide a battery cooling device including a cooling unit that cools a chargeable / dischargeable battery by supplying cooling air. On the other hand, by contriving the configuration and control method, it is intended to achieve the battery cooling with the optimum cooling amount according to the performance deterioration speed while extending the life of the battery having a high performance deterioration speed. .

  In order to achieve the above object, the present invention comprises an internal resistance increase degree detecting means for detecting the internal resistance increase degree of the battery, and the internal resistance increase degree detected by the internal resistance increase degree detecting means is When the temperature is higher than the predetermined degree, the control for lowering the threshold temperature (predetermined temperature) of the battery that starts the operation of the cooling fan is reduced. When the internal resistance increase degree is higher than the predetermined degree, At least one of the air volume increase control to be increased is executed.

  Specifically, the invention of claim 1 is directed to a battery cooling device including a cooling unit that cools the battery by supplying cooling air to the chargeable / dischargeable battery.

  Battery temperature detection means for detecting the temperature of the battery; internal resistance increase degree detection means for detecting the internal resistance increase degree of the battery; temperature information from the battery temperature detection means and the internal resistance Battery cooling control means for supplying cooling air to the battery by the cooling means based on the internal resistance information from the degree-of-rise detection means, and the battery cooling control means is controlled by the battery temperature detection means. When the detected battery temperature rises above a predetermined temperature, the cooling means supplies cooling air to the battery, and the internal resistance detected by the internal resistance rise degree detecting means is executed. When the degree of increase in resistance is greater than the predetermined degree, it is higher than when the degree of increase in internal resistance is less than or equal to the predetermined degree. Compared to the predetermined temperature decrease control for decreasing the predetermined temperature and the internal resistance increase degree detected by the internal resistance increase degree detecting means when the internal resistance increase degree is larger than the predetermined degree, the internal resistance increase degree is less than or equal to the predetermined degree. Then, at least one of the air volume increase control for increasing the air volume of the cooling air supplied to the battery by the cooling means when the battery temperature rises is assumed to be executed.

  With the above configuration, when the temperature of the battery detected by the battery temperature detecting unit is equal to or higher than a predetermined temperature, the battery cooling control unit supplies cooling air from the cooling unit to the battery. .

  Further, when the internal resistance increase degree detected by the internal resistance increase degree detection means is equal to or greater than a predetermined degree, the battery cooling control means executes at least one of the predetermined temperature decrease control and the air volume increase control. As a result, it becomes possible to further enhance the cooling of the battery as compared with the case where the degree of increase in the internal resistance is not more than a predetermined degree.

  That is, when the internal resistance increase degree detected by the internal resistance increase degree detection means is larger than the predetermined degree, when the predetermined temperature decrease control is executed by the battery cooling control means, the internal resistance increase degree is the predetermined degree. The predetermined temperature is set lower than the following time, and as a result, the supply start timing of the cooling air to the battery by the cooling means is advanced. That is, battery cooling by the cooling means is started in a state where the battery temperature is lower than when the degree of increase in internal resistance is equal to or less than a predetermined degree. It is possible to suppress an increase in the degree of resistance increase, that is, an increase in performance degradation rate (hereinafter referred to as degradation rate).

  Further, in the case where the internal resistance increase degree detected by the internal resistance increase degree detection means is larger than a predetermined degree, when the air volume increase control is executed by the battery cooling control means, the internal resistance increase degree is less than the predetermined degree. The amount of cooling air supplied to the battery by the cooling means when the battery temperature rises is set to be larger than that at the time of the battery temperature, thereby maintaining the temperature of the battery at a lower temperature and increasing the degree of internal resistance due to heat generation. The increase can be suppressed.

  Therefore, when the internal resistance increase degree detected by the internal resistance increase degree detecting means is larger than the predetermined degree, that is, when the deterioration rate of the battery is faster than the predetermined speed, at least one of the predetermined temperature decrease control and the air volume increase control. By suppressing the increase in the internal resistance of the battery, the increase in the deterioration rate can be suppressed. In this way, it is possible to extend the life of a battery having a high deterioration rate.

  Further, when the internal resistance increase degree detected by the internal resistance increase degree detecting means is not more than a predetermined degree, that is, when the deterioration speed is not more than a predetermined speed, the predetermined temperature decrease control and the air volume increase control are not executed. It is possible to prevent the battery performance from deteriorating by cooling the battery having a relatively slow speed more than necessary. That is, it is possible to cool the battery with an optimal cooling amount according to the deterioration rate of the battery.

  According to a second aspect of the present invention, in the first aspect of the invention, when the battery cooling control means executes the predetermined temperature decrease control, the internal resistance increase degree detected by the internal resistance increase degree detection means is large. It is assumed that the predetermined temperature is lowered as much as possible.

  Thus, when the predetermined temperature decrease control is performed by the battery cooling means, the predetermined temperature is set lower as the internal resistance increase degree detected by the internal resistance increase degree detecting means is larger. Accordingly, as the degree of increase in the internal resistance of the battery increases, that is, as the deterioration rate increases, battery cooling by the cooling means is started in a state where the battery temperature is lower. As a result, it is possible to prevent the temperature rise of the battery having a high deterioration rate more reliably and to extend its life. Therefore, it is possible to obtain the same effect as in claim 1 more effectively.

  In addition, the cooling start temperature (predetermined temperature) of the battery having a slow deterioration rate does not decrease more than necessary, and therefore, it is possible to prevent the performance of the battery from being deteriorated due to the overcooling state. .

  According to a third aspect of the invention, in the first or second aspect of the invention, when the battery cooling control means executes the air volume increase control, the internal resistance increase degree detected by the internal resistance increase degree detection means is The larger the battery temperature, the greater the amount of cooling air supplied to the battery by the cooling means when the battery temperature rises.

  Accordingly, when the air volume increase control by the battery cooling means is executed, the larger the internal resistance increase degree detected by the internal resistance increase degree detecting means, the more the cooling air supplied to the battery by the cooling means when the battery temperature rises. A large air volume is set, which makes it possible to more reliably prevent the temperature of a battery having a fast deterioration rate from being increased and to extend its life. Therefore, it is possible to obtain the same effect as in claim 1 more effectively.

  Moreover, it is possible to prevent the battery from being overcooled and reducing its performance without supplying cooling air with an unnecessarily large amount of airflow to a battery with a slow deterioration rate. Become.

  According to a fourth aspect of the invention, in the invention according to any one of the first to third aspects, the battery cooling control means increases the battery temperature detected by the battery temperature detecting means when the battery temperature rises. The cooling means is configured to increase the amount of cooling air supplied to the battery.

  As a result, the higher the battery temperature detected by the battery temperature detecting means, the greater the amount of cooling air supplied to the battery by the cooling means when the battery temperature rises. Therefore, as the temperature of the battery is higher, the cooling is strengthened, and the increase in the degree of increase in internal resistance can be reliably suppressed. Therefore, the same effect as that of the first to third aspects of the invention can be obtained more reliably.

  According to a fifth aspect of the invention, in the invention according to any one of the first to fourth aspects, when the battery is used while maintaining the degree of increase in internal resistance at the predetermined degree, the battery is preset after the start of use. When the internal resistance value reaches a predetermined resistance value when the set time elapses, and the battery cooling control means detects that the internal resistance increase degree detected by the internal resistance increase degree detection means is larger than the predetermined degree, Execute the predetermined temperature and the air volume increase control at the time of the predetermined temperature decrease control so that the internal resistance increase degree of the battery is decreased and the internal resistance value becomes the predetermined resistance value when the set time elapses. It is assumed that the air volume of the cooling air at the time is set.

  By doing so, it is possible to prevent a decrease in battery performance caused by cooling the battery more than necessary by the cooling means.

  That is, as described above, the threshold temperature (predetermined temperature) of the battery at which the cooling of the battery is started by the cooling unit is reduced by the execution of the predetermined temperature decrease control by the battery cooling control unit. If the temperature is set too low, the time until the battery reaches the predetermined resistance value (battery life time) can be made sufficiently longer than the set time (quality assurance period). There is a problem that the temperature is lowered too much (becomes a supercooled state) and the performance is lowered.

  Similarly, the amount of cooling air supplied from the cooling means to the battery increases when the battery temperature rises due to the execution of the air volume increase control by the battery cooling control means, but this air volume is set too much. In such a case, the battery life time can be sufficiently secured, but the battery temperature rise suppression action by the cooling air acts excessively, so that the battery becomes in an overcooled state and its performance is deteriorated. There is.

  However, according to the present invention, the battery cooling control means performs the predetermined temperature during the predetermined temperature decrease control and the air volume increase control so that the internal resistance value reaches the predetermined resistance just when the set time elapses. Thus, it is possible to reliably prevent a decrease in battery performance caused by cooling the battery more than necessary.

  As described above, according to the battery cooling device of the present invention, the internal resistance detected by the internal resistance increase degree detecting means is provided with the internal resistance increase degree detecting means for detecting the internal resistance increase degree of the battery. When the degree of increase is greater than the predetermined degree, the cooling fan starts the operation of the cooling fan, and when the internal temperature increase degree is greater than the predetermined degree, the cooling fan lowers the threshold temperature (predetermined temperature) of the battery. By performing at least one of the air volume increase control for increasing the air volume of the battery, it is possible to extend the life of the battery having a fast deterioration speed and to cool the battery with an optimal cooling amount corresponding to the deterioration speed. Is possible.

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

(Embodiment 1)
FIG. 1 shows a configuration of a drive system of an automobile A on which a battery cooling device according to Embodiment 1 of the present invention is mounted. The vehicle A is a hybrid vehicle A that includes the engine 1 and the motor 21 as drive sources and travels by combining the engine 1 and the motor 21. The hybrid vehicle A employs a so-called series / parallel system, and a crankshaft, which is an output shaft of the engine 1, is connected to a motor 21 and a generator 22 through a power split mechanism 4, and the motor 21 further includes a differential mechanism ( A differential gear 61 is connected to the drive wheel 6. Thus, in the automobile A, the power generated by the engine 1 is appropriately divided and transmitted to the generator 22 and the drive wheel 6 (motor 21) by the power split mechanism 4.

  The automobile A is equipped with an engine control computer (ECU) 5, and the engine 1, the motor 21 and the generator 22 are controlled by the ECU 5.

  The engine 1 (hereinafter referred to as the engine 1) is a gasoline engine that uses gasoline as fuel to generate the driving force of the automobile A. In the present embodiment, although not shown in the drawings, the engine 1 has a trochoid inner peripheral surface. A rotary engine including a substantially triangular rotor that is housed in a rotor housing chamber (cylinder) surrounded by a cylindrical rotor housing and a side housing and supported so as to perform planetary rotational movement with respect to a crankshaft. Has been. In other words, the rotor rotates around the eccentric wheel of the crankshaft while the seal portions respectively disposed on the three tops of the outer periphery thereof are in contact with the trochoid inner peripheral surface of the rotor housing. It revolves around the shaft center, and while the rotor makes one rotation, the working chamber formed between the tops of the rotor moves in the circumferential direction, and intake, compression, expansion (combustion) And each process of exhaust is performed, and the rotational force generated by this is output from the crankshaft via the rotor.

  Further, the engine 1 is of a two-rotor type in which two rotor housings are integrated so as to be sandwiched between three side housings, and the rotors are accommodated in two cylinders formed therebetween, respectively. Two spark plugs are provided for each cylinder.

  The engine 1 is not limited to a rotary engine but may be a reciprocating engine.

  The crankshaft of the engine 1 is connected to two motor generators 21 and 22 via a power split mechanism 4. Both of these motor generators 21 and 22 are designed so that their functions are switched between the electric motor and the generator depending on the situation. In a normal driving situation, the motor / generator 21 is an auxiliary engine. The motor / generator 22 is mainly responsible for a function as an electric motor that generates power, and serves mainly as a generator that generates power using the power of the engine 1. Therefore, in the following description, the motor / generator 21 is referred to as a motor (drive motor), and the motor / generator 22 is referred to as a generator.

  The power split mechanism 4 is a planetary gear having a sun gear, a ring gear, and a planetary carrier. The sun gear is connected to the generator 22, the ring gear is connected to the motor 21, and the planetary carrier is connected to the engine 1.

  The motor 21 and the generator 22 are connected to the battery 71 via the inverter 25.

  As shown in FIG. 2, the battery 71 is a part of the battery module 7, and the battery module 7 is disposed on the downstream side of the outside air intake duct 72 for taking in outside air and the duct 72. A cooling fan 73, a case 74 in which the battery 71 is accommodated, a discharge duct 75 that is provided in the case 74 and discharges outside air supplied into the case 74, and a plurality of (see FIG. In the example, there are three battery temperature sensors 76, a battery voltage sensor 31 for detecting battery voltage, a battery current sensor 32 for detecting battery current, and a battery controller 77 for controlling the operation of the battery 71. In addition.

  The outside air intake duct 72, the cooling fan 73, the case 74, and the discharge duct 75 constitute a cooling path that supplies and discharges the outside air around the battery 71 as the cooling fan 73 is driven (see FIG. (See the white arrow).

  The battery controller 77 calculates an SOC (state of charge) based on the temperature information from the battery temperature sensor 76 and the battery current / voltage information from the battery voltage sensor 31 and the battery current sensor 32 and transmits the information to the ECU 5. At the same time, the charging / discharging operation of the battery 71 is controlled in response to a command from the ECU 5. The battery controller 77 controls the cooling of the battery 71 by controlling the rotational drive of the cooling fan 73 as will be described later. Details of cooling control of the battery 71 by the battery controller 77 will be described later.

  As shown in FIG. 1, output signals from the battery controller 77 and various sensors 24 are input to the ECU 5. The ECU 5 determines the traveling state of the automobile A based on these output signals. Then, the engine 1, the motor 21, and the generator 22 are controlled according to the traveling state, and the battery 71 is charged and discharged by outputting a necessary control signal to the battery controller 77. That is, the control of the engine 1 is performed by controlling the fuel injection amount and ignition timing of each cylinder according to the traveling state, and the inverter 25 is controlled by outputting a control signal to the battery controller 77. Thus, the current flowing between the motor 21 and the battery 71 and the current flowing between the generator 22 and the battery 71 are adjusted to control the output and rotation speed of the motor 21 and the power generation amount and rotation speed of the generator 22. To do.

  Specifically, in a region where the rotation of the drive wheel 6 is low speed and high load and the operation efficiency of the engine 1 is reduced, such as when starting or running at a low speed, the operation of the engine 1 is stopped and the power of the motor 21 is reduced. Only the driving wheel 6 is driven. On the other hand, during normal travel, the engine 1 is operated and its power is transmitted to the drive wheels 6 via the power split mechanism 4, and the power is also transmitted to the generator 22 via the power split mechanism 4 to generate power. Is called. The electric power generated by the generator 22 is supplied to the motor 21 and the motor 21 is used as auxiliary power for the engine 1. Depending on the running state during the normal running, the power generation amount of the generator 22 is decreased to reduce or stop the power assist by the motor 21, or the power generation amount of the generator 22 is increased to improve the power assist by the motor 21. To do.

  Next, the cooling control processing of the battery 71 in the battery controller 77 will be described with reference to the flowchart shown in FIG.

  First, in the first step S1, detection signals output from the battery voltage sensor 31, the battery current sensor 32, and the battery temperature sensor 76 are read.

  In step S2, the SOC of the battery 71 is calculated based on the detection signals from the battery voltage sensor 31 and the battery current sensor 32 read in step S1.

  Specifically, the storage amount (remaining capacity of the battery 71) is calculated by time integration of the current value of the battery 71 calculated based on the detection signal from the battery current sensor 32. Then, the SOC (%) is calculated from the remaining capacity of the battery 71. It is calculated as SOC (%) = (remaining battery capacity) / (full charge amount) × 100. In addition, the calculated SOC is timely corrected based on the voltage value (open circuit voltage value) of the battery 71 calculated based on the detection signal from the battery voltage sensor 32 during charge / discharge suspension.

  In step S3, it is determined whether or not the battery 71 is in a state after the start of discharge and a predetermined time has elapsed since the start of discharge. If this determination is YES, the process proceeds to step S4. If NO, the process returns. To do.

  Specifically, when the SOC tends to decrease and a predetermined time has elapsed since the current began to flow in the discharge direction, a determination of YES is made assuming that the predetermined time has elapsed since the battery 71 started discharging, Otherwise, NO is determined.

  In step S4, the internal resistance value of the battery 71 is calculated. Specifically, a voltage drop amount (IR drop) ΔV from when the battery 71 starts to discharge until the predetermined time elapses is calculated, and this voltage drop amount ΔV is calculated when the battery 71 is discharged. The internal resistance value is calculated by dividing by the current value.

  In step S5, the internal resistance value calculated in step S4 is converted into a standard value. The conversion to the standard value is performed based on a conversion map (see FIG. 4) stored in the memory of the battery controller 77. This conversion map is stored in the memory in advance for each parameter set including three parameters of battery temperature, SOC, and internal resistance value.

  Here, the standard value is a value obtained by converting an internal resistance value calculated under different conditions of SOC, battery temperature, etc. into an internal resistance value under a predetermined condition. In this embodiment, the battery temperature is The internal resistance value (standard value) when SOC is 50% at 25 ° C.

  FIG. 4 is a conversion map corresponding to, for example, a battery temperature of 40 ° C., an SOC of 90%, and an internal resistance value of 330 mΩ (a value corresponding to point A). According to this conversion map, the battery temperature is 25 ° C. When the SOC is 50%, the internal resistance value, that is, the standard value is 550 mΩ (value corresponding to point B in the figure).

  In step S6, as shown in FIG. 5, the standard value converted in step S5 is tabulated together with the calculation date and time of the internal resistance value that is the basis thereof and stored in the memory. In the following description, this standard value is referred to as a standardized internal resistance value.

  In step S7, the average value of the standardized internal resistance value for each day is calculated, and based on this average value, the rate of change of the standardized internal resistance value from the start of use (at the time of the first discharge) to the present time ( This corresponds to the degree of increase in internal resistance and is hereinafter referred to as internal resistance change rate k).

  Here, at the stage where the standardized internal resistance value is calculated, the standardized internal resistance average value on the calculated date cannot be calculated. If is not operating, the average value of the standardized internal resistance values calculated on the day closest to that day is set as the standardized internal resistance value at the present time.

  Specifically, a calculation method of the standardized internal resistance value at the present time will be described based on FIG. That is, for example, when the standardized internal resistance value R4 is calculated at 10:00 on March 2, the average value of all the standardized internal resistance values calculated on March 2 at this time is calculated. Therefore, the average value (= (R1 + R2 + R3) / 3) of all the standardized internal resistance values calculated on March 1, which is the closest day to March 2, is the current standard. Internal resistance value. In the following description, the averaged normalized internal resistance value is simply referred to as an internal resistance value.

  Further, as shown in FIG. 6, by dividing the difference between the current internal resistance value Rn of the battery 71 and the internal resistance value Ro at the start of use by the use time S1 from the start of use to the present time. The internal resistance change rate k is calculated. The internal resistance change rate k corresponds to the slope of a graph drawn with the horizontal axis as the time axis and the vertical axis as the internal resistance value. Here, the time axis on the horizontal axis is set to the time itself, the square root of the time, or the logarithm so that the change in the internal resistance value is linear.

  In the present embodiment, the internal resistance value is calculated only when the battery 71 is discharged, and the internal resistance change rate k is calculated based on the average value of the calculated value for one day. For example, the internal resistance value is calculated from the battery current and the battery voltage, and the internal resistance value is calculated by creating a graph with the internal resistance value as the vertical axis and the horizontal axis as the time axis. , And the slope of the point plotted by the method of least squares may be calculated, and the internal resistance change rate k may be calculated from this slope.

  In step S8, it is determined whether or not the internal resistance change rate k calculated in step S7 is larger than a predetermined change rate a. If this determination is YES, the process proceeds to step S9. If NO, step S12 is performed. Proceed to Here, the predetermined change rate a is just the life time of the battery 71 when the battery 71 is continuously used with its internal resistance change rate k kept at the predetermined change rate a after the start of use. The rate of change is such that a predetermined set time Sd (see FIG. 14) is reached.

  In step S9, a cooling condition is set according to the magnitude of the internal resistance change rate k calculated in step S8. Here, the cooling condition is a condition including an operation start temperature Ts that is a threshold temperature of the battery 71 at which the operation of the cooling fan 73 is started, and a fan airflow q when the cooling fan is operated. In step S9, the fan air volume q is set to a constant amount q1 (l / s) regardless of the magnitude of the internal resistance change rate k, and the operation start temperature Ts decreases as the internal resistance change rate k increases. (See FIGS. 7 and 8). Specifically, when the internal resistivity k = a, the operation start temperature Ts = 40 ° C., and when the internal resistance change rate k = 1.5a, the operation start temperature Ts = 32.5 ° C. When the rate k = 2.0a, the operation start temperature Ts = 25 ° C. Since the ambient temperature around the battery 71 is usually about 25 ° C., the lower limit value of the operation start temperature Ts of the cooling fan 73 is also set to 25 ° C. as shown in FIG. Instead, it may be set lower.

  In step S10, the battery temperature is calculated based on the detection signal from the battery temperature sensor 76 read in step S1, and it is determined whether or not the calculated battery temperature is equal to or higher than the operation start temperature Ts. If YES, the process proceeds to step S11. If NO, the process returns.

  In step S11, the cooling fan 73 is driven with the fan rotational speed set in step S9 or step S12 (described later).

  In step S12 which proceeds when the determination in step S8 is NO, the cooling condition is fixed to a constant condition regardless of the magnitude of the internal resistance change rate k.

  Specifically, in step S12 of the present embodiment, as shown in FIG. 8, the fan air volume q of the cooling fan 73 is set to a constant amount q1 (l / s), and the operation start temperature Ts of the cooling fan 73 is set. Is a constant temperature of 40 ° C.

  As described above, in the first embodiment, the battery controller 77 determines that the temperature of the battery 71 detected by the battery temperature sensor 76 rises to the operation start temperature Ts (predetermined temperature or higher) (YES in step S10). In this case, the cooling fan 73 supplies cooling air to the battery 71 (cooling control of the battery 71), and the calculation is based on the outputs from the battery voltage sensor 31 and the battery current sensor 32. When the internal resistance change rate k is larger than the predetermined change rate a (when the determination at step S8 is YES), when the internal resistance change rate k is equal to or less than the predetermined change rate a (the determination at step S8 is NO). The predetermined temperature lowering control (the control process of step S9) is executed to lower the operation start temperature Ts (predetermined temperature) compared to It is configured.

  Thereby, when the internal resistance change rate k of the battery 71 is larger than the predetermined change rate a, that is, when the deterioration rate of the battery 71 is relatively fast, compared to the case where the internal resistance change rate k is equal to or less than the predetermined change rate a. Thus, cooling of the battery 71 by the cooling fan 73 is started in a state where the battery temperature is lower, thereby keeping the temperature of the battery 71 at a low temperature and increasing the internal resistance change rate k, that is, increasing the deterioration rate. As a result, it is possible to extend the life of the battery 71.

  In the first embodiment, the battery controller 77 is configured to decrease the operation start temperature Ts as the internal resistance change rate k increases when the predetermined temperature decrease control is executed (when the control process of step S9 is executed). Has been. That is, the battery controller 77 linearly decreases the operation start temperature Ts of the cooling fan 73 as the internal resistance change rate k increases when the predetermined temperature decrease control is executed (see FIG. 7).

  As a result, as the internal resistance change rate k of the battery 71 increases, that is, as the deterioration rate increases, battery cooling by the cooling fan 73 is started in a state where the battery temperature is lower. Accordingly, the battery 71 can be cooled in accordance with the deterioration rate. As a result, the battery temperature becomes lower than necessary and the battery performance is deteriorated even though the deterioration rate of the battery 71 is relatively slow. It becomes possible to prevent.

(Embodiment 2)
FIG. 9 shows the second embodiment of the present invention, in which the cooling condition set by the battery controller 77 is different from that of the first embodiment when the internal resistance change rate k is larger than the predetermined change rate a. is there. Note that the cooling control process of the battery 71 by the battery controller 77 in this embodiment is different from the first embodiment only in the cooling condition setting process in step S9 in the flowchart shown in FIG. Is the same as in the first embodiment. In the following embodiments (Embodiments 2 to 5), the hardware configuration such as the battery module 7 and the engine 1 is the same as that of the first embodiment.

  That is, in the present embodiment, the battery controller 77 operates the cooling fan 73 in step S9 that proceeds when the internal resistance change rate k is larger than the predetermined change rate a (when the determination in step S8 in FIG. 3 is YES). The starting temperature Ts is set to a constant temperature of 40 ° C. regardless of the magnitude of the internal resistance change rate k, while the fan air volume q during the operation of the cooling fan increases linearly as the internal resistance change rate k increases. Set (see FIG. 9 and FIG. 10).

  Specifically, in the present embodiment, when the internal resistance change rate k ≦ a, the fan air volume q = q1 (l / s) is set when the cooling fan is operating, and when the internal resistance change rate k = 2.0a. The fan air volume q = q3 (l / s) is set. When k = 1.5a, the fan air volume q = q2 = q1 + (q3-q1) × 0.5 is set by proportional calculation.

  Note that the battery controller 77 sets the operation start temperature Ts of the cooling fan 73 at the above-described time in step S12 that proceeds when the internal resistance change rate k is equal to or less than the predetermined change rate a (when the determination in step S8 is NO). As in the first embodiment, the constant temperature is set to 40 ° C. regardless of the magnitude of the internal resistance change rate k, and the air flow q of the cooling fan 73 is set to a constant q1 (l / s).

  As described above, in the second embodiment, the battery controller 77 performs the cooling fan 73 when the temperature of the battery 71 detected by the battery temperature sensor 76 becomes a predetermined temperature or higher (when YES in step S10). The cooling air is supplied to the battery 71 (cooling control of the battery 71) by the control, and the internal resistance change rate k calculated based on the outputs from the battery voltage sensor 31 and the battery current sensor 32 changes predetermined. When the rate is greater than the rate a (YES in step S8), the cooling fan is increased when the battery temperature rises compared to when the internal resistance change rate k is less than or equal to the predetermined rate of change a (NO in step S8). 73 is configured to execute air volume increase control for increasing the volume of cooling air supplied to the battery 71 by 73.

  Thereby, when the internal resistance change rate k of the battery 71 is larger than the predetermined change rate a, that is, when the deterioration rate of the battery 71 is relatively fast, compared to the case where the internal resistance change rate k is less than the predetermined change rate a. Thus, the amount of cooling air supplied from the cooling fan 73 to the battery 71 when the battery temperature rises increases, and as a result, the temperature of the battery is kept at a lower temperature and the increase in the internal resistance change rate k is suppressed. Is possible. Therefore, as in the first embodiment, it is possible to extend the life of the battery 71 having a high deterioration rate.

  In the second embodiment, the battery controller 77 causes the cooling fan 73 to use the battery 71 when the battery temperature rises as the internal resistance change rate k increases as the air volume increase control is executed (when the control process in step S9 is executed). It is comprised so that the air volume q of the cooling air supplied to may be increased. That is, when the air volume increase control is executed, the battery controller 77 linearly increases the fan flow rate when the cooling fan is operated from q1 (l / s) to q3 (l / s) as the internal resistance change rate k increases (FIG. 10).

  Thus, the larger the internal resistance change rate k of the battery 71, that is, the greater the deterioration rate, the more cooling air is supplied from the cooling fan 73 to the battery 71 when the battery temperature rises. Thereby, the cooling air can be supplied to the battery 71 in accordance with the deterioration speed of the battery 71, and the battery 71 can be effectively cooled. For this reason, although the deterioration rate of the battery 71 is relatively slow, a decrease in battery performance due to an excessive cooling air being supplied from the cooling fan 73 and the battery 71 being in an overcooled state is prevented. It becomes possible.

(Embodiment 3)
FIG. 11 shows a third embodiment of the present invention. When the internal resistance change rate k is larger than the predetermined change rate a, the cooling conditions set by the battery controller 77 are different from those in the first and second embodiments. It is In addition, about the cooling control process of the battery 71 by the battery controller 77 in this embodiment, the setting process of the cooling condition of step S9 in the flowchart shown in FIG. 3 differs from the said Embodiment 1, and about other processes, The same as in the first embodiment.

  In other words, in the present embodiment, the battery controller 77 proceeds to step S9 when the internal resistance change rate k is greater than the predetermined change rate a (when the determination in step S8 in FIG. 3 is YES). As with the second embodiment, the cooling fan air volume q is set so as to increase linearly as the internal resistance change rate k increases (see FIG. 10), and the operation start temperature Ts is set similarly to the first embodiment. The internal resistance change rate k is set so as to decrease linearly (see FIG. 7).

  More specifically, in the present embodiment, as shown in FIG. 11, when the internal resistance change rate k ≦ a, the cooling fan air volume q = q1 (l / s) and the operation start temperature Ts = 40 ° C. are set. When the internal resistance change rate k = 2.0a, the cooling fan airflow q = q3 (l / s) and the operation start temperature Ts = 25 ° C. are set. When k = 1.5a, the cooling fan airflow q = q2 = q1 + (q3-q1) × 0.5 and the operation start temperature Ts = 32.5 ° C.

  Note that the battery controller 77 sets the operation start temperature Ts of the cooling fan 73 at the above-described time in step S12 that proceeds when the internal resistance change rate k is equal to or less than the predetermined change rate a (when the determination in step S8 is NO). As in the first and second embodiments, the constant temperature is set to 40 ° C. regardless of the magnitude of the internal resistance change rate k, and the air volume q of the cooling fan 73 is set to a constant q1 (l / s). .

  As described above, in the third embodiment, the battery controller 77 causes the cooling fan 73 when the temperature of the battery 71 detected by the battery temperature sensor 76 is equal to or higher than the predetermined temperature (when YES in step S10). The cooling air is supplied to the battery 71 (cooling control of the battery 71) by the control, and the internal resistance change rate k calculated based on the outputs from the battery voltage sensor 31 and the battery current sensor 32 changes predetermined. When the internal resistance change rate k is less than or equal to the predetermined change rate a (when the determination at step S8 is NO) when the rate a is greater than the rate a (when the determination at step S8 is YES), Predetermined temperature decrease control for decreasing Ts (predetermined temperature), and when the internal resistance change rate k is larger than the predetermined change rate a (step S8) There when) YES, the is configured to perform both the air volume increasing control for increasing the amount of cooling air supplied to the battery 71 by the battery temperature rise during the cooling fan 73.

  As a result, when the internal resistance change rate k is larger than the predetermined change rate a, the battery controller 77 performs both the predetermined temperature decrease control and the air volume increase control. As a result, the battery temperature of the cooling fan 73 is reduced. In addition to being able to operate early at a relatively low stage, it is possible to further increase cooling of the battery 71 by increasing the amount of fan air supplied to the battery 71 when the battery temperature rises. Therefore, it is possible to obtain the same operational effects as those of the first and second embodiments more reliably.

(Embodiment 4)
FIG. 12 shows a fourth embodiment of the present invention, in which the cooling conditions set by the battery controller 77 are different from those of the first to third embodiments. Note that the cooling control processing of the battery 71 by the battery controller 77 in this embodiment differs from the first to third embodiments only in the setting of the cooling conditions in steps S9 and S12 in the flowchart shown in FIG. Other processes are the same as those in the first to third embodiments.

  That is, in the present embodiment, the battery controller 77 starts the cooling fan operation in step S9 that proceeds when the internal resistance change rate k is greater than the predetermined change rate a (when the determination in step S8 in FIG. 3 is YES). As in the second embodiment, the fan air volume q at the time is set so as to increase linearly as the internal resistance change rate k increases (see FIG. 10). The operation start temperature Ts is set to increase linearly as the temperature increases (see FIG. 12), and the operation start temperature Ts is set to decrease linearly as the internal resistance change rate k increases as in the first embodiment (see FIG. 12). (See FIG. 7).

  Further, in step S12 that proceeds when the internal resistance change rate k is equal to or less than the predetermined change rate a (when the determination in step S8 of FIG. 3 is NO), the battery controller 77 determines the fan airflow q at the start of the cooling fan operation. Is set to q1 (l / s), and the fan flow rate q after starting the cooling fan operation is set so as to increase linearly as the battery temperature increases (see FIG. 11). Ts is set to a constant temperature of 40 ° C., regardless of the magnitude of the internal resistance change rate k, as in the first to third embodiments.

  As described above, in the fourth embodiment, the battery controller 77 is configured to execute both the predetermined temperature decrease control and the air volume increase control, as in the third embodiment. Thereby, the same effect as the said Embodiment 1 thru | or Embodiment 3 can be acquired.

  In the fourth embodiment, when the battery temperature rises, the battery controller 77 increases the amount of cooling air supplied to the battery 71 by the cooling fan 73 as the temperature of the battery 71 detected by the battery temperature sensor 76 increases. It is configured to increase.

  As a result, when the battery temperature rises, the higher the battery temperature, the stronger the cooling by the cooling fan 73. Therefore, it is possible to reliably suppress the increase in the internal resistance change rate k due to the rise in the battery temperature. It becomes. Therefore, it is possible to obtain the same operational effects as those of the first to third embodiments more reliably.

(Embodiment 5)
FIG. 13 shows a fifth embodiment of the present invention, in which the cooling condition set by the battery controller 77 is different from that of the fourth embodiment when the internal resistance change rate k is larger than the predetermined change rate a. is there. Note that the cooling control processing of the battery 71 by the battery controller 77 in this embodiment is different from the fourth embodiment only in the cooling condition setting processing in step S9 in the flowchart shown in FIG. Is the same as in the fourth embodiment.

  That is, in the present embodiment, the battery controller 77 first sets the target internal resistance in step S9 that proceeds when the internal resistance change rate k is greater than the predetermined change rate a (when the determination in step S8 in FIG. 3 is YES). While calculating the change rate b, the fan air volume q (= qtr) at the start of the cooling fan operation and the operation start temperature Ts (= Ttr) are set so as to be the target internal resistance change rate b (see FIG. 13). ).

  Here, the target internal resistance change rate b is the limit internal resistance value Re (predetermined resistance value, see FIG. 14) at which the battery 71 can exhibit predetermined performance, and the internal resistance change rate k of the battery 71 with a predetermined change rate. In the case where the battery 71 is used while being kept at a, the battery 71 has a set time Sd (life time) until the internal resistance value of the battery 71 reaches the limit internal resistance value Re (predetermined resistance value) after the start of use. The internal resistance value is calculated so as to be exactly the limit internal resistance value Re when the set time Sd has elapsed.

  More specifically, when the battery controller 77 determines that the internal resistance change rate k is greater than the predetermined change rate a (when determined YES in step S8 of FIG. 3), the internal resistance of the battery 71 is increased. A resistance difference ΔR (= Re−Rs) between the value Rs and the limit internal resistance value Re (corresponding to a predetermined resistance value) is calculated, and this ΔR is set for the set time from the present time (when it is determined YES in step S8). It is calculated by dividing by the time until the elapsed time (Sd−S1). That is, the target internal resistance change rate b = (Re−Rs) / (Sd−S1).

  As described above, the battery controller 77 sets the fan air volume q (= qtr) at the start of the cooling fan operation so as to achieve the calculated target internal resistance change rate b, and the operation start temperature Ts (= Ttr) is set.

  As a specific setting method, for example, the target operating temperature of the battery 71 is calculated from the average operating temperature of the battery 71 up to the current time and the internal resistance change rate k at the current time so that the target operating temperature is reached. The fan air volume qtr and the operation start temperature Ts are set. The relationship between the target operating temperature, the fan air volume qtr and the operation start temperature Ts is previously mapped by a cooling experiment or the like and stored in the memory of the battery controller 77. The fan air volume qtr and the operation start temperature Ts are Set based on the mapped data.

  As described above, in the fifth embodiment, similarly to the fourth embodiment, the battery controller 77 is configured to execute both the predetermined temperature decrease control and the air volume increase control. As the temperature of the battery 71 is higher, the cooling fan 73 is configured to increase the amount of cooling air supplied to the battery 71. Thereby, the same effect as the said Embodiment 1 thru | or Embodiment 4 can be acquired.

  In the fifth embodiment, when the internal resistance change rate k calculated based on the outputs from the battery voltage sensor 31 and the battery current sensor 32 is larger than the predetermined change rate a, the battery controller 77 is ahead of the present time. Both the predetermined temperature decrease control and the air volume increase control are executed such that the internal resistance change rate k of the battery 71 is decreased and the internal resistance value becomes the limit resistance value Re when the set time Sd elapses. It is configured as follows.

  Thereby, it is possible to prevent the cooling of the battery 71 from being excessively cooled by preventing the cooling of the battery 71 more than necessary so that the lifetime of the battery 71 exceeds the set time Sd.

  (Other Embodiments) The configuration of the present invention is not limited to the above embodiment, but includes other various configurations. That is, in each said embodiment, although the battery 71 is mounted in the motor vehicle A, it is not restricted to this, You may mount in an aircraft, a ship, etc. Further, it goes without saying that the vehicle may not be mounted on a vehicle such as an automobile A or an aircraft.

  INDUSTRIAL APPLICABILITY The present invention is useful for a battery cooling device, and is particularly useful when applied to a hybrid vehicle having an engine and at least a motor that operates by receiving power supply from the battery.

It is a block diagram which shows the structure of the hybrid vehicle carrying the battery cooling device which concerns on embodiment of this invention. It is the schematic which shows the structure of a battery cooling device. It is a flowchart which shows the cooling control process in a battery controller. It is a figure which shows the conversion map for converting an internal resistance value into a standard value. It is a figure which shows the table data of the internal resistance value after normalization memorize | stored with the date in the memory of a battery controller. It is a figure which shows the time change of an internal resistance value. It is a figure which shows the relationship between internal resistance change rate and cooling fan operation start temperature. It is a figure which shows the cooling conditions at the time of cooling control execution by a battery controller, and shows the relationship between battery temperature and the fan air volume at the time of a cooling fan operation | movement. FIG. 9 is a diagram corresponding to FIG. It is a figure which shows the relationship between the internal resistance change rate in Embodiment 2, and the fan air volume at the time of a cooling fan action | operation. FIG. 9 is a diagram corresponding to FIG. FIG. 9 is a diagram corresponding to FIG. FIG. 9 is a diagram corresponding to FIG. It is a figure which shows the mode of the change of the internal resistance value before execution of the cooling control by the battery controller in Embodiment 5, and after execution.

Explanation of symbols

a Predetermined rate of change (predetermined degree)
k Internal resistance increase (internal resistance change rate)
31 Battery voltage sensor (Internal resistance increase degree detection means)
32 Battery current sensor (Internal resistance increase degree detection means)
71 Battery 73 Cooling fan (cooling means)
76 Battery temperature sensor (battery temperature detection means)
77 Battery controller (battery cooling control means,
Internal resistance rise detection means)

Claims (5)

A battery cooling device comprising a cooling means for cooling the battery by supplying cooling air to the chargeable / dischargeable battery,
Battery temperature detecting means for detecting the temperature of the battery;
An internal resistance increase degree detecting means for detecting the internal resistance increase degree of the battery;
Battery cooling control means for supplying cooling air to the battery by the cooling means based on temperature information from the battery temperature detecting means and internal resistance information from the internal resistance increase degree detecting means,
The battery cooling control means is configured to supply cooling air to the battery by the cooling means when the battery temperature detected by the battery temperature detecting means rises above a predetermined temperature. The predetermined temperature lowering control for lowering the predetermined temperature when the internal resistance increase degree detected by the internal resistance increase degree detecting means is larger than the predetermined degree compared to when the internal resistance increase degree is less than or equal to the predetermined degree. And when the internal resistance increase degree detected by the internal resistance increase degree detecting means is larger than the predetermined degree, the cooling when the battery temperature rises is greater than when the internal resistance increase degree is less than or equal to the predetermined degree. And at least one of air volume increase control for increasing the air volume of the cooling air supplied to the battery by the means. A battery cooling apparatus, characterized in that are. The battery cooling device according to claim 1,
The battery cooling control means is configured to lower the predetermined temperature as the degree of increase in internal resistance detected by the internal resistance increase degree detection means increases when the predetermined temperature decrease control is executed. A battery cooling device. The battery cooling device according to claim 1 or 2,
The battery cooling control means supplies the battery with the cooling means when the battery temperature rises as the internal resistance increase degree detected by the internal resistance increase degree detection means increases when the air volume increase control is executed. A battery cooling device configured to increase an air volume of cooling air. The battery cooling device according to any one of claims 1 to 3,
The battery cooling control means is configured to increase the amount of cooling air supplied to the battery by the cooling means as the temperature of the battery detected by the battery temperature detecting means increases when the battery temperature rises. A battery cooling device. In the battery cooling device according to any one of claims 1 to 4,
When the battery is used while maintaining its internal resistance increase degree at the predetermined degree, the internal resistance value reaches a predetermined resistance value when a preset time elapses after the start of use,
When the internal resistance increase degree detected by the internal resistance increase degree detection means is larger than the predetermined degree, the battery cooling control means reduces the internal resistance increase degree of the battery from the present time to the set time. A predetermined temperature at the time of execution of the predetermined temperature decrease control and an air volume of the cooling air at the time of execution of the air volume increase control are set so that the internal resistance value becomes the predetermined resistance value after elapse of time. Battery cooling device.

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