JP2007048485A - Battery cooling apparatus for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery cooling apparatus for vehicle which can cool a battery effectively according to the deterioration state of the battery. <P>SOLUTION: A battery controller 6 has a deterioration measuring section 14 which determines a deterioration degree of the battery, and a driving speed measuring instrument 12 and a battery current measuring instrument 13 which detect a load of the battery for driving a vehicle, to cool the battery mounted on the vehicle. The battery controller 6 begins to cool the battery when a temperature control unit 23 extrapolates a heat generation amount of the battery from a driving speed and charge/discharge currents. The battery controller 6 can extrapolate from the heat generation amount and the present battery temperature that the battery temperature will be higher than a predetermined reference value. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle battery cooling device that cools, for example, a battery that accumulates driving power for the vehicle.

  Conventionally, as a vehicle battery cooling device that suppresses a temperature rise due to heat generation of a battery mounted on a hybrid vehicle having an engine and a motor as a drive source, for example, as described in Patent Document 1 below Technology is known.

  In such a vehicle battery cooling device, it is necessary to suppress a decrease in the input / output characteristics of the battery when the temperature rises due to heat generated by discharging and charging the battery at the start of the vehicle. In addition, it is necessary to prevent acceleration of deterioration of the battery due to use or holding in a state where the battery is in an excessively high temperature state. For this reason, conventionally, a cooling device for cooling the battery is mounted on the vehicle.

In the vehicle battery cooling device described in Patent Document 1 below, in order to prevent the battery temperature from excessively rising and to prevent deterioration in input / output characteristics and performance deterioration, the battery temperature is equal to or higher than a predetermined temperature. When it is detected that the battery has been used, the cooling device is operated to lower the battery temperature, and when the battery has been used for a predetermined period of time or longer, the cooling is performed. The device is operating to lower the battery temperature.
JP-A-9-102331

  However, in the above-described vehicle battery cooling device, the amount of heat generated by the battery is predicted from the battery temperature, the charge / discharge current, and the vehicle speed while the vehicle is running, and it is determined to start cooling the battery. At this time, a predetermined value is determined as the heat generation amount of the battery that starts cooling the battery, and cooling of the battery is started when the predicted heat generation amount exceeds the predetermined value.

  However, for example, when a lithium ion battery is used for running a vehicle, the amount of heat generation becomes large because of an increase in internal resistance and a decrease in charge capacity, which are deterioration over time. In this way, the battery starts cooling when the amount of heat generated reaches a predetermined value, even though the amount of heat generated when the battery is initially mounted is different from the amount of heat generated in a deteriorated state. It was. Therefore, the battery cooling device for a vehicle described above cannot efficiently cool the battery.

  Then, this invention is proposed in view of the situation mentioned above, and it aims at providing the battery cooling device for vehicles which can cool a battery efficiently according to the deterioration state of a battery.

  A vehicle battery cooling device according to the present invention includes a deterioration state determination unit that determines a deterioration state of a battery and a battery load that detects a load of the battery for running the vehicle in order to cool a battery mounted on the vehicle. A heat generation amount estimating means for estimating the heat generation amount of the battery from the detection means, the battery load detected by the battery load detection means, and the deterioration state determined by the deterioration state determination means; and the heat generation estimated by the heat generation amount estimation means. When the battery temperature is estimated to be higher than a predetermined reference value from the amount and the current battery temperature, the above-described problem is solved by providing a cooling unit that starts cooling the battery.

  According to the vehicle battery cooling device of the present invention, the heat generation amount of the battery is estimated from the battery load and the deterioration state of the battery, and the battery temperature is determined from the estimated heat generation amount and the current battery temperature. When it is estimated that the value is higher than the reference value, the cooling of the battery is started, so that the battery can be efficiently cooled according to the deterioration state of the battery.

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

[First Embodiment]
The present invention is applied to a battery controller 6 mounted on an electric vehicle configured as shown in FIG. 1, for example. In FIG. 1, only a part of the electric vehicle is shown.

  This electric vehicle travels by transmitting the driving force of the motor 1 to the wheels 3 via the drive shaft 2. In this electric vehicle, when driving force is generated in the motor 1, the electric power stored in the battery 5 is taken out by the inverter 4 and is supplied to the motor 1 as, for example, three-phase AC power. At this time, the electric vehicle uses the battery controller 6 to control the cooling device 7 so that the temperature of the battery falls within a predetermined temperature range, and the state of charge (SOC) that is the state of charge of the battery 5 ) Is managed within a predetermined SOC range.

  The cooling device 7 includes a blower fan that operates using the electric power charged in the battery 5, and the rotation speed is controlled by the battery controller 6 to control the cooling capacity.

  The battery controller 6 in such an electric vehicle has a functional configuration as shown in FIG. 2, and a battery temperature measuring unit 11 that measures the temperature of the battery 5 and, for example, detects the speed of the wheel 3 to detect the electric vehicle. Are connected to a traveling speed measuring section 12 that measures the traveling speed of the battery 5, a battery current measuring section 13 that measures the charge / discharge current of the battery 5, and a deterioration degree measuring section 14 that measures the deterioration state of the battery 5. The battery temperature measurement unit 11 detects the temperature of the battery 5 and outputs a temperature signal to the battery controller 6. The traveling speed measurement unit 12 detects the current traveling speed of the electric vehicle and outputs a vehicle speed signal to the battery controller 6. Further, the battery current measuring unit 13 detects a current value of power exchanged between the battery 5 and the inverter 4 and a generator (not shown), and outputs a battery current signal to the battery controller 6. Furthermore, the deterioration degree measuring unit 14 measures the degree of deterioration of the battery 5 with respect to the initial time, and outputs a deterioration measurement signal to the battery controller 6.

  The battery controller 6 includes a battery activation determination unit 21 connected to the battery temperature measurement unit 11, the traveling speed measurement unit 12, the battery current measurement unit 13, and the deterioration degree measurement unit 14, a storage unit 22, and an electric vehicle. And a temperature control unit 23 that performs cooling control of the battery 5 when the battery 5 is in operation.

  The vehicle starting determination unit 21 determines whether or not a key switch (also referred to as an ignition switch) for switching between starting and stopping of an electric vehicle (not shown) is in an on state and is starting up. When the vehicle activation determining unit 21 determines that the ignition switch is on, the vehicle activation determining unit 21 detects the temperature signal from the battery temperature measurement unit 11 and the vehicle speed signal from the travel speed measurement unit 12. The battery current signal from the battery current measurement unit 13 and the deterioration measurement signal from the deterioration degree measurement unit 14 are supplied to the temperature control unit 23.

  The storage unit 22 stores various parameters for controlling the temperature of the battery 5 and the like during startup of the electric vehicle. Various parameters stored in the storage unit 22 correspond to a reference value related to temperature for determining whether or not to operate the cooling device 7 to be described later, the charge / discharge current of the battery 5, the vehicle speed, and the degree of deterioration of the battery 5. This is the reference value for the amount of heat generated.

  The temperature control unit 23 is configured to measure the temperature signal from the battery temperature measurement unit 11, the vehicle speed signal from the travel speed measurement unit 12, the battery current signal from the battery current measurement unit 13, and the degree of deterioration measurement via the vehicle activation determination unit 21. The deterioration measurement signal from the unit 14 is input to control the operation of the cooling device 7 in order to control the temperature of the battery 5. Thereby, the temperature control unit 23 prevents the battery 5 from becoming excessively hot and reducing the input / output characteristics.

  Further, the temperature control unit 23 is mounted on the electric vehicle according to the degree of deterioration obtained by the deterioration degree measuring unit 14 from the internal resistance of the battery 5 or the usage time after the battery 5 is mounted on the electric vehicle. It is determined how much the degree of deterioration has progressed from the initial degree of deterioration of 0%. As will be described later, it is determined whether the cooling device 7 needs to be turned on in consideration of the degree of deterioration.

  Next, the cooling control processing of the battery 5 for preventing the temperature of the battery 5 from becoming excessively high during startup of the electric vehicle by the battery controller 6 as described above will be described with reference to the flowchart of FIG. To do. 3 is repeatedly executed at predetermined intervals when it is determined by the vehicle activation determining unit 21 that the electric vehicle is activated.

  In the cooling control process for the battery 5, first, in step S <b> 1, the battery controller 6 inputs a temperature signal from the battery temperature measurement unit 11 to the temperature control unit 23, and stores the current temperature of the battery 5 in the storage unit 22. It is compared with the reference value T0 stored in advance, and it is determined whether or not the current temperature of the battery 5 is equal to or lower than the reference value T0. As shown in FIG. 4, the reference value T0 is a temperature of the battery 5 that is smaller than a reference value T1 that turns on a cooling device 7 described later and a reference value T2 that turns the cooling device 7 off. The minimum temperature that can be allowed to cool is set. If it is determined that the temperature of the battery 5 is equal to or lower than the reference value T0, the process ends. If it is determined that the temperature of the battery 5 is not equal to or lower than the reference value T0, the process proceeds to step S2.

  Next, in step S2, the battery controller 6 compares the current battery temperature with a reference value T1 stored in advance in the storage unit 22, and determines whether or not the current battery temperature is equal to or higher than the reference value T1. judge. As shown in FIG. 4, the reference value T1 is a battery temperature at which the battery 5 may become hot and input / output characteristics may deteriorate, and the cooling device 7 needs to be transitioned from an on state to an off state. It is set by an experiment using the battery 5 in advance. If the current battery temperature is equal to or higher than the reference value T1, the cooling device 7 is controlled to be turned on in step S3. If the current battery temperature is not equal to or higher than the reference value T1, the process proceeds to step S4. .

  Next, in step S <b> 4, the battery controller 6 estimates the amount of heat generated by the battery 5 from the vehicle speed signal from the travel speed measurement unit 12 and the deterioration measurement signal from the deterioration degree measurement unit 14 by the temperature control unit 23. And the temperature control part 23 determines whether battery temperature becomes reference value T1 from the said emitted-heat amount and the present battery temperature. If it is estimated that the battery temperature is equal to or higher than the reference value T1, the cooling device 7 is turned on in step S3. If it is estimated that the battery temperature is not higher than the reference value T1, the process proceeds to step S5. Proceed with the process.

  Here, for example, when the degree of deterioration of the predetermined battery 5 and the predetermined battery temperature are satisfied, as shown in FIG. 5, when the vehicle speed of the electric vehicle is as high as V1, the amount of heat generated is estimated based on the vehicle speed. When the battery temperature becomes the reference value T1 and the cooling device 7 is turned on, the battery temperature based on the calorific value estimated based on the vehicle speed becomes the reference value T2 when the vehicle speed becomes as low as V2, and the cooling device 7 is turned off.

  The vehicle speed V1 at which the battery temperature is equal to or higher than the reference value T1 and the vehicle speed V2 at which the battery temperature is not equal to or higher than the reference value T1 vary depending on the current battery temperature and the degree of deterioration of the battery 5. The explanation for estimating the amount of heat generated based on the vehicle speed according to the degree of deterioration of the battery 5 will be given in step S5.

  In addition, as shown in FIG. 6, the actual vehicle speed has a large change allowance during traveling of the electric vehicle, and the vehicle temperature V1 at which the heat generation amount becomes large and the battery temperature becomes equal to or higher than the reference value T1, and the heat generation amount is small and the battery temperature. Frequently changes between the vehicle speed V2 and the vehicle speed V2 that does not exceed the reference value T1. On the other hand, in step S4, the temperature control unit 23 sets the average value of the vehicle speed signal input during a predetermined unit time as the vehicle speed used for estimating the heat generation amount. Thereby, the change in the vehicle speed shown in FIG. 6 is converted into a moving average of the vehicle speed as shown in FIG. Thus, the actual vehicle speed is prevented from frequently changing between the vehicle speed V1 and the vehicle speed V2, and the on / off control of the cooling device 7 is stably switched.

  Next, in step S <b> 5, the battery controller 6 estimates the amount of heat generated by the battery 5 from the battery current signal from the battery current measurement unit 13 and the deterioration measurement signal from the deterioration degree measurement unit 14 by the temperature control unit 23. And the temperature control part 23 determines whether battery temperature becomes reference value T1 from the said emitted-heat amount and the present battery temperature. If it is estimated that the battery temperature is equal to or higher than the reference value T1, the cooling device 7 is turned on in step S3. If it is estimated that the battery temperature is not equal to or higher than the reference value T1, the process proceeds to step S6. Proceed with the process.

  Here, for example, when the degree of deterioration of the predetermined battery 5 and the predetermined battery temperature are satisfied, as shown in FIG. 8, when the charge / discharge current of the battery 5 is as high as I1, it is estimated based on the charge / discharge current. When the battery temperature by the generated heat amount becomes the reference value T1 and the cooling device 7 is turned on, while the charge / discharge current of the battery 5 becomes as low as I2, the heat generation amount estimated based on the charge / discharge current Becomes the reference value T2, and the cooling device 7 is turned off.

  The charge / discharge current I1 at which the battery temperature is equal to or higher than the reference value T1 and the charge / discharge current I2 at which the battery temperature is not equal to or higher than the reference value T1 vary depending on the current battery temperature and the degree of deterioration of the battery 5. .

  In addition, as shown in FIG. 9, the actual charge / discharge current changes when the absolute value is taken, and the change allowance is large during the running of the electric vehicle, the heat generation amount becomes large, and the battery temperature becomes the reference value T1 or more. The charging / discharging current I1 frequently changes between the charging / discharging current I1 and the charging / discharging current I2 that generates a small amount of heat and the battery temperature does not exceed the reference value T1. On the other hand, in step S5, the temperature control unit 23 uses the average value of the battery current signals input during a predetermined unit time as the battery current signal used for estimating the heat generation amount. Thereby, the change of the charging / discharging current shown in FIG. 9 is converted into a moving average of the charging / discharging current as shown in FIG. Thereby, it is suppressed that charging / discharging current changes frequently between charging / discharging current I1 and charging / discharging current I2, and the control of ON / OFF of the cooling device 7 is switched stably.

  In addition, as shown in FIG. 11, the amount of heat generated with respect to the charge / discharge current (average current) of the battery 5 is small because the internal resistance is small at the initial stage (deterioration degree: 0%) when the battery 5 is mounted on an electric vehicle. However, as the deterioration degree of the battery 5 increases to 20%, 40%, and 80%, the internal resistance increases and gradually increases. Further, when the charge / discharge current is small, the degree of influence on the heat generation amount due to the deterioration degree of the battery 5 is small, but as the charge / discharge current increases, the sensitivity of the heat generation amount with respect to the deterioration degree of the battery 5 increases. There is a big difference in calorific value compared to.

  In this way, when the calorific value changes depending on the degree of deterioration of the battery 5, the battery temperature becomes the reference value T1, and the calorific value that satisfies the condition for turning on the cooling device 7 is Q1, as shown in FIG. At the initial stage of 5, the calorific value Q1 is not reached unless the charge / discharge current has a large value such as A1. On the other hand, as the degree of deterioration of the battery 5 increases to 40% and 80%, the charge / discharge current at which the heat generation amount reaches Q1 gradually decreases to A2 and A3.

  Therefore, as shown in FIG. 13, the temperature control unit 23 indicates that the degree of deterioration of the battery 5 is 0%, as shown in FIG. In some cases, the charging / discharging current I1 is set to A1, and when the charging / discharging current detected by the battery current measuring unit 13 exceeds A1, the cooling device 7 is turned on in step S3. Similarly, when the deterioration degree of the battery 5 is 40%, the temperature control unit 23 sets the charging / discharging current I1 to A2 smaller than A1, and the charging / discharging detected by the battery current measuring unit 13 is set. If the current exceeds A2, the cooling device 7 is turned on in step S3. If the deterioration degree of the battery 5 is 80%, the charge / discharge current I1 is set to A3 smaller than A1 and A2. If the charge / discharge current detected by the battery current measuring unit 13 exceeds A3, the cooling device 7 is turned on in step S3.

  Then, after the cooling device 7 is turned on in step S3, the temperature control unit 23 of the battery controller 6 inputs a temperature signal from the battery temperature measurement unit 11, and the current battery temperature causes the cooling device 7 to be turned on. The heat generation amount of the battery 5 is estimated from the determination of whether or not the reference value T2 is equal to or less than the reference value T2 to be turned off (step S6), the vehicle speed signal from the traveling speed measurement unit 12, and the degree of deterioration of the battery 5, and the heat generation amount It is determined whether or not the temperature of the battery 5 based on the current battery temperature is equal to or lower than the reference value T2 (step S7), the battery current signal from the battery current measuring unit 13 and the degree of deterioration of the battery 5 The heat generation amount is estimated, and it is determined whether or not the temperature of the battery 5 based on the heat generation amount and the current battery temperature is equal to or lower than the reference value T2 (step S8).

  In any of the determinations of step S6, step S7, and step S8, when it is determined that the battery temperature does not become the reference value T2 or less, the cooling device 7 is kept on and the process ends. On the other hand, if it is determined in step S6, step S7, and step S8 that the battery temperature is all equal to or lower than the reference value T2, the cooling device 7 is controlled to be turned off in step S9, and the process ends.

[Effect of the first embodiment]
As described above in detail, according to the battery controller 6 according to the first embodiment to which the present invention is applied, the battery 5 is determined from the battery load such as the charge / discharge current and the vehicle speed of the battery 5 and the deterioration state of the battery 5. Since the heat generation amount is estimated and the battery temperature is estimated to be higher than the predetermined reference value T2 from the estimated heat generation amount and the current battery temperature, the battery 5 starts to be cooled. The battery can be efficiently cooled according to the state. That is, regardless of the deterioration state of the battery 5, the cooling is not started in spite of the fact that the heat generation amount actually increases due to the deterioration as in the case of starting the cooling when the predetermined heat generation amount is reached. In addition, since it has not actually deteriorated, it can be avoided that the cooling is started even though the heat generation amount is small.

  Therefore, according to the battery controller 6, the battery 5 can be reliably cooled when the amount of heat generation increases due to deterioration, while the cooling device 7 is excessive when the amount of heat generation is small because the deterioration does not progress. By avoiding driving, power can be saved.

  Moreover, according to this battery controller 6, since the average value of the charging / discharging current of the battery 5 input in a predetermined unit time is detected as the load of the battery 5 and the heat generation amount of the battery 5 is estimated, The device 7 can be driven on and off stably. That is, even when the charge / discharge current I1 for starting cooling and the charge / discharge current I2 for ending cooling are set and hysteresis is set for the charge / discharge current as shown in FIG. Since the change allowance is large, it is difficult to set the charge / discharge current I1 and the charge / discharge current I2, and the battery 5 may not be sufficiently cooled. On the other hand, by estimating the calorific value of the battery 5 using the average value of the charging / discharging current, it is detected that the charging / discharging current has fluctuated beyond the charging / discharging current I1 and the charging / discharging current I2, On / off control of the cooling device 7 can be performed.

  Furthermore, according to the battery controller 6, since the average value of the vehicle speed input per predetermined unit time is detected as the load of the battery 5 and the heat generation amount of the battery 5 is estimated, the cooling device 7 is stabilized. And can be turned on and off. That is, as shown in FIG. 5, even when the vehicle speed V1 for starting cooling and the vehicle speed V2 for ending cooling are set and hysteresis for the charge / discharge current is set, the change speed of the vehicle speed is large. In addition, it is difficult to set the vehicle speed V1 and the vehicle speed V2, and the battery 5 may not be sufficiently cooled. On the other hand, by estimating the calorific value of the battery 5 using the average value of the vehicle speed, it is detected that the vehicle speed has fluctuated beyond the vehicle speed V1 and the vehicle speed V2, and the on / off control of the cooling device 7 is performed. be able to.

  In this way, the battery controller 6 can estimate the amount of heat generated by the battery 5 based on the vehicle speed or the average value of the charge / discharge current, so that the input / output power of the battery 5 can be reduced due to insufficient cooling. Thus, it is possible to avoid the problem that the deterioration of the battery 5 is advanced.

[Second Embodiment]
Next, the battery controller 6 according to the second embodiment will be described. In addition, about the part similar to the above-mentioned 1st Embodiment, the detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  As shown in FIG. 14, the battery controller 6 according to the second embodiment is connected to a navigation unit 31 that sets a traveling course based on the positional relationship between the destination set in the electric vehicle and the current location. The navigation unit 31 supplies the battery controller 6 with information for determining a driving load such as legal speed information and road gradient information set for each road link constituting the driving course.

  As shown in FIG. 15, the battery controller 6 first has a travel course designated in the navigation unit 31 in step S <b> 11 and information indicating the travel course is supplied in step S <b> 12. The temperature controller 23 calculates the amount of heat generated by the battery 5 when traveling on the traveling course.

  In step S12, the temperature control unit 23 inputs legal speed information and road gradient information in units of road links constituting the travel course, and travels in units of road links or a predetermined number of consecutive road link groups (sections). Find the load.

  As shown in FIG. 16, the battery 5 has a characteristic that, for example, in the initial state (deterioration degree: 0%), the heat generation amount increases as the vehicle speed increases. As the vehicle speed and road gradient increase, the value of the correction coefficient for correcting the heat generation amount shown in FIG. 16 increases. This correction coefficient can be determined as α, for example, when the vehicle speed is V and the climbing road is 2%. The temperature control unit 23 can obtain the heat generation amount of the battery 5 when traveling on a 2% uphill road at the vehicle speed V by multiplying the heat generation amount for the vehicle speed V shown in FIG. Further, since the amount of heat generated by the battery 5 varies depending on the degree of deterioration, a correction coefficient β for the degree of deterioration X (%) of the battery 5 is obtained as shown in FIG.

  Then, the temperature control unit 23 multiplies the initial heat generation amount of the battery 5 by the correction coefficient α obtained from the vehicle speed and the road gradient and the correction coefficient β obtained from the deterioration degree, and is estimated from the traveling load and the deterioration degree. The amount of generated heat can be determined.

  Next, when the battery controller 6 determines in step S13 that the electric vehicle has started traveling along the traveling course specified in step S11, the battery activation determination unit 21 determines that the temperature controller 23 in step S14. From the temperature signal from the battery temperature measuring unit 11, it is determined whether or not the battery temperature is equal to or higher than the reference value T0. If it is determined that the battery temperature is not equal to or higher than the reference value T0, the process is terminated while the cooling device 7 is turned off in step S21, while the battery temperature is determined to be equal to or higher than the reference value T0. Advances the process to step S15.

  In step S15, the temperature control unit 23 receives information indicating a section (road link) in which the electric vehicle is currently traveling, for example, from the navigation unit 31, and is estimated in a section next to the section (road link). Determine the amount of heat generated.

  Next, in step S16, the temperature control unit 23 estimates the battery temperature when the amount of heat generated in step S15 occurs when the vehicle travels in the next section at the current battery temperature detected in step S14. At this time, the temperature control unit 23 adds the current battery temperature and the temperature increase corresponding to the estimated heat generation amount to estimate the battery temperature in the next section.

  Next, in step S17, the temperature control unit 23 determines whether or not the battery temperature estimated in step S16 is equal to or higher than the reference value T2, and if it is determined that the battery temperature is not equal to or higher than the reference value T2, the cooling device 7 is determined in step S21. Is turned off, and if it is determined that the value is equal to or greater than the reference value T2, the process proceeds to step S18.

  Next, in step S18, the temperature control unit 23 determines the duty ratio for driving the cooling device 7 from the estimated battery temperature equal to or higher than the reference value T2. At this time, the temperature control unit 23 increases the cooling capacity (cooling degree) for the battery 5 by driving the cooling device 7 with a higher duty ratio as the difference between the estimated battery temperature and the reference value T2 is larger.

  Next, in step S19, the temperature control unit 23 drives the cooling device 7 with the duty ratio determined in step S18 to cool the battery 5. In step S19, the cooling device 7 is driven for a predetermined time with the determined duty ratio.

  Next, in step S20, the temperature control unit 23 decreases the temperature signal from the battery temperature measurement unit 11, and the temperature increase corresponding to the current battery temperature that has decreased and the amount of heat generated in the next section obtained in step S15. The degree is added to determine whether or not the battery temperature is equal to or lower than the reference value T1. If it is determined that the battery temperature estimated in the next section has become equal to or lower than the reference value T1, the cooling device 7 is turned off in step S21. If not, the process proceeds to step S14. return.

  In the battery controller 6 that performs such an operation, for example, as shown in FIG. 19, the relationship between the travel distance and the estimated calorific value is estimated in step S15 in the sections a, b, and c. It is estimated in step S17 that the heat generation amount of the battery 5 is high and the battery temperature estimated in step S16 is equal to or higher than the reference value T2. That is, it is estimated that the battery temperature is equal to or higher than the reference value T2 in the next section of the sections a, b, and c.

  On the other hand, the battery controller 6 drives the cooling device 7 with a duty ratio of 25% according to the degree to which the battery temperature based on the calorific value estimated in the section a exceeds the reference value T2, and the battery temperature in the section a. The battery 5 is cooled so that becomes equal to or less than the reference value T1. In section b, the cooling device 7 is driven with a duty ratio of 50%, and in section c, the cooling apparatus 7 is driven with a duty ratio of 100%.

  As a result, even when the load on the traveling course on which the electric vehicle travels is high and the charging / discharging current of the battery 5 is high, the battery temperature is set to the reference value T1 or less in advance and the battery in the section where the traveling load is high. It can be avoided that the temperature becomes equal to or higher than the reference value T2.

[Effects of Second Embodiment]
As described above in detail, according to the battery controller 6 according to the second embodiment to which the present invention is applied, the load of the battery 5 is predicted for each predetermined section in the traveling course, and the predicted predetermined section is determined. Using the battery load, the amount of heat generated by the battery 5 is predicted for each predetermined section, and cooling of the battery 5 is started in a section before the predetermined section where the battery temperature is predicted to be higher than the reference value T2. Therefore, the temperature of the battery 5 can be lowered before traveling in a section where the temperature of the battery 5 increases. Therefore, when the battery temperature actually increases, the temperature rise degree of the battery 5 exceeds the cooling capacity of the cooling device 7, and the input / output power of the battery 5 decreases due to insufficient cooling, It is possible to avoid the problem that the deterioration of the battery 5 is advanced.

  Further, according to the battery controller 6, the greater the degree that the battery temperature becomes higher than the reference value T <b> 2, the higher the duty ratio of the cooling device 7 and the higher the degree of cooling. It is possible to avoid exceeding T2.

  The above-described embodiment is an example of the present invention. For this reason, the present invention is not limited to the above-described embodiment, and various modifications can be made depending on the design and the like as long as the technical idea according to the present invention is not deviated from this embodiment. Of course, it is possible to change.

It is a block diagram which shows the structure of the electric vehicle provided with the battery controller which concerns on 1st Embodiment to which this invention is applied. It is a block diagram which shows the structure of the battery controller which concerns on 1st Embodiment to which this invention is applied. It is a flowchart which shows the operation | movement procedure which controls a cooling device with the battery controller which concerns on 1st Embodiment to which this invention is applied. It is a figure which shows the relationship between the battery temperature which makes a cooling device an ON state, and the battery temperature which makes a cooling device an OFF state. It is a figure which shows the relationship between the vehicle speed which makes a cooling device an ON state, and the vehicle speed which makes a cooling device an OFF state. It is a figure which shows the change of the vehicle speed in driving | running | working. It is a figure which shows the moving average of the vehicle speed obtained by calculating the average value of a vehicle speed for every predetermined time. It is a figure which shows the relationship between the charging / discharging current which makes a cooling device an ON state, and the charging / discharging current which makes a cooling device an OFF state. It is a figure which shows the change of the charging / discharging electric current during driving | running | working. It is a figure which shows the moving average of the charging / discharging electric current obtained by calculating the average value of charging / discharging electric current for every predetermined time. It is the figure which showed the relationship between the charging / discharging electric current of a battery, and the emitted-heat amount for every deterioration degree of a battery. It is a figure for demonstrating the relationship between the charging / discharging electric current of a battery, and the emitted-heat amount for every deterioration degree of a battery, and explaining the difference in charging / discharging electric current when it becomes predetermined | prescribed calorific value. It is a figure which shows the relationship between the deterioration degree of a battery, and charging / discharging electric current. It is a block diagram which shows the structure of the battery controller which concerns on 2nd Embodiment to which this invention is applied. It is a flowchart which shows the operation | movement procedure which controls a cooling device with the battery controller which concerns on 2nd Embodiment to which this invention is applied. It is a figure which shows the relationship between the vehicle speed and the emitted-heat amount in the initial stage when the battery has not deteriorated. It is the figure which showed the relationship between a vehicle speed and the correction coefficient of the emitted-heat amount for every road gradient. It is a figure which shows the relationship between the deterioration degree of a battery, and the correction coefficient of the emitted-heat amount. It is a figure which shows the relationship between the emitted-heat amount estimated in the driving | running | working course, and the duty ratio of a cooling device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Drive shaft 3 Wheel 4 Inverter 5 Battery 6 Battery controller 7 Cooling device 11 Battery temperature measurement part 12 Traveling speed measurement part 13 Battery current measurement part 14 Deterioration degree measurement part 21 Vehicle starting determination part 22 Storage part 23 Temperature control part 31 Navigation unit

Claims (5)

In a vehicle battery cooling device for cooling a battery mounted on a vehicle,
A deterioration state determining means for determining a deterioration state of the battery;
Battery load detecting means for detecting a load of the battery for running the vehicle;
A calorific value estimating means for estimating a calorific value of the battery from the battery load detected by the battery load detecting means and the deterioration state determined by the deterioration state determining means;
Cooling means for starting cooling of the battery when the battery temperature is estimated to be higher than a predetermined reference value from the heat generation amount estimated by the heat generation amount estimation means and the current battery temperature. A vehicle battery cooling device. The battery load detecting means detects an average value of charge / discharge currents of the battery input in a predetermined unit time as the battery load,
The vehicular battery cooling device according to claim 1, wherein the calorific value estimation means estimates the calorific value of the battery using an average value of charge / discharge currents of the battery. The battery load detecting means detects an average value of the vehicle speed input in a predetermined unit time as the battery load,
The vehicle battery cooling device according to claim 1, wherein the heat generation amount estimation means estimates the heat generation amount of the battery using an average value of the vehicle speed. The battery load detection means predicts the battery load for each predetermined section in a travel course in which the vehicle travels,
The heat generation amount estimation means predicts the heat generation amount of the battery for each predetermined section using the predicted battery load for each predetermined section,
The cooling means cools the battery in a section before a predetermined section where the battery temperature is predicted to be higher than a reference value based on the heat generation amount predicted by the heat generation amount estimation means and the battery temperature. The vehicle battery cooling device according to claim 1, wherein the vehicle battery cooling device is started. 2. The vehicle according to claim 1, wherein the cooling unit increases the degree of cooling as the heat generation amount predicted by the heat generation amount estimation unit is high and the battery temperature exceeds a reference value. Battery cooling device.

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