JP6910979B2 - Secondary battery temperature control system and temperature control method - Google Patents

Description

The present invention relates to a temperature control system and a temperature control method for a secondary battery, and is particularly suitable for application to a temperature control system and a temperature control method for controlling the temperature of a secondary battery for a railway vehicle.

In order to prevent global warming, it is required to reduce carbon dioxide emissions. For example, for automobiles that use a gasoline engine, which is one of the major sources of carbon dioxide emissions, go to hybrid electric vehicles and electric vehicles. Is being replaced. Here, as the storage battery (secondary battery) capable of charging and discharging, there are a lithium ion secondary battery, a nickel hydrogen battery, a lead battery, an electric double layer capacitor and the like. Of these, in particular, a secondary battery system having a plurality of high output density battery cells such as a lithium ion battery is widely used for industrial applications, and in recent years, a secondary battery system for vehicles having a high voltage and a large capacity has been used. Is beginning to spread.

Also, in the field of railway vehicles, secondary battery systems are widely used in order to save energy. Specific applications of secondary battery systems in the field of railway vehicles include hybrid railway vehicles that supply power to motors by combining a generator driven by a diesel engine and a secondary battery system, and electric vehicles. A train system that absorbs the regenerative power into a secondary battery when there is no regenerative load, and a hybrid train that uses a train line and a secondary battery system for the purpose of eliminating overhead lines (the secondary battery system is used as a power source between stations). And charge the secondary battery system at the station).

A large secondary battery system represented by a power source for powering an automobile or a railroad vehicle as described above is required to have a high output and a large capacity. Therefore, in general, a plurality of battery cells are connected in series and parallel. It is composed. Further, a lithium ion battery is often used for each battery cell.

Here, in general, the specifications of a secondary battery are defined as an usable temperature range that guarantees operation as a safe product or an operating temperature range that can satisfy a predetermined performance. Operating the secondary battery beyond the upper and lower limits of the temperature range according to these specifications may cause the battery system to fail and shorten the life of the battery system, and must be avoided. In general, a secondary battery such as a lithium-ion battery deteriorates at an accelerated rate each time it is stored at a high temperature or charged / discharged, and the battery capacity decreases and the internal resistance increases to cause fluctuations in output. In addition, charging and discharging at low temperature also accelerates deterioration.

As described above, temperature control is an important matter in the battery system. For example, in Patent Document 1, the temperature rise of the secondary battery is predicted by predicting the operation pattern of the motor based on the road surface gradient information of the planned traveling route of the automobile. A control technique for operating a cooling fan by setting a cooling schedule so as not to exceed the upper limit temperature is disclosed.

Japanese Unexamined Patent Publication No. 2015-0707722

However, the driving pattern of a car (motor) is actually caused by various factors such as road congestion, traffic light stop, road surface condition, wind direction, usage of air conditioner, driver's habit and fatigue, etc. When the operation pattern is calculated based only on the road surface gradient information as in Patent Document 1, it is inevitable that the prediction accuracy of the temperature rise of the secondary battery will decrease. In addition, in order to predict the temperature rise of the secondary battery mounted on the automobile, the planned travel route is determined, the road surface gradient information is obtained, the motor operation pattern is calculated based on the road surface gradient information, and the motor operation pattern is used. It is necessary to take complicated steps of calculating the charge / discharge pattern of the secondary battery and then predicting the heat generation / temperature rise of the secondary battery based on the charge / discharge pattern of the secondary battery, which increases the calculation load.

From the above, with the control technology disclosed in Patent Document 1, it is difficult to control the temperature of the secondary battery based on the highly accurate heat generation prediction of the secondary battery while suppressing the calculation load. was there.

Further, in the control technique disclosed in Patent Document 1, although a cooling control method for suppressing deterioration due to exposure of the secondary battery to a high temperature is disclosed, the secondary battery is charged and discharged at a low temperature. There is also a problem that the control method for suppressing the deterioration due to the above-mentioned is not disclosed, and the effect of suppressing the deterioration of the secondary battery is not sufficient.

On the other hand, in hybrid railroad vehicles, buses equipped with secondary batteries, transportation vehicles in factories, etc., secondary batteries mounted on moving bodies (vehicles) for which operation schedules and operation routes are defined, and power peaks. For stationary secondary batteries for shift use and secondary batteries that are being charged quickly, the charge / discharge pattern of the secondary batteries is almost fixed, so special (complex) calculations are performed as in the automobiles described above. Even if it is not, it is possible to accurately predict the heat generation and temperature rise of the secondary battery.

The present invention has been made in consideration of the above points, and is a temperature control system and a temperature control method for a secondary battery that enable stable long-term use of the secondary battery by appropriately controlling the temperature. We are trying to propose a secondary battery temperature control system and temperature control that are effective for secondary battery systems that are used in applications where the operation pattern is generally fixed, such as for railway vehicles. It is an attempt to propose a method.

In order to solve such a problem, the present invention is a temperature control system for a secondary battery that adjusts the temperature of a secondary battery mounted on a vehicle to a reference temperature by controlling the operation of a predetermined temperature control device. A first indicating a correspondence relationship between a control unit that controls the operation of the temperature adjusting device, position information or time information relating to the vehicle, and at least one of charge / discharge current, charge / discharge power, or heat generation amount of the secondary battery. A temperature control system including the above data table and a second data table showing the correspondence between the amount of heat removed, which means the amount of heat removed from the secondary battery, and the output of the temperature adjusting device is provided. In this temperature control system, the control unit calculates the calorific value of the secondary battery within a predetermined time based on the first data table by inputting the position information or the time information obtained for the vehicle. Then, based on the calculated calorific value, the detection temperature of the secondary battery, and the temperature difference between the reference temperature, the heat removal amount within the predetermined time is calculated, and the calculated heat removal amount is used as an input. The output of the temperature adjusting device is calculated based on the second data table, and the temperature adjusting device is operated based on the calculated output.

Further, in order to solve such a problem, in the present invention, the temperature control system of the secondary battery for adjusting the temperature of the secondary battery mounted on the vehicle to the reference temperature by controlling the operation of the predetermined temperature adjusting device is used. A method for controlling the temperature of the next battery is provided. In this temperature control method, the temperature control system of the secondary battery includes a control unit that controls the operation of the temperature adjusting device, position information or time information regarding the vehicle, and charge / discharge current and charge / discharge of the secondary battery. A first data table showing a correspondence relationship with at least one of electric power or a calorific value, and a second data table showing a correspondence relationship between a heat removal amount meaning the amount of heat removed from the secondary battery and an output of the temperature adjusting device. It has a data table and. Then, in this temperature control method, the heat generation amount of the secondary battery within a predetermined time is calculated based on the first data table by inputting the position information or the time information obtained for the vehicle. 2. The second heat removal amount within the predetermined time is calculated based on the heat generation amount calculated in the first step, the detection temperature of the secondary battery, and the temperature difference of the reference temperature. Calculated in the third step and the third step of calculating the output of the temperature adjusting device based on the second data table by inputting the step and the heat removal amount calculated in the second step. It is characterized by comprising a fourth step of operating the temperature adjusting device based on the output.

According to the present invention, there is provided a temperature control system and a temperature control method for a secondary battery, which enables stable long-term use of the secondary battery by appropriately controlling the temperature.

It is a block diagram which shows the structural example of the temperature control system 1 which concerns on 1st Embodiment of this invention, and its control flow. It is a figure which shows an example of the table 13. It is a block diagram which shows the structural example of the temperature control system 2 which concerns on 2nd Embodiment of this invention, and the control flow thereof. It is a block diagram which shows the structural example of the temperature control system 3 which concerns on 3rd Embodiment of this invention, and the control flow thereof. It is a figure which shows an example of the table 32. It is a block diagram which shows the structural example of the temperature control system 4 which concerns on 4th Embodiment of this invention, and the control flow thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to drawings and the like. The following description shows specific examples of the contents of the present invention, and the present invention is not limited to these explanations. It can be changed and modified. Further, in all the drawings for explaining the present invention, those having the same function may be designated by the same reference numerals, and the repeated description thereof may be omitted. Further, in the following, the secondary battery (storage battery) may be simply abbreviated as "battery".

(1) Configuration of First Embodiment (1-1) FIG. 1 is a block diagram showing a configuration example of the temperature control system 1 according to the first embodiment of the present invention and its control flow. In the present embodiment, the temperature control system 1 will be described as an example of controlling the temperature of a battery mounted on a railroad vehicle in which a predetermined operation is performed.

As shown in FIG. 1, the temperature control system (Temperature Control System) 1 according to the first embodiment has a function of controlling the operation of the temperature control device (Fan) 5, and is a control unit (Controller). It is configured to include 11, a reference temperature data (Tref) 12, a table (Table_A) 13, and a table (Table_B) 14. The temperature adjusting device 5 is a device for adjusting the temperature of a battery mounted on a railway vehicle, and is, for example, a blower fan.

The control unit 11 is, for example, a CPU or a control circuit, and is based on information input outside the system (temperature sensor 61 or position sensor 62) or information held in the system (reference temperature data 12, tables 13, 14). By performing a predetermined calculation and performing a control process for controlling the operation of the temperature adjusting device 5 based on the calculation result, the temperature control of the battery is realized. The details of the control process will be described later.

The reference temperature data 12 is data indicating a reference temperature “Tref” which is a target temperature for temperature control of the battery during charging / discharging, and in the first embodiment, the reference temperature Tref is a predetermined fixed value. be.

Table 13 is a data table showing the correspondence between the position x and time t of the railroad vehicle, the charge / discharge current (current I), the charge / discharge power (electric power P), and the calorific value Q in the battery. The vehicle position x, which will be described later, has the same meaning as the position x of the railroad vehicle on the table 13. Further, the table 13 may show the correspondence between at least one of the vehicle position x or the time t and at least one of the current I, the electric power P, or the calorific value Q.

The table 14 is a data table showing the correspondence relationship between the heat removal amount S calculated by the control unit 11 and the output (Fan Output) of the temperature adjusting device 5. More specifically, the table 13 shows the correspondence between the output of the temperature adjusting device 5 (blower fan) and the amount of heat removed from the battery per unit time. Although the details will be described later, the heat removal amount S is calculated by the control unit 11. Further, among the correspondences shown in the table 14, the heat removal amount S may indicate the heat removal amount of the battery per unit time.

Further, according to FIG. 1, a temperature sensor (Sensor_A) 61 and a position sensor (Sensor_B) 62 are provided outside the temperature control system 1. The temperature sensor 61 is a sensor provided in the battery cell or module to detect the temperature of the battery, and inputs the detected battery temperature "Tcell" to the temperature control system 1. The position sensor 62 is a sensor that detects the position of a railroad vehicle, and inputs the detected vehicle position (x) to the temperature control system 1.

(1-2) Control processing In the following, the control processing by the control unit 11 for controlling the operation of the temperature adjusting device 5 will be described in detail with reference to an example of a detailed calculation method.

First, as the first step of the control process, the control unit 11 calculates the difference (temperature difference ΔTcr) between the reference temperature Tref shown in the reference temperature data 12 and the battery temperature Tcell input from the temperature sensor 61. Hereinafter, the temperature difference ΔTcr will be described as being calculated by “Tcell-Tref”.

Next, as a second step of the control process, the control unit 11 collates the table 13 based on the vehicle position x input from the position sensor 62, so that the period from the current time to the elapse of a predetermined time. The calorific value in (within a predetermined time) (the calorific value "Q_km" at the position or time corresponding to the order k to the order k + m, which will be described later) is calculated. The execution order of the first step and the second step may be reversed or may be parallel.

Here, the second step of the control process will be described in detail. FIG. 2 is a diagram showing an example of the table 13. The table 13 illustrated in FIG. 2 is composed of items 131 to 136.

In item 131, the order "k" of the data arrangement is described (k = 0,1, ..., N), and items 132 to 136 are described in a form corresponding to each order k. Specifically, the vehicle position "x (k)" is described in the item 132, the time "t (k)" is described in the item 133, and the battery current "I (k)" is described in the item 134. In the item 135, the electric power “P (k)” of the battery is described, and in the item 136, the calorific value “Q (k)” of the battery is described.

The vehicle position x (k) may be expressed by a combination of longitude and latitude, or may be expressed by a distance from a reference point (for example, the starting station) when the movement route is fixed like a railroad vehicle. good.

The time t (k) may be simply expressed as a time, or may be expressed as an elapsed time from the departure time of the first train station. Further, when the operation schedule is disturbed, the time t (k) in the table 13 may be corrected by using the information on the delay time. For example, when a railroad vehicle stops at a station at position x (m) for a time Δt longer than usual, the delay can be dealt with by adding Δt for the time t (k) after m + 1. can. In this description, it is assumed that the control unit 11 has a time timing function.

Further, a plurality of tables 13 as illustrated in FIG. 2 may be prepared. For example, in the case of a railroad vehicle, tables 13 starting from each stop station can be prepared for the number of stops, and the distance from the departure station can be expressed as position information (vehicle position x (k)) in each table 13. can. In this case, it is possible to more flexibly deal with the deviation between the current time and the time information (time t (k)) in the table 13 due to the disturbance of the operation schedule.

Then, as shown in FIG. 2, when the calorific value Q (k) of the item 136 is described in the table 13, each of the order k corresponding to the current time to the order k + m corresponding to the predetermined time Since the calorific value Q (k) to Q (k + m) of the battery are described, the control unit 11 can calculate the calorific value "Q_km" within a predetermined time by a simple method of obtaining the sum of these. can.

However, in the present embodiment, the item 136 (calorific value Q (k)) does not necessarily have to be described in the table 13, in other words, at least one of the items 134 to 136 should be described. Just do it. When item 136 (calorific value Q (k)) is not described, the control unit 11 can obtain the calorific value Q (k) by the following method.

For example, when the calorific value Q (k) is not described in the table 13 but the current I (k) (item 134) is described, the control unit 11 determines the battery current I (k) and the battery current I (k) in the order k. By calculating the following [Equation 1] using the internal resistance R (k), the calorific value Q (k) of the battery in the order k can be obtained. The internal resistance R (k) holds a value obtained by performing a charge / discharge test in advance, for example.

The internal resistance R (k) includes the battery temperature "Tcell", the continuous energization time (continuous charge time or continuous discharge time) "tkd" of the battery, and the charge state of the battery (for example, information indicating the remaining battery level). Since it changes depending on "y", the control unit 11 holds a data table or function (hereinafter referred to as a tcd data table) showing these relationships in the control unit 11, so that the control unit 11 has an internal resistance R (k). May be calculated every time. Although the tcd data table is not shown in the first embodiment, the table 22 illustrated in FIG. 3 in the second embodiment is an example of the tcd data table.

When calculating the internal resistance R (k) each time, the control unit 11 obtains the battery charge state y (k) in the order k, and further, the battery temperature Tcell detected by the temperature sensor 61 and the order of the table 13. Obtain the continuous energization time tcd that can be calculated from the information of the current I (k) before k. Then, the control unit 11 can calculate the internal resistance R (k) of the battery in the order k based on the obtained information and the tcd data table.

Further, for example, when the heat generation amount Q (k) is not described in the table 13 but the electric power P (k) (item 135) is described, the heat generation amount Q (k) of the battery in the order k is, for example, as follows. It can be calculated by the procedure of. First, the control unit 11 obtains the battery charge state y (k) in the order k and the battery open circuit voltage “OCV (k)” corresponding to the charge state y (k). Further, the control unit 11 calculates the internal resistance R (k) from the above-mentioned tcd data table based on the charging state y (k), the battery temperature Tcell, and the continuous energization time tcd. Then, the control unit 11 calculates I (k) satisfying [Equation 2] using these values, and further uses the calculated I (k) and R (k) to calculate the above [Equation 1]. By calculation, the calorific value Q (k) of the battery in the order k can be obtained.

As described above, even if the calorific value Q (k) is not listed in the table 13, the control unit 11 uses any of the above methods to perform the order k based on the input information, the table 13, and the like. The calorific value Q (k) of the battery corresponding to can be calculated. Then, the control unit 11 can similarly calculate the calorific value Q (k + 1), Q (k + 2), ..., Q (k + m) for each order (k + 1, k + 2, ..., K + m) after the order k. can. Therefore, the control unit 11 obtains the calorific value Q (k) to Q (k + m) corresponding to each of the order k corresponding to the current time to the order k + m corresponding to the predetermined time, and calculates the sum of them. , The calorific value Q_km within a predetermined time can be obtained.

Since there is a time lag between the heat generation in the battery and the temperature rise, in the second step of the control process, the control unit 11 starts from the order k corresponding to the time after a specific time from the current time. As a result, the calorific value Q_km from the order k to the order k + m may be calculated.

Next, as a third step of the control process, the control unit 11 determines the temperature difference ΔTcr between the reference temperature Tref and the battery temperature Tcell calculated in the first step, and the calorific value Q calculated in the second step. Based on the above, the amount of heat to be removed from the battery (heat removal amount S) is calculated. Strictly speaking, in the second step, the calorific value Q_km at the position or time corresponding to the order k to the order k + m is calculated. Therefore, in the third step, similarly, from the order k to the order k + m. The amount of heat removed S_km at the corresponding position or time is calculated.

Here, an example of a method for calculating the heat removal amount S_km in the third step of the control process is shown. First, it is assumed that the control unit 11 holds the heat capacity "Ccell" of the battery in advance. At this time, since it is known that the amount of heat required to set the battery temperature to Tref is “ΔTcr × Cell”, the control unit 11 calculates the amount of heat removal S_km from the following [Equation 3]. Can be done.

Further, in the third step, the control unit 11 divides the heat removal amount S_km calculated as described above by the time t_km (see [Equation 4]) corresponding to the order k and the order k + m, thereby per unit time. The amount of heat removed s_km can be calculated (see [Equation 5]).

Next, as a fourth step of the control process, the control unit 11 is based on the heat removal amount S calculated in the third step (heat removal amount S_km corresponding to the order k to k + m, or heat removal amount s_km per unit time). By referring to the table 14, the required output (F: Fan Output) in the temperature adjusting device 5 (blower fan) is calculated.

Specifically, for example, as described above, when the relationship between the output F of the temperature adjusting device 5 and the heat removal amount s_km of the battery per unit time is shown in the table 14, the control unit 11 is the third. By collating the table 14 based on the heat removal amount s_km per unit time calculated in step 1, the output F_km of the temperature adjusting device 5 in the order k to k + m can be determined.

Finally, as a fifth step of the control process, the control unit 11 controls the operation of the temperature adjusting device 5 (blower fan) based on the output F (for example, F_km) calculated in the fourth step. A specific method for controlling the operation of the temperature adjusting device 5 to the above output will not be described in detail here because various conventionally known methods can be used.

The control process by the control unit 11 for controlling the operation of the temperature adjusting device 5 described above is an operation when the heat removal amount S_km (or s_km) is larger than 0. If the heat removal amount S_km is smaller than 0, it is preferable that the control unit 11 controls to suppress the operation of the temperature adjusting device 5 such as stopping the operation of the temperature adjusting device 5 (blower fan).

(1-3) Summary As described above, in the temperature control system 1 according to the present embodiment, the battery temperature obtained from the temperature sensor 61 and the battery temperature obtained from the temperature sensor 61 by performing the control process by the control unit 11 as described above. It is necessary to input the basic information such as the vehicle position obtained from the position sensor 62, but to suppress the temperature rise (calorific value) predicted in the secondary battery and the temperature rise with a relatively small amount of calculation. The amount of heat removed can be calculated accurately, and the operation of the temperature adjusting device 5 can be appropriately controlled based on the calculated amount of heat removed.

As a result, for example, in a situation where the secondary battery is expected to become hot due to continuous energization or the like (specifically, when the heat removal amount S_km becomes larger than 0), the temperature adjusting device 5 (for example, a cooling fan) is operated. As a result, the temperature of the secondary battery can be maintained near the reference temperature.

Further, for example, when the secondary battery is charged and discharged at a low temperature, the battery temperature Tcell becomes lower than the reference temperature Tref (Tcell <Tref), and the heat removal amount S_km is considered to be smaller than 0. In such a case, the control unit 11 controls to suppress the operation of the temperature adjusting device 5, so that it is possible to suppress the continuation of the low temperature state of the secondary battery. Thus, according to the temperature control system 1 according to the present embodiment, deterioration due to charging / discharging of the secondary battery at a low temperature can be suppressed.

The temperature control system 1 according to the present embodiment is particularly suitable for controlling the temperature of a secondary battery in which a charge / discharge pattern is substantially determined, such as a secondary battery for a railroad vehicle. It is a thing.

From the above, the temperature control system 1 according to the present embodiment realizes temperature control of the secondary battery based on highly accurate heat generation prediction of the secondary battery while suppressing the calculation load due to complicated calculation. By appropriately controlling the temperature of the secondary battery, the secondary battery can be used stably for a long period of time.

(2) Second Embodiment FIG. 3 is a block diagram showing a configuration example of the temperature control system 2 according to the second embodiment of the present invention and its control flow. As shown in FIG. 3, the temperature control system 2 according to the second embodiment includes a control unit (Controller) 21, a reference temperature data (Tref) 12, a table (Table_A) 13, and a table (Table_B) 14. A table (Table_C) 22 and a resistance determination unit (Resistance Analyzer) 23 are provided. Of these, the reference temperature data 12, the table 13, and the table 14 have the same configurations as those described in the first embodiment, and the description thereof will be omitted.

Compared with the temperature control system 1 (FIG. 1) according to the first embodiment, the temperature control system 2 according to the second embodiment is different in that it further includes a table 22 and a resistance determination unit 23.

Similar to the tcd data table described in the first embodiment, the table 22 shows the battery temperature Tcell, the continuous energization time (continuous charging time or continuous discharging time) tcd of the battery, the charging state y of the battery, and the battery. It is a data table which shows the relationship with the internal resistance R (internal resistance Rini in the initial state of a battery). Therefore, by collating the table 22 with the battery temperature Tcell, the continuous energization time tcd, and the charging state y as inputs, the control unit 21 can obtain the internal resistance Rini in the initial state of the battery. In the second embodiment, the control unit 21 may hold the internal resistance Rini in the initial state of the battery as a reference value in advance, instead of calculating using the table 22.

The resistance determination unit 23 has a function of determining the actual internal resistance Rnow of the battery based on the current I and the voltage V of the battery. As will be described later, since the current I and voltage V of the battery are the actually detected values input from the current sensor 63 and the voltage sensor 64, the resistance determination unit 23 actually uses the input values of the battery. The internal resistance Rnow is determined, and the determination result is output to the control unit 21.

In addition to the temperature sensor (Sensor_A) 61 and the position sensor (Sensor_B) 62, the current sensor (Sensor_C) 63, the voltage sensor (Sensor_D) 64, and the charging state determination unit (SOC Analyzer) are outside the temperature control system 2. ) 65 is provided.

The current sensor 63 is a sensor that detects the current I of the battery, and the detected current I is input to the resistance determination unit 23. The voltage sensor 64 is a sensor that detects the voltage V of the battery, and the detected voltage V is input to the resistance determination unit 23. The charge state determination unit 65 has a function of determining the charge state y of the battery, and the determined charge state y is input to the control unit 21.

In the temperature control system 2 configured as described above, the control unit 21 performs control processes (first to first) for controlling the operation of the temperature adjusting device 5 as described in the first embodiment. By performing step 5), the temperature control of the battery is realized. However, in the second embodiment, among such control processes, the calorific value Q calculated in the second step (specifically, the calorific value Q_km at the position or time corresponding to the order k to k + m). The control unit 21 compares the actual internal resistance Rnow of the battery with the internal resistance Rini in the initial state of the battery, and corrects the calorific value Q of the battery. As described above, the internal resistance Rini in the initial state of the battery may be an internal resistance value previously held in the control unit 21 as a reference value in a predetermined charging state, battery temperature, and continuous energization time, or the table 22. It may be the internal resistance value obtained by using.

Specifically, the control unit 21 determines the correction coefficient r with respect to the calorific value Q of the battery based on the internal resistance Rnow and the internal resistance Rini. The correction coefficient r can be calculated from, for example, the ratio of "Rnow / Rini". Then, the control unit 21 applies the calorific value Q obtained by using the table 13 (or, as described in the first embodiment, the calorific value Q calculated based on the current I and the electric power P). On the other hand, the correction coefficient r is multiplied, and the corrected "r × Q" is taken as the calorific value. After that, as in the first embodiment, the battery temperature is appropriately managed by executing the third step to the fifth step of the control process to control the operation of the temperature adjusting device 5. be able to.

According to the temperature control system 2 according to the second embodiment, the same effect as that of the temperature control system 1 according to the first embodiment can be obtained. Further, the calorific value used in the middle of the calculation for the control process can be calculated in consideration of the actual internal resistance Rnow, so that the calorific value based on the more correct internal resistance can be calculated. It is possible to control the temperature of the secondary battery with higher accuracy than the form.

(3) Third Embodiment FIG. 4 is a block diagram showing a configuration example of the temperature control system 3 according to the third embodiment of the present invention and its control flow. As shown in FIG. 4, the temperature control system 3 according to the third embodiment includes a control unit (Controller) 31, a reference temperature data (Tref) 12, a table (Table_A) 13, and a table (Table_B) 14. And a table (Table_D) 32. Of these, the reference temperature data 12, the table 13, and the table 14 have the same configurations as those described in the first embodiment, and the description thereof will be omitted. Details of the table 32 will be described later.

Further, the temperature control system 3 has a temperature sensor 61, a position sensor 62, a current sensor 63, a voltage sensor 64, and a charging state determination unit 65, similarly to the temperature control system 2 (FIG. 3) according to the second embodiment. Is provided externally, and from each of these configurations, the battery temperature Tcell, the vehicle position x, the current I, the voltage V, and the charging state y are input to the control unit 31 (in the third embodiment, the temperature). Since the control system 2 does not have a configuration corresponding to the resistance determination unit 23, the current I and the voltage V are also directly input to the control unit 31).

In the temperature control system 3 configured as described above, the control unit 31 controls the operation of the temperature adjusting device 5 (first) as described in the first or second embodiment. By performing (5th step), the temperature control of the battery is realized. However, the temperature control system 3 according to the third embodiment is different in that the table 13 collated in the second step is appropriately corrected based on the actual vehicle traveling situation. It has characteristics different from those of the embodiment. This feature will be described in detail below.

First, in the temperature control system 3, the table 13 is a data table in which information in a standard situation of vehicle running is described, and the specific description contents are the position x of the railroad vehicle and the specific description contents as illustrated in FIG. The correspondence between the time t and the current I, the electric power P, and the calorific value Q in the battery is shown.

However, in reality, since there are deterioration of battery characteristics, changes in temperature, etc., the current "I'", the electric power "P'", and the calorific value "Q'" at the time of actual vehicle running are shown in Table 13. It may be different from the current I, the power P, and the calorific value Q in the described “standard situation”.

That is, in the above case, as in the first embodiment, the calorific value Q is calculated based on the table 13, the calorific value S is calculated based on the calorific value Q, and the operation of the temperature adjusting device 5 is performed. Even if it is controlled, the battery temperature after the operation control may greatly deviate from the target reference temperature Tref.

Therefore, in the present embodiment, the table 13 is corrected by using the current I', the electric power P', the calorific value Q', and the battery temperature Tcell when the vehicle is actually running, in order to further improve the accuracy of the temperature adjustment. It is a thing. In the present embodiment, a table 32 is prepared in order to realize such a correction.

The table 32 is a data table that collects and records the history of the current I', the electric power P', and the battery temperature Tcell during the actual running of the vehicle in which the battery is charged and discharged. At the vehicle position x (k) and time t (k) shown in the table 13, the control unit 31 determines the current I'actually flowing through the battery while the vehicle is running, the required power P'to the battery, and the battery temperature. Record Tcell (k) in table 32.

FIG. 5 is a diagram showing an example of the table 32. The table 32 illustrated in FIG. 5 is composed of items 321 to 326.

In item 321, the order "k" of the data arrangement is described (k = 0,1, ..., N), and items 322 to 327 are described in a form corresponding to each order k. Specifically, the vehicle position "x (k)" is described in the item 322, and the time "t (k)" is described in the item 323. These items 321 to 323 correspond to items 131 to 133 in the table 13 illustrated in FIG. In addition, items 324 to 327 are estimated in terms of the current I'(k) (item 324) actually flowing through the battery while the vehicle is running, the required power P'(k) (item 325) for the battery, and the battery. The actual calorific value Q'(k) (item 326) and the battery temperature Tcell (k) (item 327) are described.

By recording the data in the format shown in FIG. 5, the table 32 records the history of the actual vehicle running when the battery is charged and discharged for each time of the vehicle running (from the start of running to the end of running). It can be held in a form corresponding to each order k (for example, by making the vehicle run once).

Next, an example of a method in which the control unit 31 corrects the table 13 using the table 32 will be described.

First, the control unit 31 searches the table 32 for data corresponding to the vehicle position x (k) or the time t (k) in the order k of the table 13. Here, it is assumed that the corresponding data is found in the order k'of the table 32.

Next, the control unit 31 calculates the current I (k) in the order k of the table 13 based on the current I (k) in the order k of the table 13 and the current I'(k') in the order k'of the table 32. Correct to "I" (k) ". A specific example of the correction formula is shown in [Equation 6] below.

Although the constant C can be arbitrarily selected in [Equation 6], it is preferably 1 or less in order to prevent the influence of the current I'(k') on the correction from becoming excessive.

Further, the control unit 31 can correct the table 13 by using the table 32 for the electric power P (k) as well as the current I (k). That is, based on the power P (k) in the order k of the table 13 and the power P'(k') in the order k'of the table 32, the power P (k) in the order k of the table 13 is set to "P" ( k) ”. A specific example of the correction formula is shown in [Equation 7] below.

Further, the control unit 31 can correct the calorific value Q based on the battery temperature T cell. For example, when the temperature control based on the table 13 is performed, the actual battery temperature Tcell is different from the temperature even though the battery temperature in the order k + m is predicted to be the reference temperature Tref. , The temperature difference ΔTcr (when Tcell> Tref, ΔTcr = Tcell-Tref) is considered to be based on the difference in calorific value Q.

At this time, assuming that the heat capacity of the battery is "Ccell", it can be said that the calorific value indicated by "ΔTcr × Ccell" was larger than the predicted calorific value Q. Therefore, the control unit 31 corrects the calorific value Q_km in the order k to k + m calculated based on the table 13 to "Q'_km" based on the temperature difference ΔTcr and the heat capacity “Ccell” of the battery. A specific example of the correction formula is shown in [Equation 8] below.

The corrected calorific value Q''(k) in each order from k to k + m can be calculated by, for example, the following [Equation 9].

As described above, in the third embodiment, the control unit 31 of the temperature control system 3 has the information (current I (k), The electric power P (k) and the calorific value Q (k)) can be corrected. Then, the control unit 31 performs control processing after the third step based on the corrected information (current I ″ (k), electric power P ″ (k), calorific value Q ″ (k)). By executing the above, it is possible to realize highly accurate temperature adjustment in consideration of the battery temperature during actual vehicle running.

In the third embodiment, in the correction of the table 13, the table 32, which is the history of the measured data, is not used as it is. This is because the table 32 is basically past data, and the running conditions in the past each time vary depending on the temperature, speed, etc. Therefore, if such a table 32 is used as it is for the temperature control this time, it will run instead. This is because there is a concern that the control of the above will not be performed correctly. Therefore, based on the values in Table 13, the values in Table 32, which are the actual results, are corrected by applying appropriate weights so that the corrected values are gradually adjusted to the actual conditions. ..

In the third embodiment, by carefully repeating the correction of the table 13 as described above, it can be expected that the value of the corrected table 13 approaches the actual value (or its average value). Therefore, the accuracy of battery temperature control by the control unit 31 is improved, and the effect of preventing deterioration of the battery (prolonging the life of the battery) can be expected.

(4) Fourth Embodiment FIG. 6 is a block diagram showing a configuration example of the temperature control system 4 according to the fourth embodiment of the present invention and its control flow.

As shown in FIG. 6, the configuration of the temperature control system 4 according to the fourth embodiment has many points in common with the configuration of the temperature control system 1 according to the first embodiment illustrated in FIG. On the other hand, in the first embodiment, the reference temperature Tref, which is the target temperature for temperature control of the battery during charging / discharging, is held by the reference temperature data 12 as a predetermined fixed value. The fourth embodiment is different in that the reference temperature Tref is not set as a fixed value, and the reference temperature Calculator 42 provided instead of the reference temperature data 12 can calculate and set the reference temperature Tref. ing.

Here, it is said that the deterioration of the secondary battery includes "leaving deterioration" that progresses only by storing the battery without charging and discharging, and "charging and discharging deterioration" that progresses by charging and discharging. Of these, it is known that "leaving deterioration" progresses faster at higher temperatures, whereas "charge / discharge deterioration" may progress faster at lower temperatures. Since the actual battery deterioration is the sum of the neglected deterioration and the charge / discharge deterioration, there is an optimum temperature for minimizing the battery deterioration.

To explain in more detail the optimum temperature that minimizes battery deterioration, when there is no charge / discharge load on the battery or it is very small, "leaving deterioration" is the main cause of battery deterioration, so the lower the temperature, the more the battery deteriorates. Is smaller (the optimum temperature that minimizes battery deterioration is lower). On the other hand, when the charge / discharge load on the battery is large, the contribution rate of "charge / discharge deterioration" as a factor of battery deterioration becomes large, so that the optimum temperature for minimizing the battery deterioration becomes high.

Therefore, when the charge / discharge load on the battery changes, it is assumed that the optimum temperature (reference temperature Tref) that should be set to suppress battery deterioration is not a fixed value, and in view of this background, In the present embodiment, the reference temperature calculation unit 42 (or control unit 41) calculates the charge / discharge load on the battery, and dynamically calculates the reference temperature Tref based on the charge / discharge load.

The calculation of the reference temperature Tref by the reference temperature calculation unit 42 (or the control unit 41) will be described in detail. First, the reference temperature calculation unit 42 is, for example, a computer provided inside the temperature control system 4. The reference temperature calculation unit 42 may be controlled by the control unit 41 or may be substituted by the control unit 41.

The reference temperature calculation unit 42 (or control unit 41) uses the battery temperature Tcell input from the temperature sensor 61, the vehicle position x input from the position sensor 62, and the data (see FIG. 2) shown in the table 13. Based on this, the charge / discharge load from a certain order k to the order k + m is calculated. Here, the calculation standard (judgment standard) of the charge / discharge load may be arbitrarily determined, but for example, a method of using the average of the absolute values of the charge / discharge current, a method of using the effective current of the charge / discharge current, and the like are known. There is.

Further, it is assumed that the reference temperature calculation unit 42 (or control unit 41) holds a data table or a function (not shown) showing the relationship between the charge / discharge load and the reference temperature, and based on this data table or the like, The reference temperature Tref is calculated and set from the calculated charge / discharge load. The relationship between the charge / discharge load and the reference temperature differs depending on the specifications and characteristics of the battery, but as an overall tendency, it is preferable to have a relationship in which the higher the charge / discharge load, the higher the reference temperature. The reason is that, as described above, "charge / discharge deterioration" progresses faster at lower temperatures.

However, it is preferable to set a predetermined upper limit in the range of the reference temperature Tref calculated from the charge / discharge load by the reference temperature calculation unit 42 (or the control unit 41). The reason is that when the battery temperature is raised, the internal resistance R of the battery is lowered, so that the effect of suppressing charge / discharge deterioration can be expected. However, when the battery temperature is excessively high, the progress of "leaving deterioration" is accelerated. Therefore, there is a risk that the (composite) battery deterioration will progress as a whole. Further, if the battery temperature is excessively high, there is a concern about denaturation of the battery material.

As described above, the reference temperature calculation unit 42 (or the control unit 41) can dynamically calculate the reference temperature Tref that minimizes the deterioration of the battery based on the charge / discharge load on the battery. Then, using the reference temperature Tref calculated in this way, the control unit 41 controls the operation of the temperature adjusting device 5 as in the first embodiment (first to fifth). By executing step), it is possible to realize highly accurate battery temperature control that minimizes battery deterioration according to the actual situation.

(5) Fifth Embodiment In the fifth embodiment, it is assumed that the temperature adjusting device 5 has both a cooling function (for example, a blower fan) and a heating function (for example, a heater) for the battery temperature, and the temperature control system. The configuration may be any of the first to fourth embodiments.

When operating a vehicle in winter or in cold regions, the battery temperature may become low, especially when the vehicle is started. In such a case, the internal resistance R of the battery becomes large and the progress of deterioration becomes fast (see also the feature of "charge / discharge deterioration" described in the fourth embodiment). Therefore, in order to suppress the deterioration of the battery and to use it stably for a long period of time, it is effective to control the battery temperature so as to raise it.

Further, when a plurality of battery cells are connected and used, the temperature and voltage between the cells tend to be non-uniform. In such a case, it is known that it is preferable to reduce the internal resistance R of the battery by heating rather than controlling the operation of the temperature adjusting device 5 so as to cool the battery.

Therefore, in the temperature control system according to the fifth embodiment, in a situation where the battery temperature should be lowered, the temperature adjusting device 5 cools the battery (for example, by the same control process as in the first to fourth embodiments). While controlling the operation of the blower fan), in the situation where the battery temperature should be raised in order to use the battery stably for a long period of time as described above, the temperature adjusting device 5 controls the heating operation of the battery (for example, the operation of the heater). ) Is controllable.

Regarding the specific processing of the control unit when controlling the heating operation of the battery in the fifth embodiment, for example, the control processing described in the first embodiment (first to fifth steps). Can be used.

To briefly explain the outline, first, the control unit executes the first to third steps, and is based on the temperature difference ΔTcr between the reference temperature Tref and the battery temperature Tcell and the calculated calorific value Q_km. The amount of heat removed from the battery S_km (or the amount of heat removed per unit time s_km) is calculated.

When the heat removal amount S_km (or s_km) becomes smaller than 0 as a result of the third step, the heat amount corresponding to the absolute value of the negative heat removal amount S_km (or s_km) in the fourth step. The output of the temperature control device 5 (heater) required to transmit the heat to the battery is calculated. In order to calculate the output of the heater in the fourth step, for example, the table 14 shows the correspondence between the output of the temperature adjusting device 5 when the heater is operating and the heat removal amount s_km of the battery per unit time. do.

Then, in the fifth step, the control unit controls the operation of the temperature adjusting device 5 (heater) based on the output calculated in the fourth step, so that the low temperature battery temperature Tcell reaches the reference temperature Tref. The temperature of the battery can be adjusted as described above.

As described above, according to the temperature control system according to the fifth embodiment, in a situation where it is preferable to raise the battery temperature Tcell, the cooling operation by the temperature adjusting device 5 (for example, a blower fan) is suppressed and the battery is naturally generated. By controlling the active heating operation by a heater or the like instead of waiting for the temperature Tcell to rise, the battery temperature Tcell can be brought closer to the reference temperature Tref earlier, so that the calculation load due to complicated calculation can be increased. While suppressing it, it is possible to realize temperature control of the secondary battery based on highly accurate prediction of heat generation of the secondary battery. In particular, it is effective against deterioration caused by charging / discharging the secondary battery at a low temperature (charging / discharging deterioration at a low temperature).

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, each of the above-described embodiments has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those having all the described configurations. Further, it is possible to replace a part of the configuration in one embodiment with the configuration in another embodiment, and it is also possible to add the configuration in another embodiment to the configuration in one embodiment. .. Further, it is possible to add / delete / replace a part of the configuration in each embodiment with another configuration.

Further, the configurations, functions, processing units, processing means and the like shown in each embodiment may be realized by hardware by designing a part or all of them by, for example, an integrated circuit. Further, each of the above configurations, functions, and the like may be realized by software by the processor interpreting and executing a program that realizes each function. Information such as programs, tables, and files that realize each function can be placed in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

In addition, the control lines and information lines are shown as necessary for explanation, and not all control lines and information lines are necessarily shown in the product. In practice, almost all configurations may be considered interconnected.

1-4 Temperature Control System
5 Temperature controller (Fan)
11,21,31,41 Controller
12 Reference temperature data (Tref)
13 Table (Table_A)
14 Table (Table_B)
22 Table (Table_C)
23 Resistance Analyzer
32 table (Table_D)
42 Reference temperature calculator (Calculator)
61 Temperature sensor (Sensor_A)
62 Position sensor (Sensor_B)
63 Current sensor (Sensor_C)
64 Voltage sensor (Sensor_D)
65 Charge status determination unit (SOC Analyzer)

Claims (15)

A secondary battery temperature control system that adjusts the temperature of a secondary battery mounted on a vehicle to a reference temperature by controlling the operation of a predetermined temperature control device.
A control unit that controls the operation of the temperature regulator and
A first data table showing a correspondence relationship between the position information or time information regarding the vehicle and at least one of the charge / discharge current, charge / discharge power, or heat generation amount of the secondary battery.
A second data table showing the correspondence between the amount of heat removed, which means the amount of heat removed from the secondary battery, and the output of the temperature regulator, and
With
The control unit
Using the position information or the time information obtained for the vehicle as an input, the calorific value of the secondary battery within a predetermined time is calculated based on the first data table.
Based on the calculated calorific value, the detection temperature of the secondary battery, and the temperature difference of the reference temperature, the heat removal amount within the predetermined time is calculated.
Using the calculated heat removal amount as an input, the output of the temperature adjusting device is calculated based on the second data table.
A temperature control system for a secondary battery, characterized in that the temperature adjusting device is operated based on the calculated output. The control unit
Using the internal resistance of the secondary battery and the charge / discharge current of the secondary battery calculated based on the first data table by inputting the position information or the time information obtained for the vehicle. The temperature control system for a secondary battery according to claim 1, wherein the calorific value of the secondary battery is calculated within the predetermined time. The control unit
The calculation is performed based on the first data table by inputting the charge state, open circuit voltage, detection temperature, continuous energization time of the secondary battery, and the position information or the time information obtained for the vehicle. The temperature control system for a secondary battery according to claim 1, wherein the charge / discharge power of the secondary battery is used to calculate the calorific value of the secondary battery within the predetermined time. A third data table showing the correspondence between the charge state, continuous energization time, and detection temperature of the secondary battery and the internal resistance in the initial state of the secondary battery.
A resistance determination unit that determines the actual internal resistance of the secondary battery based on the detection current and detection voltage of the secondary battery.
With more
The control unit
Using the charging state, continuous energization time, and detection temperature of the secondary battery as inputs, the internal resistance of the secondary battery in the initial state is calculated based on the third data table.
Based on the calculated internal resistance and the actual internal resistance of the secondary battery determined by the resistance determination unit, a correction coefficient for the calorific value of the secondary battery is determined.
The secondary battery according to claim 1, wherein the determined correction coefficient is used to correct the calorific value of the secondary battery within the predetermined time calculated based on the first data table. Temperature control system. As the history information associated with the actual running of the vehicle, the correspondence relationship between the position information or time information related to the vehicle and the actual charge / discharge current, charge / discharge power, or heat generation amount of the secondary battery is described. With more data tables
The temperature control system for a secondary battery according to claim 1, wherein the control unit corrects the first data table based on the history information described in the fourth data table. The temperature control system for a secondary battery according to claim 1, further comprising a reference temperature calculation unit for calculating the reference temperature based on the detection temperature of the secondary battery and the position information of the vehicle. The reference temperature calculation unit
Based on the detection temperature of the secondary battery, the position information of the vehicle, and the information shown in the first data table, the charge / discharge load on the secondary battery is calculated.
The temperature control system for a secondary battery according to claim 6, wherein the reference temperature is calculated based on the calculated charge / discharge load so as to suppress battery deterioration of the secondary battery. When the temperature controller has a cooling function and a heating function for the secondary battery,
The control unit
When the heat removal amount within the calculated predetermined time is larger than 0,
The output of the cooling function of the temperature regulator is calculated based on the heat removal amount and the second data table, and the cooling function of the temperature regulator is operated based on the calculated output.
When the heat removal amount within the calculated predetermined time is smaller than 0,
It is characterized in that the output by the heating function of the temperature adjusting device is calculated based on the heat removal amount and the second data table, and the heating function of the temperature adjusting device is operated based on the calculated output. The temperature control system for a secondary battery according to claim 1. It is a method of controlling the temperature of a secondary battery by a temperature control system of the secondary battery that adjusts the temperature of the secondary battery mounted on the vehicle to a reference temperature by controlling the operation of a predetermined temperature adjusting device.
The temperature control system for the secondary battery is
A control unit that controls the operation of the temperature regulator and
A first data table showing a correspondence relationship between the position information or time information regarding the vehicle and at least one of the charge / discharge current, charge / discharge power, or heat generation amount of the secondary battery.
A second data table showing the correspondence between the amount of heat removed, which means the amount of heat removed from the secondary battery, and the output of the temperature regulator, and
Have,
A first step of calculating the calorific value of the secondary battery within a predetermined time based on the first data table by inputting the position information or the time information obtained for the vehicle.
A second step of calculating the heat removal amount within the predetermined time based on the calorific value calculated in the first step and the temperature difference between the detection temperature of the secondary battery and the reference temperature.
With the heat removal amount calculated in the second step as an input, the third step of calculating the output of the temperature adjusting device based on the second data table, and
The fourth step of operating the temperature control device based on the output calculated in the third step, and
A method for controlling the temperature of a secondary battery, which comprises. In the first step,
Using the internal resistance of the secondary battery and the charge / discharge current of the secondary battery calculated based on the first data table by inputting the position information or the time information obtained for the vehicle. The method for controlling the temperature of a secondary battery according to claim 9, wherein the calorific value of the secondary battery is calculated within the predetermined time. In the first step,
The calculation is performed based on the first data table by inputting the charge state, open circuit voltage, detection temperature, continuous energization time of the secondary battery, and the position information or the time information obtained for the vehicle. The temperature control method for a secondary battery according to claim 9, wherein the charge / discharge power of the secondary battery is used to calculate the calorific value of the secondary battery within the predetermined time. The temperature control system for the secondary battery is
A third data table showing the correspondence between the charging state, continuous energization time, and detection temperature of the secondary battery and the internal resistance in the initial state of the secondary battery.
A resistance determination unit that determines the actual internal resistance of the secondary battery based on the detection current and detection voltage of the secondary battery.
Have more
Using the charging state, continuous energization time, and detection temperature of the secondary battery as inputs, the internal resistance of the secondary battery in the initial state is calculated based on the third data table, and the calculated internal resistance and the calculated internal resistance are used. Based on the actual internal resistance of the secondary battery determined by the resistance determination unit, a correction coefficient for the calorific value of the secondary battery is determined, and the determined correction coefficient is used to determine the first correction coefficient. The fifth step of correcting the calorific value of the secondary battery within the predetermined time calculated in the step of is further provided.
The fifth step is performed between the first step and the second step.
The temperature control method for a secondary battery according to claim 9, wherein the second step is executed using the calorific value corrected in the fifth step. The temperature control system for the secondary battery is
As the history information associated with the actual running of the vehicle, the correspondence relationship between the position information or time information related to the vehicle and the actual charge / discharge current, charge / discharge power, or heat generation amount of the secondary battery is described. It also has a data table of
A sixth step of correcting the first data table based on the historical information described in the fourth data table is further provided.
The method for controlling the temperature of a secondary battery according to claim 9, wherein the first step is executed using the first data table corrected by the sixth step. The temperature control system for the secondary battery is
It further has a reference temperature calculation unit that calculates the reference temperature based on the detection temperature of the secondary battery and the position information of the vehicle.
The reference temperature calculation unit calculates the charge / discharge load on the secondary battery based on the detected temperature of the secondary battery, the position information of the vehicle, and the information shown in the first data table. A seventh step of calculating the reference temperature based on the calculated charge / discharge load so as to suppress battery deterioration of the secondary battery is further provided.
The temperature control method for a secondary battery according to claim 9, wherein the second step is executed using the reference temperature calculated by the seventh step. When the temperature controller has a cooling function and a heating function for the secondary battery,
If the amount of heat removed calculated in the second step is larger than 0,
In the third step, the output by the cooling function of the temperature regulator is calculated based on the heat removal amount and the second data table, and in the fourth step, it is calculated in the third step. While operating the cooling function of the temperature regulator based on the output
If the amount of heat removed calculated in the second step is less than 0,
In the third step, the output by the heating function of the temperature adjusting device is calculated based on the heat removal amount and the second data table, and in the fourth step, it is calculated in the third step. The temperature control method for a secondary battery according to claim 9, wherein the heating function of the temperature adjusting device is operated based on the output.

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