JP4645566B2 - Electric vehicle capacity adjustment device - Google Patents

Description

  The present invention relates to a capacity adjustment device for an assembled battery mounted on an electric vehicle.

  Conventionally, a capacity adjustment method for an assembled battery in which a plurality of cells are connected in series is known (see, for example, Patent Document 1). In the conventional capacity adjustment method, a capacity adjustment target and a capacity adjustment time are determined for each cell in accordance with the cell voltage distribution state at the time of no load, and discharging is performed at a specified current value.

JP 2003-284253 A

  However, since the conventional technique discharges at a specified current value, when it is desired to quickly adjust the capacity, the system may be turned off before the capacity adjustment is completed because the capacity adjustment time is long. is there. Therefore, there has been a problem that capacity adjustment cannot be performed sufficiently. The case where capacity adjustment is desired to be performed immediately is, for example, a case where the variation in cell capacity is very large or a case where the vehicle usage time is extremely short.

The present invention is applied to a capacity adjusting device for an electric vehicle having a capacity adjusting resistor having a fixed resistance value for each cell constituting the assembled battery, and controls the charging / discharging of the assembled battery, and the SOC (State Of Charge) of the assembled battery. Charging / discharging control means for controlling the battery pack to a predetermined range including the battery pack target SOC, and setting means for setting the battery pack target SOC during capacity adjustment higher than the battery pack target SOC during non-capacity adjustment , setting means calculates a standard deviation of the difference and the cell voltage between the average cell voltage and the minimum cell voltage of the battery pack, the battery pack target SOC to the large set in the higher capacity adjustment the difference is large, the standard deviation The smaller the is, the larger the battery pack target SOC during capacity adjustment is set .

  According to the present invention, since the assembled battery target SOC during capacity adjustment is set higher than the assembled battery target SOC during non-capacity adjustment, the SOC of the assembled battery during capacity adjustment is less than during non-capacity adjustment. Will also be higher. As a result, the cell voltage increases, the current flowing through the capacitance adjustment resistor increases, and the capacitance adjustment capability improves.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.
-First embodiment-
FIG. 1 is a diagram showing a first embodiment of a capacity adjustment apparatus according to the present invention, and shows a hardware configuration of a control system when applied to a capacity adjustment apparatus of an HEV (hybrid vehicle). In FIG. 1, a thick solid line indicates a high-power line, a thin solid line indicates a low-power line, and a dotted line indicates a signal line. The capacity adjusting device according to the present invention can be applied not only to HEV (hybrid vehicle) but also to FCV (fuel cell vehicle), EV, etc., and in that case, the configuration related to the battery is not different from that shown in FIG. .

The control system shown in FIG. 1 includes a vehicle system 3 provided with an assembled battery 2 and a battery control unit 1. The battery control unit 1 includes a cell voltage detection unit 101, a capacity adjustment unit 102, a CPU 103, a memory 104, and the like, and performs charge / discharge control and capacity adjustment control of the assembled battery 2 provided in the vehicle system 3. The assembled battery 2 has a plurality of cells connected in series, and the voltage of each cell is detected by the cell voltage detector 101. The voltage information of each cell detected by the cell voltage detection unit 101 is transmitted to the CPU 103.

  The CPU 103 issues an appropriate capacity adjustment instruction to the capacity adjustment unit 102 based on the voltage status (voltage distribution status) of each cell after no load (when the vehicle system is activated) and after charging the specified capacity. When the capacity adjustment is interrupted due to the vehicle system being turned off, the CPU 103 stores the remaining adjustment conditions in the memory 104 for each cell. The capacity adjustment unit 102 corrects capacity variation between cells by performing capacity adjustment in units of cells. Details of the capacity adjustment unit 102 will be described later. The memory 104 stores information necessary for charge / discharge control and capacity adjustment control, information from the CPU 103, and the like.

  The assembled battery 2 is connected to the inverter 301 and the auxiliary machine system 302 via the main relays 303a and 303b, and supplies DC power to the inverter 301 and the auxiliary machine system 302. By turning on and off the main relays 303a and 303b based on a command from the CPU 103, the power on / off of the high voltage circuit is controlled. The inverter 301 converts the DC power of the assembled battery 2 into AC power and applies it to the driving motor M, and drives the motor M to run the vehicle. The drive motor M functions as a generator during regenerative control, supplies regenerative power to the assembled battery 2 via the inverter 301, and charges the assembled battery 2. The assembled battery 2 is cooled by a cooling fan 310.

  The vehicle system CPU 304 controls the vehicle system 3, and the inverter 301 and the auxiliary system 302 are controlled by the vehicle system CPU 304. The auxiliary machine system 302 includes an air conditioning system installed in the vehicle and is driven by the electric power of the assembled battery 2. The current sensor 201 monitors the current flowing through the high power circuit of the vehicle system 3 and transmits the information to the CPU 103 of the battery control unit 1.

  The voltage sensor 202 monitors the potential difference between both ends of the assembled battery 2 and transmits the information to the CPU 103. The temperature sensor 203 monitors the temperature of the assembled battery 2 and transmits the temperature information to the CPU 103. The SOC (State Of Charge) of the assembled battery 2 is obtained by referring to a correlation table between the total voltage of the assembled battery 2 and the SOC. In this case, the detected value of the voltage sensor 203 may be used as the total voltage. You may use the sum total of the cell voltage detected by the cell voltage detection part 101. FIG. The correlation table is stored in the memory 104.

  The auxiliary battery 401 is a power source for the CPU 103 and the vehicle system CPU 304, and a switch 403 for turning on / off the power source is turned on / off by an ignition signal 402. The ignition signal 402 is input in conjunction with the on / off of the ignition switch of the vehicle. The history of the ignition signal 402, that is, the on / off history of the switch 403 is stored in the memory 104, and is used to calculate the usage time described later. When an abnormality occurs in the vehicle system 3, the vehicle system CPU 304 turns on the warning lamp 305 to notify the driver of the occurrence of the abnormality.

  FIG. 2 is a diagram showing details of the capacity adjustment unit 102, and shows three cells among a plurality of cells provided in the assembled battery 2. The capacity adjustment unit 102 performs capacity adjustment independently for each of the cells C1 to C3, and the capacity adjustment circuits 12, 22, and 32 including the capacity adjustment resistor R10 and the switching element 11 include the cells C1 to C1. It is provided in parallel with C3. An FET, a transistor, or the like is used as the switching element 11, and the switching element 11 is turned on (energized) when adjusting the capacitance.

  The switching elements 11 provided in the capacitance adjustment circuits 12, 22, and 32 are independently turned on / off by signals from the CPU 103. The capacity adjustment circuits 12, 22, and 32 turn on the switching element 11 to cause a current to flow through the capacity adjustment resistor R10, thereby discharging the cells C1 to C3, thereby adjusting the capacity of the cells C1 to C3.

  By the way, since the resistance value of the capacity adjustment resistor R10 is a fixed value, the capacity adjustment capacity cannot be improved according to the situation, for example, when it is desired to adjust the capacity quickly. In the present embodiment, the cell voltage is increased by increasing the assembled battery target SOC during capacity adjustment, and the capacity adjustment capability is improved by increasing the current value of the capacity adjustment resistor R10.

  FIG. 3 is a flowchart showing an example of capacity adjustment control in the present embodiment. The capacity adjustment is executed when the variation of the cell voltage becomes a predetermined value or more in a state where the vehicle system is activated. In addition, the cell voltage variation is also examined when the ignition is turned on, and if the variation is equal to or greater than a predetermined value, the capacity is adjusted. FIG. 3 shows the capacity adjustment when the ignition is turned on. After that, every time it is determined that the capacity adjustment is necessary, the same processing as in FIG. 3 is executed.

  In step S11, after the ignition signal is detected and before the main relays 303a and 303b are turned on, the cell voltage detector 101 detects the open voltage of each cell. In step S12, the CPU 103 calculates an average cell voltage and a cell voltage standard deviation based on the cell voltage detected in step S11, and calculates a difference between the average cell voltage and the lowest cell voltage.

  In step S <b> 13, the CPU 103 obtains the system activation time and the non-energization time when the switch 403 is off based on the on / off history of the switch 403 stored in the memory 104, and calculates the system usage time ratio. . The system usage time ratio is a ratio between the system startup time and the total usage time (= system startup time + non-energization time), and is an index corresponding to the usage time of the assembled battery. In step S14, a capacity deterioration coefficient (= current capacity / new capacity) indicating the capacity deterioration state of the assembled battery 2 is checked. For example, the capacity deterioration coefficient is obtained from the difference between the voltage value estimated from the change in capacity obtained from the charge / discharge integration (the voltage value calculated assuming that the battery is new) and the actually detected voltage value. be able to.

  In step S15, the capacity adjustment capability improvement request level is calculated based on the data collected in steps S12 to S14. Here, the capacity adjustment capability improvement request levels k1 to k3 are calculated for each data, and the final capacity adjustment capability improvement request level k is calculated based on the calculated request levels k1 to k3. FIG. 4 is a diagram illustrating an example of the capacity adjustment capability improvement request level k1 based on the data obtained in step S12. The horizontal axis represents the difference between the average cell voltage and the minimum cell voltage, and the vertical axis represents the cell voltage standard deviation. The map of the required degree k1 at the time is shown. That is, the required degree k1 (≧ 1) is set by a combination of the difference and the cell voltage standard deviation.

  Each of the lines L1 to L5 indicates a line having the same required degree. For example, all points (difference, cell voltage standard deviation) on the line L1 have the same required degree k1 (L1). Since the variation in the self-discharge amount of each cell is large, a state occurs in which the charge capacity of some cells is considerably lower than other cells, but the map shown in FIG. 4 quickly eliminates such a state. This is a map with particular emphasis. The required levels k1 (L1) to k1 (L5) of the lines L1 to L5 are set such that k1 (L1) <k1 (L2) <k1 (L3) <k1 (L4) <k1 (L5).

  FIG. 7 qualitatively shows the states of the points P1 and P2 in FIG. FIG. 7A shows the cell voltage distribution at the point P1 on the line L2 with the required level k1 (L2). Many cells are distributed near the average cell voltage, and the cell with the lowest cell voltage is below that. There is one. Black circles represent the number of cells. On the other hand, FIG. 7B shows the cell voltage distribution at the point P2 on the line L3 of the required degree k1 (L3). In this case, the difference between the average cell voltage and the minimum cell voltage is the same as that shown in FIG. 7A. However, since the cell standard deviation at the point P2 is smaller than the point P1, it is more near the average cell voltage. Cells are distributed in a narrow voltage range. In such a case, in the state of FIG. 7 (b), the degree of isolation of the cell with the lowest voltage with respect to the cell group in the vicinity of the average is higher, so the degree of request is higher as k1 (L2) <k1 (L3). Set.

  FIG. 5 is a diagram illustrating an example of the capacity adjustment capability improvement request level k2 based on the data obtained in step S13, where the vertical axis indicates the capacity adjustment capability increase request level k2 and the horizontal axis indicates the system usage time ratio. . When the system usage time ratio is small, the capacity adjustment opportunities are also reduced. Therefore, the capacity adjustment capability improvement request level k2 is set larger so that the capacity adjustment is completed in a short time. When the system usage time ratio is equal to or greater than a predetermined value, the request degree k2 = 1 is set and the improvement request is turned off.

  FIG. 6 is a diagram illustrating an example of the capacity adjustment capability improvement request level k3 based on the data obtained in step S14. The vertical axis represents the capacity adjustment capability improvement request level k3, and the horizontal axis represents the capacity deterioration coefficient (%). ing. Since the capacity adjustment time is calculated on the assumption that the assembled battery 2 is new, if the capacity is reduced due to deterioration, the actual capacity adjustment time is calculated unless the capacity adjustment current is reduced accordingly. It will not be the capacity adjustment time as I did.

  For example, when the capacity deterioration coefficient is 80%, the capacity adjustment capability improvement requirement k3 is set to 0.8. The capacity adjustment capability improvement request level k3 is 1 or less, and the larger the capacity degradation coefficient (%), the smaller the capacity adjustment capability is requested. That is, the capacity adjustment capability improvement requirement k1, k2 with k1, k2 ≧ 1 acts to increase the capacity adjustment capability, while the capacity adjustment capability improvement requirement k3 acts to decrease the capacity adjustment capability, It can be considered as a correction coefficient that corrects the effects of the required degrees k1 and k2.

Thus, if each capacity adjustment capability improvement request | requirement k1-k3 is obtained, the final capacity adjustment capability improvement request | requirement k will be calculated | required by following Formula.
k = k1 × k2 × k3

  Returning to FIG. 3, in step S <b> 16, the assembled battery target SOC at the time of capacity adjustment is calculated based on the capacity adjustment capability improvement request degree k calculated in step S <b> 15. FIG. 8 shows an example of the assembled battery target SOC setting map, where the vertical axis represents the assembled battery target SOC (%), and the horizontal axis represents the above-described capacity adjustment capability improvement request degree k as a percentage. In this case, capacity improvement is not required when k = 100 (%), and capacity improvement is required when k> 100 (%).

  In FIG. 8, the value of the assembled battery target SOC when k = 100 (%) is the assembled battery target SOC before the setting is changed according to the capacity adjustment capability improvement request degree k. This will be called the target SOC. In the example illustrated in FIG. 8, the value of the assembled battery target SOC increases at a constant rate as k increases, and the upper limit value of the assembled battery target SOC is reached when k = k ′. When k> k ′, the upper limit is maintained.

  In step S17, the input restriction SOC is determined based on the assembled battery target SOC calculated in step S16. The assembled battery target SOC is a parameter for controlling charging / discharging of the assembled battery 2 on the vehicle system side. Charge / discharge control is performed so that the SOC of the assembled battery 2 falls within a predetermined width centered on the set assembled battery target SOC. That is, when the SOC of the assembled battery 2 is larger than the assembled battery target SOC, a discharge command is issued, and conversely, when the SOC is smaller than the assembled battery target SOC, a charging command is issued. As a result, the SOC of the assembled battery 2 is controlled to fall within a predetermined range centered on the assembled battery target SOC.

  Such control is performed by setting an input / output limit value as shown in FIG. 9 according to the SOC of the battery pack 2. FIG. 9 shows an example when the assembled battery target SOC is 60%. The vertical axis represents the input / output limit value (kW), and the horizontal axis represents the SOC (%) of the assembled battery 2. . The upper line L11 is a line that defines an input limit value on the input (charge) side, and the lower line L12 is a line that defines an output limit value on the output (discharge) side. At the time of charging / discharging, the input / output value is controlled to take a value between the line L11 and the line L12.

  When the SOC of the battery pack 2 rises from 60% to x2 (%), the input limit value starts decreasing, and when the SOC reaches 80%, the input limit value = 0 and input is not permitted. On the other hand, when the SOC decreases to x1 (%), the output limit value (absolute value of the limit value) starts to decrease, and when SOC = 40%, the output limit value = 0 and the output is not permitted. Therefore, the SOC of the battery 2 is controlled within a range of 40% to 80% centering on the assembled battery target SOC = 60%. Here, the SOC with the input limit value = 0 is referred to as the input limit SOC, and the SOC with the output limit value = 0 is referred to as the output limit SOC.

  In step S17, the input restriction SOC is changed based on the assembled battery target SOC calculated in step S16, and the SOC of the assembled battery 2 at the time of capacity adjustment is increased as compared with the normal time. As a method for increasing the SOC by changing the input restriction SOC, for example, there are methods as shown in FIGS.

  10A and 10B are diagrams for explaining the first method. FIG. 10A is a diagram showing a relationship between the assembled battery target SOC and the input limit SOC, and FIG. 10B is a diagram showing the relationship between the assembled battery SOC and the input / output limit value. FIG. When the assembled battery target SOC increases, the actual assembled battery SOC cannot be increased unless the input limit value is also changed in conjunction with it, so the input limit SOC is set as shown in FIG.

  When the input restriction SOC in the normal state (assembled battery target SOC = 60%) is set to 80%, when the assembled battery target SOC becomes higher than 60%, the input restricted SOC is set at a constant rate as shown in FIG. increase. The input restriction SOC when the assembled battery target SOC = 80% is set to 90%. Setting the input restriction SOC as shown in FIG. 10 (a) means that the inclined portion (the portion of x2 to 80%) of the line L11 in FIG. 10 (b) is shifted to the right side as shown by the arrow. ing.

  At this time, the increase amount of the input restriction SOC is set smaller than the increase amount of the assembled battery target SOC. For example, when the assembled battery target SOC increases from 60% to 10%, the input restriction SOC is increased from 80% to 5%, and when the assembled battery target SOC increases from 60% to 20%, the input restriction SOC is Increased from 80% to 10%. As a result, the difference between the assembled battery target SOC and the input restriction SOC is 20% when the assembled battery target SOC = 60%, but becomes 15% when the assembled battery target SOC = 70%. When the target SOC is 80%, it decreases to 10%. Therefore, the SOC of the assembled battery 2 is increased by increasing the assembled battery target SOC, and overvoltage (overcharge) can be prevented by setting the shift amount of the input restriction SOC to be smaller than the shift amount of the assembled battery target SOC. .

  Further, in the first method, not only the upper limit side is shifted to the right side, but also the lower limit side (the inclined portion of the line L12) is shifted to the right side. That is, it corresponds to shifting the entire usable area of the assembled battery 2 to the right side. As a result, the SOC of the assembled battery during capacity adjustment increases, and the voltage of the assembled battery (that is, the cell voltage of each cell) increases. As the cell voltage of each cell increases, the current flowing through the capacity adjustment resistor R10 increases, and the capacity adjustment capability is improved. In the case of the control change as shown in FIG. 10, a large logic change is not necessary with respect to the conventional control method, and it can be easily dealt with.

  11A and 11B are diagrams for explaining the second method. FIG. 11A is a diagram similar to FIG. 10A, and FIG. 11B is a diagram showing the relationship between the assembled battery SOC and the input / output limit value. . In the second method, as shown in FIG. 11B, only the upper limit side (inclined portion of the line L11) of the battery usable area is shifted to the right side in the figure. When set in this way, the SOC of the assembled battery 2 is increased and the battery usable area is widened, so that the range of use of the hybrid is widened and fuel efficiency can be improved.

  FIG. 12 is a diagram for explaining the third method. In the third method, the upper limit side is not changed as in the first and second methods described above, and only the lower limit side (inclined portion of the line L12) corresponds to the shift of the assembled battery target SOC as shown in FIG. To the right in the figure. In the case of the third method, since the upper limit side is not shifted to the high SOC side, it is not necessary to add measures against the influence on the battery life and overvoltage (overcharge).

  When the input limit value is set as described above in step S17, the process proceeds to step S18 to start capacity adjustment. In step S19, it is determined for each cell whether or not capacity adjustment has been completed. When capacity adjustment has been completed for all cells, a series of capacity adjustment processing is completed.

  In the capacity adjustment in step S18, since the assembled battery target SOC is set higher than usual as described above, the actual assembled battery SOC is increased, and the voltage of each cell is increased accordingly. As the cell voltage increases, the value of the current flowing through the capacity adjustment resistor R10 (see FIG. 2) increases, and the capacity adjustment capability is enhanced.

  FIG. 13 shows (a) a conventional capacity adjustment situation and (b) a capacity adjustment situation in the present embodiment, and the horizontal axis represents time. In the conventional case, as shown in FIG. 13 (a), even if the capacity adjustment state is turned on at time t1, since the assembled battery target SOC is the same as when it is off, the cell average voltage is also set to the same value V1 as when it is off. Maintained. On the other hand, in the case of the present embodiment, when the capacity adjustment state is turned on, the assembled battery target SOC is set higher than normal (in the case of off), so the cell average voltage is also changed from V1 to V2 (> V1). The current (capacitance adjustment current) flowing through the capacitance adjustment resistor R10 increases from i1 to i2 (> i1). As a result, the capacity adjustment time is shortened, and in the present embodiment, the capacity adjustment is completed at the time t3 (<t3) in the present embodiment.

  Therefore, for example, when it is desired to quickly adjust the capacity such as when the usage time of the vehicle is extremely short, the capacity adjustment capability is increased by setting the assembled battery target SOC high, and the vehicle system is not yet finished before the capacity adjustment is completed. It is possible to avoid such a situation that the capacity adjustment cannot be sufficiently performed due to the turning off.

  As described above, the assembled battery target SOC according to the degree of variation in each cell voltage as in the required levels k1 to k3, the usage time ratio of the system, and the capacity adjustment improvement required level set according to the capacity deterioration state Therefore, it is possible to adjust the capacity appropriately according to the battery status and usage status.

  That is, since the capacity adjustment improvement requirement k1 is set to be higher as the variation in each cell voltage is larger, the cell voltage distribution (cell voltage variation) generated by the self-discharge amount variation is efficiently eliminated (adjusted). be able to. In addition, the capacity adjustment capability improvement requirement k2 is set to be larger as the system usage time ratio is smaller. As a result, the capacity adjustment capability can be improved when the vehicle is used for a short time. In addition, the cell voltage distribution can be kept in a normal state without variations. Furthermore, by introducing the capacity adjustment capability improvement requirement k3 according to the battery capacity deterioration, it is possible to consider that the allowable range of the SOC difference and standard deviation differs when the capacity deterioration progresses, and excessive capacity adjustment is performed. Can be prevented.

  In the above-described embodiment, the capacity adjustment capability improvement requirement k3 functions to correct the effect of the requirement k based on the capacity deterioration coefficient. However, as shown in FIG. 18, the maximum cell capacity and the average cell capacity The assembled battery target SOC may be corrected according to the difference between the two. The vertical axis in FIG. 18 is a correction coefficient for correcting the assembled battery target SOC, and becomes smaller as the difference between the maximum cell capacity and the average cell capacity increases, and acts to reduce the assembled battery target SOC calculated in FIG. To do. As a result, it is possible to prevent a high capacity cell from being overcharged.

-Second Embodiment-
In the first embodiment described above, the capacity adjustment capability is improved by changing the input limit SOC and the output limit SOC as shown in FIGS. 10 to 12 and shifting the upper limit of input and the lower limit of output to the high SOC side. I planned. On the other hand, in the second embodiment described below, the average battery voltage is increased by setting the input restriction start timing later than usual as shown in FIG. 14 without changing the input restriction SOC or the output restriction SOC. I did it.

  The line L11 is a line for setting an input limit value at a normal time, and the line L21 is a line for setting an input limit value at the time of capacity adjustment. x2 and x3 are SOCs at which input restriction is started, and x3 of the line L21 is obtained by shifting x2 of the line L11 to the high SOC side. Note that the position of the input restriction SOC (position where the input restriction value = 0) is the same in the lines L11 and L21, so that it is possible to avoid an overvoltage.

  If x3 at which the input restriction is started is shifted to the high SOC side as indicated by a line L21 in FIG. 14, the timing at which the input restriction is started becomes a higher SOC than usual, so that the average battery voltage increases. As a result, the capacity adjustment current is increased, the capacity adjustment capability is improved, and the capacity adjustment time is shortened. Note that since the input restriction SOC at which the input restriction value is 0 is not changed, overvoltage can be avoided even if the SOC is controlled to be higher.

  FIG. 15 is a flowchart for explaining the control operation of the second embodiment. The processing from step S11 to step S15 is the same as the processing from step S11 to step S15 in FIG. 3, and description thereof is omitted here. In step S26, the input restriction start SOC (the SOC at the timing at which the above input restriction is started) is calculated based on the capacity adjustment capability improvement request degree calculated in step S15.

  FIG. 16 is a diagram illustrating an example of the input restriction start SOC setting map. In FIG. 16, the horizontal axis indicates the capacity adjustment capability improvement required degree (%), and the left end indicates the required degree of 100% as in the case of FIG. When the capacity adjustment capability improvement request level is 100%, the input restriction start SOC is a normal value, but as the capacity adjustment capability improvement request level increases, the input limit start SOC increases at a constant rate. If the capacity adjustment capability improvement request level becomes a predetermined value (for example, the same value as the input restriction SOC), then it becomes a constant value.

  In step S27, the duty of the cooling fan 310 (see FIG. 1) for cooling the assembled battery 2 is increased in consideration of the increase in heat generation accompanying the increase in capacity adjustment current. 17A and 17B are diagrams for explaining the duty control of the cooling fan 310. FIG. 17A shows the relationship between the battery temperature and the cooling fan duty, and FIG. 17B shows the capacity adjustment capability improvement requirement (%) and the duty increase amount (%). ).

  As shown in FIG. 17A, the cooling fan duty is controlled in five steps according to the battery temperature (° C.), and increases stepwise as the temperature increases. Here, the range of increase ΔD is changed as shown in FIG. 17B according to the magnitude of the required capacity adjustment capability improvement. When the capacity adjustment capability improvement requirement is 100%, the capacity adjustment current value is the same as in the conventional case, so the duty increase amount is 0 (%). On the other hand, when the capacity adjustment capability improvement request level k is 100 <k ≦ ka, the duty increase amount is set to D1 (%).

  In this case, the increase width of FIG. 17A is increased by D1 (%). That is, the increase width is increased from ΔD to ΔD · (100 + D1) / 100. Similarly, when the capacity adjustment capability improvement requirement k is ka <k ≦ kb, the duty increase amount is D2 (%), and when kb <k, the duty increase amount is D3 (%). As a result, even if the amount of heat generation increases as the capacity adjustment capability increases, the duty of the cooling fan is increased according to the improvement in capacity adjustment capability, so that an increase in battery temperature can be suppressed.

  If the process of step S27 is complete | finished, the process of step S18 and step S19 will be performed in order. Note that the processing of step S18 and step S19 is the same as the processing of the step with the same sign in FIG.

  As described above, according to the second embodiment, during the capacity adjustment, by changing the input (charging) restriction start timing to the high SOC side, the condition for increasing the battery voltage compared to the normal time increases. Accordingly, the capacity adjustment capability can be increased. In addition, since the duty of the cooling fan is increased in consideration of an increase in the amount of heat radiation accompanying the improvement in capacity adjustment capability, the temperature impact on the assembled battery 2 can be reduced.

  In the correspondence between the embodiment described above and the elements of the claims, the vehicle systems CPU 304 and CPU 103 constitute charge / discharge control means, the CPU 103 constitutes setting means and cooling capacity control means, and the cooling fan 310 constitutes cooling means. . The above description is merely an example, and when interpreting the invention, there is no limitation or restriction on the correspondence between the items described in the above embodiment and the items described in the claims.

It is a figure which shows 1st Embodiment of the capacity | capacitance adjustment apparatus by this invention. 3 is a diagram showing details of a capacity adjustment unit 102. It is a flowchart which shows an example of the capacity | capacitance adjustment control in this Embodiment. It is a figure which shows an example of capacity adjustment capability improvement request | requirement degree k1. It is a figure which shows an example of the capacity | capacitance adjustment capability improvement requirement k2. It is a figure which shows an example of capacity adjustment capability improvement request | requirement degree k3. FIG. 4 qualitatively shows the states of the points P1 and P2 in FIG. 4, where (a) shows the cell voltage distribution at the point P1, and (b) shows the line L3 of the required level k1 (L3). The cell voltage distribution at the upper point P2 is shown. It is a figure which shows an example of an assembled battery target SOC setting map. It is a figure which shows the relationship between SOC of assembled electricity, and an input-output limit value. It is a figure explaining the 1st method of raising assembled battery target SOC, (a) is a figure showing the relation between assembled battery target SOC and input restriction SOC, and (b) is assembled battery SOC and input / output limit value. It is a figure which shows the relationship. It is a figure explaining the 2nd method which raises assembled battery target SOC, (a) is a figure which shows the relationship between assembled battery target SOC and input restriction | limiting SOC, (b) is assembled battery SOC, input / output limit value, and It is a figure which shows the relationship. It is a figure explaining the 3rd method of raising assembled battery target SOC, and shows the relationship between assembled battery SOC and an input-output limit value. It is a figure which compares and shows a capacity | capacitance adjustment condition, (a) The conventional case is shown, (b) The case of this Embodiment is shown. It is a figure explaining the setting change of an input restriction start timing. It is a flowchart explaining the control operation of 2nd Embodiment. It is a figure which shows an example of an input restriction start SOC setting map. It is a figure explaining the duty control of the cooling fan 310, (a) shows the relationship between battery temperature and a cooling fan duty, (b) is capacity adjustment capability improvement request | requirement (%) and duty increase amount (%). Showing the relationship. It is a figure which shows an example of the assembled battery target SOC correction coefficient using the difference of the maximum cell capacity and the average cell capacity.

Explanation of symbols

  1: battery control unit, 2: assembled battery, 3: vehicle system, 11: switching element, 12, 22, 32: capacity adjustment circuit, 101: cell voltage detection unit, 102: capacity adjustment unit, 103: CPU, 104: Memory 201: Current sensor 202: Voltage sensor 203: Temperature sensor 301: Inverter 302: Auxiliary machine system 304: Vehicle system CPU C1-C3: Cell M: Motor R10: Capacity adjustment resistor

Claims (10)

In the capacity adjustment device for an electric vehicle provided with a capacity adjustment resistance of a fixed resistance value for each cell constituting the assembled battery,
Charge / discharge control means for controlling charge / discharge of the assembled battery to control the SOC (State Of Charge) of the assembled battery within a predetermined range including the assembled battery target SOC;
Setting means for setting the assembled battery target SOC during capacity adjustment higher than the assembled battery target SOC during non-capacity adjustment;
Said setting means calculates a standard deviation of the difference and the cell voltage between the average cell voltage and the minimum cell voltage of the battery pack, the battery pack target SOC to the large set in the higher capacity adjustment the difference is large, the standard The capacity adjustment device, wherein the battery pack target SOC during capacity adjustment is set larger as the deviation is smaller . In the capacity adjustment device for an electric vehicle provided with a capacity adjustment resistance of a fixed resistance value for each cell constituting the assembled battery,
Charge / discharge control means for controlling charge / discharge of the assembled battery to control the SOC (State Of Charge) of the assembled battery within a predetermined range including the assembled battery target SOC;
Setting means for setting the assembled battery target SOC during capacity adjustment higher than the assembled battery target SOC during non-capacity adjustment;
The setting means calculates a difference between the average cell voltage and the minimum cell voltage of the assembled battery, and a ratio of the vehicle start time and the sum of the vehicle start time and the non-start time, and the capacity is being adjusted as the difference increases. When the battery pack target SOC is set to be larger and the ratio is smaller than a predetermined value, the battery pack target SOC during capacity adjustment is set to be larger as the ratio is smaller. . The capacity adjustment apparatus according to claim 1 or 2 ,
The charge / discharge control means controls to limit the amount of charge when the SOC exceeds the upper limit of the predetermined range, and limits the amount of discharge when the SOC falls below the lower limit of the predetermined range,
The setting means shifts an upper limit and a lower limit of the predetermined range to a high SOC side during capacity adjustment. The capacity adjustment apparatus according to claim 1 or 2 ,
The charge / discharge control means controls to limit the amount of charge when the SOC exceeds the upper limit of the predetermined range, and limits the amount of discharge when the SOC falls below the lower limit of the predetermined range,
The setting means shifts the upper limit of the predetermined range to the high SOC side during capacity adjustment. The capacity adjustment apparatus according to claim 1 or 2 ,
The charge / discharge control means controls to limit the amount of charge when the SOC exceeds the upper limit of the predetermined range, and limits the amount of discharge when the SOC falls below the lower limit of the predetermined range,
The setting means shifts the lower limit of the predetermined range to the high SOC side during capacity adjustment. The capacity adjustment apparatus according to claim 3 or 4 ,
The setting means sets the upper limit shift amount of the predetermined range to be smaller than a difference between the assembled battery target SOC during capacity adjustment and the assembled battery target SOC during non-capacity adjustment. apparatus. The capacity adjustment apparatus according to claim 1 or 2 ,
The charge / discharge control means starts limiting the charge amount in the first SOC, and controls the charge amount to zero in the SOC exceeding the second SOC higher than the first SOC,
The capacity adjustment device, wherein the setting means shifts the first SOC to a high SOC side during capacity adjustment. In capacity adjustment apparatus according to any one of claim 1 to 7
Cooling means for cooling the assembled battery;
A capacity adjustment device, further comprising: a cooling capacity control means for setting the cooling capacity of the cooling means during capacity adjustment higher than the cooling capacity during non-capacity adjustment. In the capacity adjustment apparatus as described in any one of Claims 1-8 ,
The capacity adjustment device, wherein the setting means sets the assembled battery target SOC smaller as a difference between the maximum cell capacity and the average cell capacity is larger. In capacity adjustment apparatus according to any one of claims 1 to 9
Further provided is a deterioration calculation means for calculating the degree of capacity deterioration of the assembled battery,
The setting means sets the difference between the assembled battery target SOC during capacity adjustment and the assembled battery target SOC during non-capacity adjustment to be smaller as the calculated degree of capacity deterioration is larger. Adjustment device.

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