JP2020150760A - Battery control unit - Google Patents

Abstract

To solve the problem in which: when there is a voltage difference between electric cells, equalization processing is performed, and when the equalization processing is performed, there is a possibility of reduction in the state of charge of the electric cells.SOLUTION: In step 100, the current SOCs of electric cells 111 are obtained and denoted as SOCbefore(i). In step 101, the SOC values of the electric cells 111 are compared with each other, and when the difference exceeds an allowable value, the electric cells 111 are subjected to equalization processing. In steps 102 to 104, the SOC values SOCafter(i) of the electric cells 111 after execution of single balancing are estimated. In step 105, the average SOC value SOCave of a battery pack 110 is obtained, and in step 106, the average SOC value SOCave is compared with a threshold SOCLimit, and when the average SOC value SOCave is less than the threshold SOClimit, the step proceeds to step 107, and the equalization processing is determined not to be executed.SELECTED DRAWING: Figure 4

Description

The present invention relates to a battery control device.

In general, in an assembled battery composed of a plurality of cells connected in series, an equalization process for equalizing the voltage of each cell is performed in order to prevent variations in the cells due to deterioration.
In Patent Document 1, a threshold value for determining whether or not to perform equalization processing based on the capacity of the assembled battery is calculated, and the calculated threshold value is the voltage difference between the maximum voltage and the minimum voltage between the cells. It is disclosed to control the implementation of the equalization process in comparison.

JP-A-2009-711936

In the technique of Patent Document 1, if there is a voltage difference between the cells, the equalization process is always performed, and the equalization process may be performed to lower the charged state of the cells. Therefore, for example, in a vehicle equipped with a battery control device, there is a risk that the power required for starting cannot be obtained.

The battery control device according to the present invention includes an assembled battery in which a plurality of cells are connected in series, an equalization processing unit that performs an equalization process for equalizing the charging states of the plurality of cells, and the plurality of cells. The equalization processing unit is provided with an equalization estimation unit that calculates an estimated value of the charging state when the plurality of cells are equalized based on the charging state of the above. If the estimated value calculated by the equalization estimation unit is less than a predetermined value, the equalization processing by the equalization processing unit is not performed.

According to the present invention, it is possible to suppress the equalization process and prevent a decrease in the charged state of the cell.

It is a figure which shows the vehicle control system which used the battery control device. It is a figure which shows the circuit structure of the cell cell control part. It is a figure which shows the example of the SOC table. It is a flowchart which shows the 1st operation of the equalization estimation processing. It is a figure explaining the equalization process. It is a flowchart which shows the 2nd operation of the equalization estimation processing. It is a figure which shows the correspondence table of the SOC change amount and the equalization processing time. It is a flowchart which shows the determination process of the imbalance diagnosis in the assembled battery control unit.

FIG. 1 is a diagram showing a vehicle control system using the battery control device 100.
First, the configuration of the battery control device 100 will be described. The battery control device 100 includes an assembled battery 110 composed of a plurality of cells 111, a cell management unit 120 that monitors the state of the cell 111, a current detection unit 130 that detects the current flowing through the battery control device 100, and an assembled battery. It includes a voltage detection unit 140 that detects the total voltage of 110, and a battery control unit 150 that controls the battery 110. The assembled battery control unit 150 transmits the battery voltage and temperature of the cell 111 transmitted from the cell management unit 120, the current value flowing through the battery control device 100 transmitted from the current detection unit 130, and the voltage detection unit 140. The total voltage value of the assembled battery 110 is input, and the state of the assembled battery 110 is detected based on the input information. Further, the result of the process performed by the assembled battery control unit 150 is transmitted to the unit battery management unit 120 and the vehicle control unit 200.

The vehicle control unit 200 controls the inverter 400 connected to the battery control device 100 via the relays 300 and 310 based on the information of the assembled battery control unit 150. While the vehicle is running, the battery control device 100 is connected to the inverter 400 and drives the motor generator 410 based on the energy stored in the assembled battery 110.

The assembled battery 110 is configured by electrically connecting a plurality of single batteries 111 (lithium ion batteries) capable of storing and discharging electric energy (charging / discharging DC power) in series. The output voltage of one cell 111 is 2.5 to 4.2 V (average output voltage: 3.6 V).

The unit batteries 111 constituting the assembled battery 110 are grouped into a predetermined number of units for management and control. The grouped cell cells 111 are electrically connected in series to form the cell group 112a and 112b. The predetermined number of units may be divided into equal categories, for example, 1, 4, 6, ..., Or may be combined into a compound category, such as combining 4 and 6. .. Further, the cell group 112a on the high potential side and the cell group 112b on the low potential side are electrically connected in series.

The cell management unit 120 that monitors the state of the cell 111 that constitutes the assembled battery 110 is composed of a plurality of cell control units 121a and 121b. The cell control units 121a and 121b are assigned to the grouped cell groups 112a and 112b, respectively. The cell control units 121a and 121b operate by receiving electric power from the assigned cell groups 112a and 112b, and monitor and control the state of the cell cells 111 constituting the cell groups 112a and 112b.

In the present embodiment, for the sake of simplicity, the assembled battery 110 includes a total of eight cell batteries 111, and the four cell batteries 111 are electrically connected in series to form two cell group 112a, 112b. In addition, the cell groups were electrically connected in series.

The assembled battery control unit 150 includes a measured value of the battery voltage and temperature of the cell 111 output from the cell management unit 120, a diagnosis result of whether the cell 111 is overcharged or overdischarged, and the cell management unit 120. An abnormal signal that is output when a communication error occurs is input to. Further, a plurality of signals including a current value from the current detection unit 130, a total voltage value of the assembled battery 110 output from the voltage detection unit 140, and a signal output from the vehicle control unit 200 which is a higher-level control device. Is entered. The assembled battery control unit 150 executes the SOC calculation of the cell 111 based on the input information, the internal resistance of the cell 111 stored in advance, and the relationship between the SOC and OCV shown in FIG. 3 described later. To do. Then, the calculation result and the command based on the calculation result are output to the cell management unit 120 and the vehicle control unit 200.

Further, the assembled battery control unit 150 includes an equalization estimation unit 150a and an equalization processing unit 150b. The equalization estimation unit 150a performs the equalization estimation process shown in FIGS. 4 and 6 described later. The equalization estimation process simulates whether the cell 111 should be equalized prior to the implementation of the equalization process. The equalization processing unit 150b performs an operation for controlling the charge / discharge amount according to the result of the simulation by the equalization estimation unit 150a, and operates the equalization circuit 127 described later to equalize the cell 111. To do.

The assembled battery control unit 150 and the cell management unit 120 transmit and receive signals by the signal communication means 160 via an insulating element 170 such as a photocoupler. The reason why the insulating element 170 is provided is that the operating power supply differs between the assembled battery control unit 150 and the cell management unit 120. That is, the cell management unit 120 operates by receiving electric power from the assembled battery 110, whereas the assembled battery control unit 150 uses a battery for an in-vehicle auxiliary machine (for example, a 14V system battery) as a power source. The insulating element 170 may be mounted on the circuit board that constitutes the cell management unit 120, or may be mounted on the circuit board that constitutes the assembled battery control unit 150. Of course, the cell management unit 120 and the assembled battery control unit 150 may be mounted on one circuit board. Depending on the system configuration, the insulating element 170 may be omitted.

The communication means between the assembled battery control unit 150 and the unit battery control units 121a and 121b in the present embodiment will be described. The cell control units 121a and 121b are connected in series in descending order of potential of the cell groups 112a and 112b monitored by each. The signal transmitted by the assembled battery control unit 150 is input to the unit battery control unit 121a by the signal communication means 160 via the insulating element 170. Similarly, the output of the cell control unit 121a and the input of the cell control unit 121b are also connected by the signal communication means 160 to transmit a signal. In the present embodiment, the cell-cell control unit 121a and the cell-cell control unit 121b do not pass through the insulating element 170, but may pass through the insulating element 170. Then, the output of the cell control unit 121b is transmitted by the signal communication means 160 via the insulating element 170 and the input of the assembled battery control unit 150. As described above, the assembled battery control unit 150, the cell cell control unit 121a, and the cell cell control unit 121b are connected in a loop by the signal communication means 160. This loop connection may also be referred to as a daisy chain connection, a beaded connection, or a potato-shaped connection. Although an example in which the cell control unit 121a and the cell control unit 121b are connected in a loop shape is shown here, the cell cell control unit 150 and the cell cell control unit 121a are not necessarily in the loop shape. Any form may be used as long as the cell control unit 121b is connected.

FIG. 2 shows the circuit configurations of the cell control units 121a and 121b in the present embodiment. The cell control units 121a and 121b are equalization circuits 127 composed of a bypass resistor 122 and a bypass switch 123, a SW drive circuit 125 for driving the bypass switch 123, and a voltage for measuring the battery voltage of the cell 111 to be managed. It has a detection circuit 124. Further, the cell control units 121a and 121b control the cell control units 121a and 121b based on the information from the power supply 126 for operating the cell control units 121a and 121b and the assembled battery control unit 150. It has a signal input / output circuit 129 that transmits / receives a signal to / from the circuit 128, the assembled battery control unit 150, or the adjacent single battery control unit 121.

The control circuit 128 receives the voltage acquisition command and the equalization processing information transmitted from the assembled battery control unit 150 via the signal input / output circuit 129, and is based on the battery voltage detected by the voltage detection circuit 124 and the battery voltage thereof. The information is output to the signal input / output circuit 129. Then, the control circuit 128 controls the SW drive circuit 125 based on the detected battery voltage and the information from the equalization processing unit 150b.

The equalization circuit 127 discharges the single battery 111 having a high SOC among the single batteries 111 constituting the single battery group 112. That is, by turning on the bypass switch 123 connected in parallel to the unit cell 111 to be discharged and using the bypass resistor 122, the unit cell 111 is forcibly discharged and the target SOC (target SOC). Reduce to. Here, the target SOC is when any one of the plurality of cell cells 111 constituting the assembled battery 110 exceeds the allowable SOC range, or the SOC of the cell cells 111 constituting the cell group 112. This is a predetermined SOC that is set to eliminate the variation that exceeds the permissible limit.

The control circuit 128 calculates the time (discharge end condition) required to secure a predetermined discharge amount in the equalization process, and ends the discharge by the equalization circuit 127 when the calculated time elapses. An example will be described in which the time required for discharging the cell 111 is set as the discharge end condition, but the discharge end condition is not limited to this.

When time has passed since the discharge end condition was calculated, the state of the battery may change due to self-discharge or changes in the environment. Therefore, the discharge end condition is not determined only once at the beginning, but a certain amount of time has passed. After that, it is desirable to make a decision again and perform the equalization process in the latest state. Therefore, the equalization process is divided. For example, one equalization process is set to 1 hour, and this process is repeated until the discharge end condition is reached. Here, the equalization processing time for one time does not necessarily have to be one hour, and an arbitrary time such as several ms to several hours may be set. Further, the equalization processing time may be variable instead of fixed.

FIG. 3 is a diagram showing an example of an SOC table stored in the storage unit 500. The SOC table is a data table that describes the correspondence between the OCV (Open Circuit Voltage) of the cell 111 and the SOC of the cell 111. The data format may be arbitrary, but here, a graph format data example is shown, but the correspondence between OCV and SOC may be expressed by using a mathematical formula or the like. It is characteristic information indicating the correspondence between OCV and SOC, and may be any means capable of converting OCV to SOC or SOC to OCV.

OCV is the voltage of the cell 111 when there is no load. The voltage between the terminals of the cell 111 measured at the timing before the relays 300 and 310 are closed, or when the relays 300 and 310 are closed but the charging / discharging of the assembled battery 110 is not started, can be determined as OCV. .. Further, when the assembled battery 110 is being charged or discharged but its current value is weak, it can be regarded as OCV.

FIG. 4 is a flowchart showing the first operation of the equalization estimation process of the equalization estimation unit 150a in the assembled battery control unit 150.
The equalization estimation process simulates whether the cell 111 should be equalized prior to the execution of the equalization process. For example, the equalization process is performed at predetermined time intervals or in a state where the ignition key of the vehicle is on. At any time when the implementation of is requested.

In step 100 of FIG. 4, the SOC of each current cell 111 is obtained. If the assembled battery 110 is in a stable state with no load, the SOC can be estimated from the OCV measurement results of all the cells 111 based on the correlation between the SOC and the OCV shown in FIG. Further, when it is not in the no-load state, SOC may be estimated and calculated from information such as battery voltage, current, and temperature. The SOC of each cell 111 thus obtained is designated as SOC before (i). Here, i indicates the number of the cell 111.

Next, the process proceeds to step 101, the SOC values of each cell 111 are compared, and the degree of variation is measured. As an example, the minimum SOC value is detected, and then the difference between the minimum SOC value and the SOC value of each cell 111 is measured. If this difference exceeds the permissible value, the cell 111 is subject to the equalization estimation process. In this way, it is determined whether or not the all-cells 111 are subject to the equalization estimation process.

In step 102, the SOC change amount ΔSOCaux (i) of each cell 111 due to the power supply to the accessories is obtained. This is calculated by the following equation (1). Here, as an example, it is assumed that charging / discharging to the assembled battery 110 is limited to power supply to the auxiliary equipment, and a constant current Iaux flows through the auxiliary equipment.
ΔSOCaux (i) ＝ Iaux × t / Qmax (i) ・ ・ ・ (1)
Here, Qmax (i) indicates the full charge capacity [Ah] of each cell 111. Further, let t be one equalization estimation processing time. If the discharge direction is negative, Iaux <0. Here, the charge / discharge to the assembled battery 110 is limited to the power supply to the auxiliary equipment, but if the charge / discharge behavior can be predicted in the equalization estimation process, the power supply to the auxiliary equipment is limited. Not done.

Next, in step 103, the SOC reduction amount ΔSOCbal (i) of each cell 111 due to the discharge of the equalization estimation process is obtained by the following equation (2) in the case of the cell 111 subject to the equalization estimation process. In the case of the cell 111 which is not the target of equalization estimation processing, it is calculated by the following equation (3). Here, the current flowing through the equalization circuit 127 is assumed to be Ibal, but if the current has different characteristics for each equalization circuit 127, a different value may be assumed for each circuit, or the voltage of the cell 111 may be changed. The current value may be dynamically changed based on the current value.
ΔSOCbal (i) ＝ Ibal × t / Qmax (i) ・ ・ ・ (2)
ΔSOCbal (i) ＝ 0 ・ ・ ・ (3)
Here, if the discharge direction is negative, Ibal <0.

In step 104, the SOC value SOC after (i) of each cell 111 after the equalization estimation process is estimated and obtained by using the processing results of steps 102 to 103. The SOC estimated value SOCafter (i) of each cell 111 after one equalization estimation process is the SOC estimated change amount ΔSOCaux (i) of each cell 111 obtained in step 102 and the equalization obtained in step 103. It can be expressed by the equation (4) by using the SOC estimated decrease amount ΔSOCbal (i) of each cell 111 by the estimation process.
SOCafter (i) ＝ SOCbefore (i) ＋ ΔSOCaux (i) ＋ ΔSOCbal (i) ・ ・ ・ (4)

In step 105, the average SOC value SOCave after the equalization estimation process of the assembled battery 110 is obtained. Using the SOC estimated value SOCafter (i) of each cell 111 after the equalization estimation process obtained in step 104, the average SOC value of the assembled battery 110 is obtained by the equation (5).

In step 106, this average SOC value SOCave is compared with the threshold SOC Limit. If the average SOC value SOCave is less than the threshold SOC Limit, the process proceeds to step 107, and it is determined not to perform the equalization process. If the average SOC value SOCave is equal to or greater than the threshold value SOC Limit, the process proceeds to step 108, and it is determined to perform the equalization process.

In the next step 109, the storage unit 500 stores that the equalization process determined in step 107 is not performed or that the equalization process determined in step 108 is performed.

After performing the above equalization estimation processing, the process shifts to the processing of the equalization processing unit 150b in the assembled battery control unit 150, and the storage unit 500 indicates that the equalization processing unit 150b does not perform the equalization processing. If it is stored in, the equalization process is not performed. As a result, it is possible to determine that the average SOC value is lower than the threshold value after the equalization estimation process before actually performing the equalization process, and prevent the SOC of the cell 111 from being lowered due to the equalization process. ..

Further, the equalization processing unit 150b executes the equalization processing when the storage unit 500 stores that the equalization processing is to be performed. The equalization processing unit 150b transmits information regarding the equalization processing to the control circuit 128. The control circuit 128 controls the SW drive circuit 125 based on the detected battery voltage and the information from the equalization processing unit 150b. That is, by turning on the bypass switch 123 connected in parallel to the unit cell 111 to be discharged and using the bypass resistor 122, the unit cell 111 is forcibly discharged and the target SOC (target SOC). Reduce to.

As described above, when the estimated value of the charging state is less than the predetermined value, it is presumed that the charging state required for the vehicle cannot be obtained if the equalization process is performed, and the equalization process is stopped. As a result, the vehicle can be started and continued to run. On the other hand, when the estimated value of the charging state is equal to or higher than a predetermined value, it is estimated that the charging state required for the vehicle can be obtained even if the equalization process is performed, and the equalization process is not stopped.

FIG. 5 is a diagram illustrating the equalization process. The horizontal axis of the figure represents the cell groups 112a and 112b, and the vertical axis represents the SOC. The white circles in the figure represent cells whose SOC has not reached the target value, and the black circles represent cells whose SOC has reached the target value.
In the example of FIG. 5, the control circuit 128 has a high SOC by using the equalization circuit 127 so that the battery voltage of the cell 111 matches the target values set for each of the cell groups 112a and 112b. Discharge the cell 111. The target SOC of the cell group 112a is A, and the target SOC of the cell group 112b is B. As shown in FIG. 5, among the cell cells 111 constituting the cell groups 112a and 112b, the SOC of the cell cells 111 to be discharged is lowered, and all the cell cells 111 constituting the cell cells groups 112a and 112b are reduced. Discharge ends when the SOC matches the target value. When the target SOCs set in all the cell groups 112a and 112b are equalized according to the lowest target SOC, for example, B in the case of FIG. 5, all the assembled batteries 110 are configured. The SOC of the cell 111 can be matched to B.

FIG. 6 is a flowchart showing a second operation of the equalization estimation process of the equalization estimation unit 150a in the assembled battery control unit 150.
Generally, in a state where the ignition key of the vehicle is on, that is, in a state where charging / discharging is performed, the SOC of the cell 111 changes, so that it is generally difficult to estimate the SOC of the cell 111. ..

The equalization estimation process shown in FIG. 6 simulates whether the cell 111 should be equalized prior to the execution of the equalization process. For example, the ignition key of the vehicle is off, that is, the assembled battery. It is carried out during the period when charging and discharging are not performed. During this period, it is performed at predetermined time intervals or at any time when the equalization process is requested to be performed.
In FIG. 6, the same processing as the equalization estimation processing shown in FIG. 4 is designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 6, since the equalization estimation process is performed during the period when charging / discharging is not performed, the SOC estimated change amount ΔSOCaux (i) of the cell 111 is zero. Therefore, the equalization estimation process shown in FIG. 6 is a flowchart in which step 102 of the equalization estimation process shown in FIG. 4 is removed.

Further, step 104 is given by the equation (6).
SOCafter (i) = SOCbefore (i) + ΔSOCbal (i) ・ ・ ・ (6)
Other processing is the same as the equalization estimation processing shown in FIG.

Further, after performing the equalization estimation process shown in FIG. 6, the process shifts to the process of the equalization processing unit 150b in the assembled battery control unit 150, and the equalization processing unit 150b does not perform the equalization processing. Is stored in the storage unit 500, the equalization process is not performed. As a result, it is possible to determine that the average SOC value is lower than the threshold value after the equalization estimation process before actually performing the equalization process, and prevent the SOC of the cell 111 from being lowered due to the equalization process. ..

As described above, the SOC of the cell 111 can be easily estimated during the period when charging / discharging is not performed, and the accuracy of the estimation is improved. As a result, the stop of the equalization process can be correctly determined.

Next, the implementation time of the equalization process will be described.
The time required for one equalization process is basically a fixed value. However, the state of the battery changes depending on the variation in characteristics, environmental conditions, deterioration conditions, and the like. For example, even if the same equalization process is performed, if the progress of the equalization process is fast, specifically look at the SOC history, and if the degree of decrease in SOC gradually increases, the battery self It is possible that the discharge is large or the capacity is deteriorated and reduced. In this case, the time for performing the equalization process once is set short.

A specific example will be described below. First, every time the equalization process is performed, the SOC is recorded in the storage unit 500. Then, the SOC recorded in the storage unit 500 is read out before the equalization process is performed. Next, the difference between the SOCs read out for the past two times is taken and used as the SOC change amount ΔSOC. FIG. 7 shows a correspondence table between the SOC change amount prepared in advance and the equalization processing time stored in the storage unit 500. With reference to the correspondence table shown in FIG. 7, a new equalization processing time is determined from the amount of SOC change.

As described above, since the execution time of the equalization process is set based on the history of the charging state of the assembled battery, it is possible to prevent the SOC from being excessively lowered as compared with the case where the execution time is not changed, and the next vehicle. It is possible to prevent an event in which the required power cannot be obtained at startup.

Contrary to the above, when the progress of the equalization process is slow, the SOC history is referred to, and when the degree of decrease in the SOC is smaller than expected, one execution time of the equalization process is set. Set longer. By doing so, the equalization process can be performed more efficiently than when the execution time is not changed, so that the number of equalization estimation processes can be reduced. For example, the number of times the battery control device 100 is started while the vehicle is stopped. It can contribute to the reduction of electricity consumption and the processing load by reducing the amount of electricity.

The battery control device 100 performs a process of diagnosing whether or not the variation in the charging state of the plurality of cell cells 111 is equal to or greater than a predetermined value (hereinafter, referred to as imbalance diagnosis) when the battery control device 100 is activated. .. Imbalance diagnosis performs the following processes 1 to 3. 1. When the battery control device 100 is started, the SOC of each cell 111 is read from the starting voltage (OCV). 2. Find the maximum and minimum SOC of each cell 111. 3. When the difference between the maximum value and the minimum value is equal to or greater than the threshold value (for example, SOC difference> 20%), it is determined to be abnormal as a result of imbalance diagnosis.

However, if the implementation of the equalization process is prohibited as a result of the equalization estimation process according to the present embodiment, the equalization process may be insufficient and an imbalance diagnosis may occur at the next startup of the battery control device 100.

If the imbalance diagnosis is confirmed, the vehicle may not be able to start depending on the settings. If the vehicle is to be operated as much as possible, the result of the equalization estimation process according to the present embodiment should be prioritized over the imbalance diagnosis. Therefore, when the storage unit 500 stores that the equalization process was not performed when the battery control device 100 is started, whether or not the variation in the charging state of the plurality of single batteries 111 is equal to or more than a predetermined value. The process of diagnosing (imbalance diagnosis) is not performed, or the diagnosis result is invalidated.

A specific example will be described below with reference to FIG. FIG. 8 is a flowchart showing the determination process of the imbalance diagnosis in the assembled battery control unit 150, which is started when the battery control device 100 is started. In step 200 of FIG. 8, the stored information regarding the execution of the equalization process stored in the storage unit 500 in step 109 of FIG. 4 or FIG. 6 is read out. In step 201 of FIG. 8, the implementation status of the equalization process is determined. If the equalization process has not been performed, the process proceeds to step 202 and the imbalance diagnosis is not performed. On the other hand, if the equalization process has been performed, the process proceeds to step 203 and the imbalance diagnosis is performed.

In this way, it is possible to avoid a situation in which the imbalance diagnosis is confirmed and the vehicle cannot travel, or an imbalance diagnosis in the case where it is clear that the abnormality is not determined. In this example, the battery control device 100 has been described as an example when it is started, but it is not limited to the time when the battery control device 100 is started, and it may be a predetermined operation when imbalance diagnosis is required.

In each of the above descriptions, the SOC of the cell 111 has been described as an example, but the SOC is not limited to the SOC, and the state of the battery 111 may be charged. The charging state of the cell 111 is any of the charging rate, the remaining capacity, and the voltage, in addition to the SOC of the cell 111.

Further, the programs shown in the flowcharts of FIGS. 4, 6 and 8 can be executed by a computer equipped with a CPU, a memory and the like. All processing or some processing may be realized by a hard logic circuit. Further, this program can be provided by being stored in a storage medium such as the assembled battery control unit 150 in advance. Alternatively, the program can be stored and provided in an independent storage medium, or the program can be recorded and stored in a storage medium such as the assembled battery control unit 150 via a network line. It may be supplied as a computer-readable computer program product in various forms such as a data signal (carrier wave).

According to the embodiment described above, the following effects can be obtained.
(1) A plurality of battery control devices 100 include an assembled battery 110 in which a plurality of cell cells 111 are connected in series, an equalization processing unit 150b that performs an equalization process for equalizing the charging states of the plurality of cell cells 111, and a plurality of batteries. Equalization estimation unit 150a for calculating an estimated value of the charging state when a plurality of cell cells 111 are equalized based on the charging state of the cell 111, and equalization by the equalization processing unit 150b. If the estimated value calculated by the equalization estimation unit 150a is less than a predetermined value before the equalization processing is performed, the equalization processing unit 150b does not perform the equalization processing. As a result, the equalization process can be suppressed and the state of charge of the cell can be prevented from deteriorating.

The present invention is not limited to the above-described embodiment, and other embodiments considered within the scope of the technical idea of the present invention are also included within the scope of the present invention as long as the features of the present invention are not impaired. ..

100 Battery control device 110 Set battery 111 Single battery 112a, 112b Single battery group 120 Single battery management unit 121a, 121b Single battery control unit 122 Bypass resistance 123 Bypass switch 124 Voltage detection circuit 125 SW drive circuit 127 Equalization circuit 128 Control circuit 130 Current detection unit 140 Voltage detection unit 150 Battery control unit 150a Equalization estimation unit 150b Equalization processing unit 160 Signal communication means 170 Insulation element 200 Vehicle control unit 300, 310 Relay 400 Inverter 500 Storage unit

Claims (8)

An assembled battery in which multiple batteries are connected in series,
An equalization processing unit that performs an equalization processing that equalizes the charging states of the plurality of cells.
It is provided with an equalization estimation unit that calculates an estimated value of the charging state when the plurality of cells are equalized based on the charging states of the plurality of cells.
A battery control device that does not perform the equalization processing by the equalization processing unit if the estimated value calculated by the equalization estimation unit is less than a predetermined value before the equalization processing is performed by the equalization processing unit. In the battery control device according to claim 1,
The equalization estimation unit calculates an estimated decrease in the charged state of each of the plurality of cells when the equalization process is performed, and calculates the estimated value based on the calculated estimated decrease. Battery control device to calculate. In the battery control device according to claim 2.
The equalization estimation unit calculates an estimated change amount of the charging state of the plurality of cells based on the current consumption flowing through the plurality of cells, and based on the calculated estimated change amount and the estimated decrease amount. A battery control device that calculates the estimated value. In the battery control device according to any one of claims 1 to 3.
A battery control device that performs the equalization processing by the equalization processing unit during a period in which the assembled battery is not charged or discharged. In the battery control device according to any one of claims 1 to 3.
The equalization processing unit performs the equalization processing for equalizing the charging states of the plurality of cells for a predetermined time.
The battery control device that sets the predetermined time based on the history of the charging state of the assembled battery. In the battery control device according to any one of claims 1 to 3.
A storage unit for storing whether or not the equalization process has been performed is provided.
When the storage unit stores that the equalization process was not performed during the predetermined operation of the battery control device, it is determined whether or not the variation in the charging state of the plurality of single batteries is equal to or greater than the predetermined value. A battery control device that does not perform a diagnostic process or invalidates the diagnostic result of the diagnostic process. In the battery control device according to claim 6,
The battery control device is the time when the battery control device is activated during the predetermined operation. In the battery control device according to any one of claims 1 to 3.
The charging state is a battery control device having any one of the SOC, charging rate, remaining capacity, and voltage of the cell.

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