JP2003243044A - Voltage detecting device for package battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a voltage detecting device for a package battery capable of detecting the voltage for controlling the package battery using a terminal voltage of each unit cell even in the case the total voltage of the package battery is not detected. <P>SOLUTION: A battery controller B/C controls the charge/discharge power of the package battery using the total voltage value Va'(load) detected by a voltage detector 201 and subjected to a thermal correction and a sum Vb(load) of unit cell voltage values detected by respective cell controllers C/Cn. The procedures are such that (1) when |Va'(load)-Vb(load)| is below the specified value Z, the control is conducted using the total voltage value Va'(load) and the amperage detected by a current detector 202, (2) when |Va'(load)-Vb(load)| exceeds the value Z and the cell controller C/Cn side is in failure, the control is conducted using the total voltage value Va'(load) and the amperage given by the current detector 202, and (3) when |Va'(load)-Vb(load)| exceeds the value Z and the voltage detector 201 is in failure, the control is conducted using Vb(load)+V and the amperage given by the current detector 202. In above, V represents the voltage detecting error in no-load operation between the voltage detector 201 and cell controller C/Cn. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembled battery voltage detecting device.

[0002]

2. Description of the Related Art As a battery for driving an electric vehicle, an assembled battery composed of a plurality of single cells is known. An apparatus for controlling the charge / discharge power of such an assembled battery is disclosed in, for example, Japanese Patent Application Laid-Open No. 9-312939. According to this power control device, the terminal voltage of each single cell is detected by the cell controller of the battery pack, and the terminal voltage (total voltage) of the battery pack is detected by the voltage sensor.

[0003]

In the conventional power control device, the control value of the charge / discharge power is calculated using the total voltage, and the control value is corrected using the terminal voltage of the single cell. For this reason,
If the voltage sensor fails and the total voltage of the battery pack is not detected, the correct control value may not be calculated.

An object of the present invention is to provide an assembled battery voltage detecting device which detects the voltage of the assembled battery by the voltage of each unit battery (single cell) even when the terminal voltage of the assembled battery is not detected. It is in.

[0005]

(1) The invention according to claim 1 is applied to a voltage detecting device for an assembled battery composed of a plurality of unit batteries. And provided for each unit battery,
A unit voltage detection circuit that detects the voltage of a unit battery, a total voltage calculation circuit that calculates the sum of a plurality of unit battery voltages detected by the unit voltage detection circuit, and a total voltage detection circuit that detects the terminal voltage of the assembled battery , A diagnostic circuit that determines whether there is an abnormality in the total voltage detection circuit, and (1) when the diagnostic circuit determines that there is no abnormality, the terminal voltage is the detected voltage of the assembled battery, and (2) there is an abnormality in the diagnostic circuit. When it is determined, by including a control circuit that uses the total voltage as the detection voltage of the assembled battery,
The above-mentioned object is achieved. (2) The invention according to claim 2 is the assembled battery voltage detection device according to claim 1, further comprising a difference calculation circuit for calculating a difference between the terminal voltage and the total voltage when the assembled battery is unloaded. The control circuit corrects the total voltage by the difference when the diagnostic circuit determines that there is an abnormality. (3) The invention according to claim 3 is the voltage detecting device for an assembled battery according to claim 1 or 2, wherein a time matching between the detection result by the unit voltage detection circuit and the detection result by the total voltage detection circuit is performed. It is characterized by further comprising a timing control circuit. (4) The invention according to claim 4 is the assembled battery voltage detection device according to any one of claims 1 to 3, further comprising a temperature detection circuit for detecting the temperature of the total voltage detection circuit, and the control circuit is When the diagnostic circuit determines that there is no abnormality, the terminal voltage is corrected according to the temperature detected by the temperature detection circuit. (5) The invention according to claim 5 is applied to a voltage detecting device for an assembled battery including a plurality of unit batteries. Then, a unit voltage detection circuit provided for each unit battery, which detects the voltage of the unit battery, a total voltage calculation circuit which calculates the sum of a plurality of unit battery voltages detected by the unit voltage detection circuit, and a terminal of the assembled battery A total voltage detection circuit for detecting the voltage, a difference calculation circuit for calculating the difference between the terminal voltage and the total voltage when the battery pack is not loaded, and a detection result by the unit voltage detection circuit,
A timing control circuit that time-matches with the detection result by the total voltage detection circuit, a diagnostic circuit that determines whether there is an abnormality in the total voltage detection circuit, and (1) When the diagnostic circuit determines that there is no abnormality, the terminal The voltage is used as the detection voltage of the battery pack, and (2) when the diagnostic circuit determines that there is an abnormality, the total voltage of multiple unit battery voltages time-matched by the timing control circuit is corrected by the difference to correct the battery pack. The above-described object is achieved by including a control circuit that uses the detection voltage of. (6) The invention according to claim 6 is the voltage detecting device for an assembled battery according to claim 5, wherein the diagnostic circuit is such that the difference between the terminal voltage and the total voltage exceeds a first predetermined value, and the unit voltage When all of the plurality of unit battery voltages detected by the detection circuit are within the second predetermined value with respect to the average value of the plurality of unit battery voltages, it is determined that the total voltage detection circuit is abnormal.

[0006]

According to the present invention, the voltage of the assembled battery can be detected by using the voltage of each unit battery even if an abnormality occurs in the circuit for detecting the terminal voltage of the assembled battery.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In addition, in the following embodiments, an example in which the assembled battery is applied as a power source of an electric vehicle will be described.
FIG. 1 is an overall configuration diagram of an assembled battery for a vehicle according to an embodiment of the present invention. In FIG. 1, the assembled battery is composed of 40 cells C1 to C40 connected in series.
.About.C40 are grouped into eight groups to form five module batteries M1 to M5. The number of cells forming the assembled battery and each module battery is not limited to the number described in this description. Five module batteries M1 to M
5 are cell controllers C / C1 and C / C, respectively.
2, ..., C / C5 are connected. Each of the five cell controllers C / C1 to C / C5 has a CPU, a memory, and a timer, and manages eight cells forming the module battery Mn for each module battery. Here, n is an integer of 1 to 5. The power from the assembled battery is
It is supplied to the vehicle system that controls the vehicle. Here, the vehicle system includes an inverter, a motor, and the like for supplying electric power from the battery pack to drive the vehicle, and also includes a total voltage Va ′ (load) of the battery pack transmitted from the battery controller B / C or It includes a vehicle controller for displaying the capacity of the capacity meter and controlling the traveling of the vehicle by the total voltage Vb (load).

The cell controller C / Cn has a voltage detection circuit, which will be described later, and individually detects the voltages of the eight unit cells in each module battery Mn when the cell voltage is detected. A single cell voltage detection timing is controlled by a timer, and the single cell detection voltage is determined by each cell controller C / C.
stored in the memory within n. Cell controller C / Cn
Is the cell controller C / using the voltage detection value of the single cell.
The failure of the voltage detection circuit in Cn is diagnosed. In particular,
The average value Vave of the detected eight single cell voltage values is calculated,
When at least one of the eight unit cell voltage values has a difference of a predetermined voltage threshold value or more with the average value Vave, it is considered that an abnormality has occurred in the voltage detection circuit and abnormal data has occurred in the voltage detection value. . Such failure diagnosis is performed every time the voltage of a single cell is detected.

The cell controller C / Cn further outputs a signal for adjusting the capacity of each of the eight single cells that form each module battery Mn. The cell capacity adjustment will be described later. Electric power is supplied to the cell controller C / Cn from each module battery Mn. The CPU of each cell controller C / Cn has a built-in communication interface, and communicates with the battery controller B / C via this communication interface. The cell controllers C / C1 to C / C5 are managed by the battery controller B / C.

Cell controller C / C1 to C / C5 C
The PU turns on the power when the ON signal is transmitted from the battery controller B / C, and turns off the power when the OFF signal is transmitted.

The battery controller B / C is a CPU 2
04, a memory 205, and a timer 206.
The CPU 204 of the battery controller B / C has a built-in communication interface and communicates with each cell controller C / Cn. By this communication, the battery controller B / C causes the cell controllers C / C1 to C / C5 to
While controlling each cell controller C / C1 to C / C
5, battery information and diagnostic information are received.

The battery information is the voltage value of a single cell in each module battery Mn detected by the voltage detection circuit of each cell controller C / C1 to C / C5 when the cell voltage is detected. The battery information received by the battery controller B / C is stored in the memory 205 in the battery controller B / C, is used for controlling the cell controllers C / C1 to C / C5, and displays the capacity of a capacity meter (not shown). Used for etc. Overcharge occurs when the voltage value of the single cell is higher than a predetermined voltage range, and overdischarge occurs when the voltage value of the single cell is lower than the predetermined voltage range. In this way, the charge state can be known from the voltage value of the single cell.

The diagnostic information is the cell controller C / C1.
This is abnormal data when an abnormality is detected in the voltage detection result in C / C5. Battery controller B / C
The diagnostic information received by the battery controller is the battery controller B / C.
Stored in the memory 205 of the battery controller B
/ C is used for failure diagnosis.

The battery controller B / C is provided for each of the five cell controllers C / C1 to C / C5.
It outputs a signal instructing the voltage detection of all the unit cells that make up each module battery Mn, or a signal instructing the capacity adjustment of each unit cell. The battery controller B / C further calculates the battery capacity and the battery deterioration state for displaying the capacity of a capacity meter (not shown), and manages the vehicle with signals such as the calculated battery capacity and the battery deterioration state. Output to a controller or the like (not shown). In addition, the battery controller B / C
When the abnormal data is received from any of the cell controllers C / C1 to C / C5, the indicator ID is lit to indicate that the abnormality has occurred.

The power of the battery controller B / C is supplied from the auxiliary battery B. Battery controller B / C
Is turned on / off in conjunction with an ignition switch (not shown) of the vehicle.

The voltage sensor 201 detects the total voltage of the assembled battery and outputs a detection signal to the battery controller B / C. The total voltage is a voltage detected by connecting the five module batteries M1 to M5 forming the assembled battery in series. The detection timing of the total voltage is controlled by the timer 206 of the battery controller B / C, and the detected total voltage value is stored in the memory 205 in the battery controller B / C. The current sensor 202 detects a current flowing through the battery pack and outputs a detection signal to the battery controller B / C. The detected current value is stored in the memory 205 in the battery controller B / C. The temperature sensor 203 detects the temperature of the voltage sensor 201 and outputs a detection signal to the battery controller B / C. The detected temperature value is stored in the memory 205 in the battery controller B / C.

The battery controller B / C controls the charging / discharging power of the battery pack by performing a predetermined calculation process using the total voltage value detected by the voltage sensor 201 and the current value detected by the current sensor 202. To do.

FIG. 2 is a circuit block diagram in the cell controller C / C1. Here, the cell controller C / C
1 will be described as an example, but another cell controller C /
C2 to C / C5 are similar to the cell controller C / C1. In FIG. 2, the module battery M1 and the cell controller C / C1 are connected. Module battery M1
Is composed of eight cells C1 to C8 connected in series. The cell controller C / C1 includes a CPU, eight differential amplifiers D1 to D8, and eight capacitance adjusting circuits E1 to E8.
E8 and. The capacitance adjustment circuits E1 to E8 are provided with capacitance adjustment circuit switches SWb1 to SWb8 and resistors R1 to R8, respectively.

The eight differential amplifiers D1 to D8 respectively detect the terminal voltage Vc1 of the single cells C1 to C8 when the cell voltage is detected.
To Vc8 are individually detected, and detection voltages Vd1 to Vd8 are output. The CPU has a built-in A / D conversion circuit (not shown) and converts the detection voltages Vd1 to Vd8 output from the differential amplifiers D1 to D8 into digital values, respectively. CP
U is a cell C based on the digitally converted voltage data.
Management of 1 to C8 and failure diagnosis of the voltage detection circuit are performed. Here, the voltage detection circuit is composed of the differential amplifiers D1 to D8. The CPU transmits the battery information of the single cells C1 to C8 and the diagnostic information of the differential amplifiers D1 to D8 to the battery controller B / C by serial communication. The transmission terminal is Tx and the reception terminal is Rx.

The capacity adjusting circuits E1 to E8 are single cells C1 to C.
8 is discharged respectively. Capacity adjustment circuit switch SWb
1 to SWb8 are turned on by an on signal sent from the CPU and turned off by an off signal. When the capacitance adjustment circuit switches SWb1 to SWb8 are turned on, the single cells C1 to C8 are discharged via the corresponding resistors R1 to R8. The CPU determines the capacity variation of the unit cell (specifically, a voltage higher than the average value of the unit cell voltages of C1 to C8) from the above voltage detection data, and sets the capacity adjustment circuit switch corresponding to this cell to the cell. Turn on to discharge.

The battery controller B / C controls each of the cell controllers C / C1 to C / C5 based on the information transmitted from the cell controllers C / C1 to C / C5 by serial communication as described above. . In the normal control performed while the vehicle is traveling or the battery is being charged, charge / discharge control of the assembled battery is performed based on the total voltage detected by the voltage sensor 201, and the cell controllers C / C1 to C / C5.
Depending on the battery information transmitted from the cell controller C /
Instruct C1 to C / C5 to adjust the capacity of the single cell. When abnormal data is sent from the cell controllers C / C1 to C / C5 to the battery controller B / C, the indicator ID
To notify the driver of the abnormality and to perform fail-safe operation (input / output restriction, etc.).

According to the present invention, when an abnormality occurs in the voltage sensor 201, the total voltage is calculated using the voltage detection value of the single cell detected by the cell controller C / Cn, and the calculated total voltage value and current sensor. It is characterized in that the charge / discharge power of the battery pack is controlled using the current value detected by 202.

The processing performed by the above battery controller B / C will be described. FIG. 3 is a flowchart illustrating the flow of processing executed by the CPU 204 of the battery controller B / C. The process according to FIG. 3 is activated in conjunction with turning on the ignition switch of the vehicle. In step S11 of FIG. 3, power is supplied from the auxiliary battery B to the CPU 204, the CPU 204 is activated, and the process proceeds to step S12. In step S12, the CPU 20
In step 4, the initial diagnosis process is performed and the process proceeds to step S13. The initial diagnosis process is a process for diagnosing the battery under no load. Details of the initial diagnosis processing will be described later.

In step S13, the CPU 204 performs a normal diagnosis process. The normal diagnosis process is a battery diagnosis process performed while the vehicle is traveling. Details of the normal diagnosis process will be described later. When the normal diagnosis process is completed, the CPU 204 ends the process shown in FIG. Note that the process shown in FIG. 3 ends when the ignition switch is turned off even during a subroutine process described later.

FIG. 4 is a flow chart for explaining the initial diagnosis processing subroutine. In step S21 of FIG. 4, the CPU 204 sets the value of the abnormality determination flag A to the initial value 0, and proceeds to step S22. The abnormality determination flag A is a flag that is set to 1 when the voltage sensor 201 is abnormal, 2 when the voltage detection circuit of the cell controller C / Cn is abnormal, and 0 when both are normal.

In step S22, the CPU 204
Is the total voltage value Va detected by the voltage sensor 201.
Is stored in the memory 205 in the battery controller B / C, and the process proceeds to step S23. In step S23,
The CPU 204 has five cell controllers C / C1 to C
/ C5 is instructed to detect the voltage of all the unit cells that form each module battery Mn. This allows
The cell controllers C / C1 to C / C5 detect the voltage of each single cell. The CPU 204 has a total of 40 transmitted from the cell controllers C / C1 to C / C5.
The total sum of the voltage detection values of the single unit cells is calculated, and the calculated total sum voltage value Vb is used as the memory 2 in the battery controller B / C.
It is stored in 05 and proceeds to step S24.

In step S24, the CPU 204
Determines whether the difference between the total voltage value Va and the total voltage value Vb is less than or equal to a predetermined value Y. The CPU 204 uses | Va-Vb |
When ≦ Y is satisfied, the affirmative decision is made in step S24 and the operation proceeds to step S25, and when | Va−Vb | ≦ Y is not met, a negative decision is made in step S24 and the operation proceeds to step S26. The process proceeds to step S25 when it is considered normal, and the process proceeds to step S26 when it is considered abnormal.

In step S25, the CPU 204
Is the absolute value of the difference between the total voltage value Va and the total voltage value Vb V =
| Va-Vb | is stored in the memory 205 in the battery controller B / C, and the process shown in FIG. 4 ends. The value of the difference V is determined by the voltage sensor 201 and the cell controller C / C.
This corresponds to a detection error between the voltage detection circuits 1 to C / C5.
On the other hand, in step S26, the CPU 204 performs a fail safe (F / S) process and ends the process shown in FIG.

FIG. 5 is a flow chart for explaining the details of the fail-safe processing subroutine. Step S
At 31, the CPU 204 causes the cell controller C /
It is determined whether or not there is a failure in the voltage detection circuit of C1 to C / C5. The CPU 204 is a cell controller C / C1 to
The C / C5 is requested to transmit the diagnostic information, and the diagnostic information transmitted from the cell controllers C / C1 to C / C5 is stored in the memory 205. The CPU 204 has a memory 20.
When abnormal data is stored in the diagnostic information of No. 5, it is considered that a failure has occurred in the voltage detection circuits of the cell controllers C / C1 to C / C5, the affirmative decision is made in step S31, and the operation proceeds to step S34. On the other hand, the CPU 204 makes a negative determination in step S31 if abnormal data is not stored in the diagnostic information, and proceeds to step S32.

In step S32, the CPU 204
Considers that the voltage sensor 201 has failed, and proceeds to step S33. In step S33, the CPU2
04 sets the value of the abnormality determination flag A to 1 and proceeds to step S35. In step S34, the CPU 20
4 sets the value of the abnormality determination flag A to 2 and proceeds to step S35. In step S35, the CPU 204
Outputs a warning display lighting request to the indicator ID, and ends the processing in FIG. As a result, the driver is notified of the abnormality.

FIG. 6 is a flow chart for explaining the subroutine of the normal diagnosis processing. In step S41 of FIG. 6, the CPU 204 determines whether normality is determined in the initial diagnosis process. The CPU 204 makes an affirmative decision in step S41 if the abnormality judgment flag A = 0 to proceed to step S42, and if A ≠ 0, carries out step S41.
A negative determination of 41 is made and the operation proceeds to step S48.

In step S42, the CPU 204
Causes the timer 206 to start clocking, and determines whether the clocked time T is a predetermined time Tn. The predetermined time Tn is a battery diagnosis (voltage check) interval in the normal diagnosis. C
When the time count T = Tn is satisfied, the PU 204 makes an affirmative decision in step S42 and proceeds to step S43 where T = Tn.
If is not established, the negative determination is made in step S42 and the clocking is continued.

In step S43, the CPU 204
Is the total voltage value Va detected by the voltage sensor 201.
(load) to the memory 205 in the battery controller B / C
Then, the process proceeds to step S44. In step S44, the CPU 204 corrects the total voltage value Va (load) according to the temperature detected by the temperature sensor 203, stores the temperature-corrected total voltage value Va ′ (load) in the memory 205, and then stores the corrected total voltage value Va ′ (load) in step S45. Go to.

FIG. 7 is a diagram showing the temperature correction coefficient of the voltage sensor 201. In FIG. 7, the horizontal axis is the temperature and the vertical axis is the correction coefficient. Voltage sensor 2 according to the present embodiment
When 01 is expressed with 25 ° C. as a reference, 01 has temperature characteristics in which the voltage detection value becomes smaller on the higher temperature side than 25 ° C. and on the lower temperature side than 25 ° C. Therefore, with respect to the total voltage detection value Va (load) by the voltage sensor 201, the temperature sensor 203
25 multiplied by the coefficient corresponding to the temperature value detected by
A total voltage value Va ′ (load) in terms of ° C. is calculated. Note that FIG.
The temperature correction coefficient according to is stored in advance in a memory (not shown) in the CPU 204.

In step S45, the CPU 204
Instructs each of the five cell controllers C / C1 to C / C5 to detect the voltage of all the unit cells that form each module battery Mn. Each cell controller C / C
Instructions to n are sequentially performed by the above-described communication. As a result, the cell controllers C / C1 to C / C5
Respectively detect the voltage of a single cell. CPU204
Calculates the sum total of the voltage detection values of 40 unit cells in total transmitted from the cell controllers C / C1 to C / C5, stores the calculated total voltage value Vb (load) in the memory 205, and proceeds to step S46. move on.

Here, the timing of voltage detection will be described. FIG. 8 shows five cell controllers C / C1 to C
6 is a diagram illustrating a timing at which voltage detection is performed by / C5 and a voltage sensor 201. FIG. Each cell controller C / Cn is configured to store the single cell voltage detected during the predetermined time Δt in the memory in the cell controller C / C. At the timing t1 in FIG. 8, the cell controller C / C1 receives a command from the CPU 204 in the battery controller B / C,
The unit cell voltage is detected for a time Δt and the detected value is stored in the memory.

At the timing t2, the cell controller C / C2 is C in the battery controller B / C.
Receives a command from the PU 204 and sets the unit cell voltage to the time Δt.
During this period, the detected value is stored in the memory. Similarly after that,
From timing t3, timing t4, and timing t5, the cell controller C / C3, the cell controller C
/ C4 and the cell controller C / C5 detect the single cell voltage during the time Δt and store the detected value in the memory.

At timing t6, the CPU2
04 outputs a command to the voltage sensor 201 to detect the total voltage under load. CPU 204 is a cell controller C
/ C1 to C / C5 when transmitting the voltage detection value of a single cell, the voltage detection value corresponding to the timing t6 among the voltage detection values stored in the memory in each cell controller C / Cn is transmitted. To the CPU of each cell controller C / Cn. As a result, the single cell voltage detection timing and the total voltage detection timing match. The timing at which the current sensor 202 detects the current is also controlled to match the timing t6.

In step S46, the CPU 204
Is the total voltage value Va ′ (load) after temperature correction and the total voltage value V
It is determined whether the difference from b (load) is less than or equal to a predetermined value Z. CP
The U204 makes an affirmative decision in step S46 if | Va ′ (load) −Vb (load) | ≦ Z is true, and then in step S4.
Returning to step 2, if | Va ′ (load) −Vb (load) | ≦ Z is not satisfied, a negative determination is made in step S46 and step S4.
Proceed to 7. The case of returning to step S42 is a case where it is regarded as normal, and the above-described voltage detection of the single cell and detection of the total voltage are repeated every predetermined time Tn. In this case,
The charge / discharge power of the battery pack is controlled using the temperature-corrected total voltage value Va ′ (load) detected by the voltage sensor 201 and the current value detected by the current sensor 202.

In step S48 to which the operation proceeds after making a negative decision in step S41 described above, the CPU 204 determines whether or not the abnormality determination flag A = 1. When the abnormality determination flag A = 1 (a failure has occurred in the voltage sensor 201), the CPU 204 makes an affirmative decision in step S48 and proceeds to step S48A where A = 2 (in the voltage detection circuit of the cell controllers C / C1 to C / C5). If a failure occurs), a negative determination is made in step S48 and the determination processing is repeated. When A = 2, the determination process is repeated, but this is to prevent the faulty voltage detection circuit from detecting the single cell voltage. In this case, the voltage sensor 201 detects the total voltage value Va (load), and the charge / discharge power of the battery pack is controlled using the total voltage value Va (load) and the current value detected by the current sensor 202. To be done.

In step S48A, the CPU 204
Instructs each of the five cell controllers C / C1 to C / C5 to detect the voltage of all the unit cells that form each module battery Mn. As a result, the cell controllers C / C1 to C / C5 detect the voltage of each single cell. The CPU 204 is a cell controller C / C1 to
The total sum of the voltage detection values of the 40 single cells transmitted from C / C5 is calculated, the calculated total sum voltage value Vb (load) is stored in the memory 205, and the process proceeds to step S49.

In step S49, the CPU 204
Calculates Va (load) = Vb (load) + V and calculates step S
Return to 48A. However, V is a difference between the no-load total voltage value Va and the no-load total voltage value Vb stored in the memory 205 by the initial diagnosis process. Accordingly, when an abnormality occurs in the voltage sensor 201, the total voltage value Va (load) is calculated using the voltage detection value of the single cell detected by the cell controller C / Cn, and the calculated total voltage value Va ( loa
The charge / discharge power of the battery pack is controlled using d) and the current value detected by the current sensor 202.

In step S47 to which the operation proceeds after making a negative decision in step S46 described above, the CPU 204 performs a fail-safe (F / S) process and returns to step S42.
FIG. 9 is a flowchart illustrating the details of the fail-safe processing subroutine. In step S51, the CPU 204 causes the cell controllers C / C1 to C /
It is determined whether or not the voltage detection circuit of C5 has a failure. C
The PU 204 requests the cell controllers C / C1 to C / C5 to transmit diagnostic information, and the cell controllers C / C1 to
The diagnostic information transmitted from C / C5 is stored in the memory 205. The CPU 204 determines the cell controller C when abnormal data is stored in the diagnostic information of the memory 205.
It is considered that a failure has occurred in the voltage detection circuits / C1 to C / C5, the affirmative decision is made in step S51, and the operation proceeds to step S53. In this case, the charge / discharge power of the battery pack is controlled using the temperature-compensated total voltage value Va ′ (load) detected by the voltage sensor 201 and the current value detected by the current sensor 202. .

On the other hand, the CPU 204 determines that a failure has occurred in the voltage sensor 201 when abnormal data is not stored in the diagnostic information, makes a negative determination in step S51, and proceeds to step S52. In step S52, C
The PU 204 calculates Va (load) = Vb (load) + V and proceeds to step S53. However, V is a difference between the no-load total voltage value Va and the no-load total voltage value Vb stored in the memory 205 by the initial diagnosis process. Accordingly, when an abnormality occurs in the voltage sensor 201, the total voltage value Va (load) is calculated using the voltage detection value of the single cell detected by the cell controller C / Cn, and the calculated total voltage value Va ( load) and the current value detected by the current sensor 202, the charge / discharge power of the battery pack is controlled.

In step S53, the CPU 204
Outputs a warning display lighting request to the indicator ID, and ends the processing in FIG. As a result, the driver is notified of the abnormality.

The embodiments described above will be summarized. (1) The battery controller B / C performs an initial diagnosis process of the assembled battery in a no-load state, and the terminal voltage of the assembled battery, that is, the total voltage value Va and the 40 unit cell voltages that form the module batteries M1 to M5 And the difference V = | Va−Vb | between the two is calculated and stored in the memory 205. As a result, the detection error between the voltage sensor 201 that detects the total voltage Va and the voltage detection circuit of each cell controller C / Cn can be known. (2) When the detection error V exceeds the predetermined value Y, it is considered as an abnormality and the fail-safe process (FIG. 5) is performed, so that the driver can be notified of the abnormality occurrence. (3) At the time of detecting eight single cell voltages in each cell controller C / Cn, an average value Vave of the detected eight single cell voltage values is calculated, and at least one of the eight single cell voltage values is between the average value Vave. When there is a difference equal to or larger than the predetermined voltage threshold, the voltage detection circuit on the cell controller C / Cn side is considered to be abnormal. As a result, when the detection error V exceeds the predetermined value Y, the voltage sensor 2
It is possible to discriminate between the 01-side abnormality and the cell controller C / Cn-side abnormality. When the cause of the failure is isolated, it becomes possible to take action according to the cause of the failure when the failure occurs. (4) The battery controller B / C performs normal diagnosis processing of the assembled battery during normal operation such as when the vehicle is running, and the terminal voltage of the assembled battery, that is, the total voltage value Va (load) and the module battery M
Total voltage value V of 40 unit cell voltages constituting 1 to M5
Find b (load). The temperature of the voltage sensor 201 is detected by the temperature sensor 203, and the total voltage value V after the temperature correction is performed.
A '(load) is calculated and it is determined whether or not | Va' (load) -Vb (load) | is equal to or less than a predetermined value Z. Since the total voltage value can be corrected by compensating the temperature characteristic of the voltage sensor 201, the detection accuracy of the total voltage can be increased. (5) The battery controller B / C controls charge / discharge power of the assembled battery as follows. When | Va ′ (load) −Vb (load) | is less than or equal to the predetermined value Z, the temperature-corrected total voltage value Va ′ (load) and the current sensor 2
The charge / discharge power of the battery pack is controlled using the current value detected by 02. | Va '(load) -Vb (load) | exceeds the predetermined value Z and the voltage detection circuit on the cell controller C / Cn side is abnormal (affirmative determination in step S51), the total voltage value after temperature correction The charge / discharge power of the battery pack is controlled using Va ′ (load) and the current value detected by the current sensor 202. When | Va '(load) -Vb (load) | exceeds the predetermined value Z and the voltage sensor 201 is abnormal (negative determination in step S51), voltage detection of the single cell detected by the cell controller C / Cn Total voltage value Va (load) = Vb
(load) + V is calculated, and the charge / discharge power of the battery pack is controlled using the calculated total voltage value Va (load) and the current value detected by the current sensor 202. When the abnormality of the voltage detection circuit on the cell controller C / Cn side is determined in the initial diagnosis processing (negative determination in step S48), the total voltage value Va (load) by the voltage sensor 201.
And the current value detected by the current sensor 202 are used to control the charge / discharge power of the assembled battery. When the abnormality of the voltage sensor 201 is determined in the initial diagnosis process (Yes in step S48), the total voltage value Va (load) = Vb is calculated using the voltage detection value of the single cell detected by the cell controller C / Cn. (load) + V is calculated, and the charge / discharge power of the battery pack is controlled using the calculated total voltage value Va (load) and the current value detected by the current sensor 202. As above and as above, the battery controller B / C
The CPU 204 can control the charging / discharging power of the battery pack using the total voltage Vb (load) even when an abnormality occurs in the voltage sensor 201. At this time, the total voltage Va
Since the correction is performed by the detection error V between the voltage sensor 201 and the voltage detection circuit of each cell controller C / Cn in the calculation of, It does not change significantly before and after the occurrence of an abnormality in the voltage sensor 201. Further, the capacitance display of the capacitance meter (not shown) does not change significantly before and after the occurrence of the abnormality of the voltage sensor 201. (6) Single cell voltage detection timing by the voltage detection circuit of each cell controller C / Cn, and the voltage sensor 201
Since the detection timing of the total voltage by the voltage sensor 201 and the cell controller C / C are matched.
It is possible to suppress the detection error V from the n-th voltage detection circuit. In particular, in a vehicle in which the frequency of current fluctuations is high, there is a high possibility that the voltage value detected will differ depending on the timing of voltage detection. Match the voltage detection timing to detect the error V
By suppressing the above, similarly to the above (5), the control value of the charging / discharging power does not change significantly before and after the occurrence of the abnormality of the voltage sensor 201.

In the above description, each cell controller C
/ Cn is configured to store the single cell voltage detected during the predetermined time Δt in the memory in the cell controller C / Cn, respectively, and to detect the voltage detection value stored in the memory in each cell controller C / Cn. Among them, by transmitting the voltage detection value corresponding to the timing t6 that coincides with the detection timing by the voltage sensor 201 to the battery controller B / C, the time between the voltage sensor 201 and the voltage detection circuit of each cell controller C / Cn I tried to make a physical match. Instead of this, each cell controller C / C
It is also possible to time-match between the voltage sensor 201 and the voltage detection circuits of the cell controllers C / Cn by simultaneously detecting the single cell voltage at timing t6 for each n.

In the above description, an electric vehicle has been described as an example, but the present invention can be applied to any hybrid vehicle (HEV) equipped with an engine and a motor as long as it has an assembled battery.

Correspondence between each component in the claims and each component in the embodiment of the invention will be described. The unit batteries correspond to cells C1 to C40, for example. The unit voltage detection circuit is, for example, a differential amplifier D.
1 to D8. The total voltage calculation circuit, the diagnostic circuit, the control circuit, and the difference calculation circuit are, for example, the CPU 2
04. The terminal voltage corresponds to the total voltage. The total voltage detection circuit is composed of, for example, the voltage sensor 201. The timing control circuit is, for example,
CPU 204, timer 206, cell controller C /
It is composed of C1 to C / C5 CPUs, memories and timers. The temperature detection circuit is composed of, for example, the temperature sensor 203. The first predetermined value corresponds to a predetermined value Z (predetermined value Y), for example. A predetermined voltage threshold corresponds to the second predetermined value. In addition,
Each component is not limited to the above configuration unless the characteristic function of the present invention is impaired.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an assembled battery for a vehicle according to an embodiment of the present invention.

FIG. 2 is a circuit block diagram in a cell controller.

FIG. 3 is a flowchart illustrating a flow of processing executed by a CPU of a battery controller.

FIG. 4 is a flowchart illustrating a subroutine of initial diagnosis processing.

FIG. 5 is a flowchart illustrating a subroutine of fail-safe processing.

FIG. 6 is a flowchart illustrating a subroutine of normal diagnosis processing.

FIG. 7 is a diagram showing a temperature correction coefficient of a voltage sensor.

FIG. 8 is a diagram illustrating a timing at which voltage detection is performed by a cell controller and a voltage sensor.

FIG. 9 is a flowchart illustrating a subroutine of fail-safe processing.

[Explanation of symbols]

201 ... Voltage sensor, 202 ... Current sensor, 203 ... Temperature sensor, 204 ...
CPU, 205 ... Memory, 206
… Timer, B / C… Battery controller, C
1-C40 ... Cell, C / C1-C / C5 ... Cell controller, D1-D8 ... Differential amplifier, E1-E
8 ... Capacity adjustment circuit, ID ... Indicator,
M1 to M5 ... Module battery, SWb1 to SWb8
... Capacity adjustment circuit switch

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5G003 BA03 EA09 FA06 GC05                 5H030 AA00 AS06 AS08 DD08 FF22                       FF43 FF44                 5H115 PA08 PA14 PC06 PG04 PI14                       PI16 PI29 QN03 SE06 TI05                       TI06 TI10 TR06 TR19 TU04                       TW10 TZ01 TZ09 TZ14 UB01                       UB05 UB08 UB11

Claims (6)

[Claims] 1. An assembled battery voltage detection device comprising a plurality of unit batteries, wherein the unit voltage detection circuit is provided for each unit battery and detects the voltage of the unit battery, and the unit voltage detection circuit detects the unit voltage. A total voltage calculation circuit for calculating the total sum of the plurality of unit battery voltages, a total voltage detection circuit for detecting the terminal voltage of the assembled battery, and a diagnostic circuit for determining whether there is an abnormality in the total voltage detection circuit, 1) When it is determined that there is no abnormality in the diagnostic circuit, the terminal voltage is used as the detection voltage of the assembled battery, and (2) When it is determined that there is an abnormality in the diagnostic circuit, the total voltage is detected as the assembled battery. A voltage detecting device for an assembled battery, comprising: a control circuit for setting a voltage. 2. The assembled battery voltage detection device according to claim 1, further comprising a difference calculation circuit that calculates a difference between the terminal voltage and the total voltage when the assembled battery is unloaded. Is a voltage detecting device for an assembled battery, wherein the total voltage is corrected by the difference when the diagnosis circuit determines that there is an abnormality. 3. The assembled battery voltage detection device according to claim 1, further comprising a timing control circuit for time-matching the detection result of the unit voltage detection circuit and the detection result of the total voltage detection circuit. An assembled battery voltage detection device further comprising: 4. The assembled battery voltage detection device according to claim 1, further comprising a temperature detection circuit that detects the temperature of the total voltage detection circuit, wherein the control circuit is the diagnostic circuit. A voltage detecting device for an assembled battery, which corrects the terminal voltage according to the temperature detected by the temperature detecting circuit when it is determined that there is no abnormality. 5. A battery pack voltage detection device comprising a plurality of unit batteries, the unit voltage detection circuit being provided for each of the unit batteries for detecting the voltage of the unit battery, and detecting by the unit voltage detection circuit. A total voltage calculation circuit for calculating the total sum of the plurality of unit battery voltages, a total voltage detection circuit for detecting the terminal voltage of the assembled battery, and the terminal voltage and the total voltage when the assembled battery is unloaded. A difference calculation circuit that calculates a difference, a timing control circuit that temporally matches the detection result of the unit voltage detection circuit, and the detection result of the total voltage detection circuit, and determines whether there is an abnormality in the total voltage detection circuit And (1) when the diagnostic circuit determines that there is no abnormality, the terminal voltage is used as the detection voltage of the assembled battery, and (2) when the diagnostic circuit determines that there is abnormality, the A voltage detecting device for an assembled battery, comprising: a control circuit that corrects a total voltage of a plurality of unit battery voltages time-matched by an imming control circuit to obtain a detected voltage of the assembled battery. 6. The assembled battery voltage detecting device according to claim 5, wherein the diagnostic circuit is configured such that a difference between the terminal voltage and the total voltage exceeds a first predetermined value, and the unit voltage detecting circuit detects a difference between the terminal voltage and the total voltage. An assembled battery characterized in that when all of the detected plurality of unit battery voltages are within a second predetermined value with respect to the average value of the plurality of unit battery voltages, it is determined that the total voltage detection circuit is abnormal. Voltage detection device.