JP2000312443A - Module battery controller, module battery unit and module battery control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and uniformly charge and discharge a secondary battery constituting a module battery. SOLUTION: This module battery unit is composed of a battery voltage detector 2 for detecting each battery voltage of a plurality of secondary batteries B, a current sensor 8 (a shunt resistor) measuring and detecting the state of the charge and discharge of a module battery and a charging and discharging current detector 5, and capacity adjusting circuits 61-6n connected in parallel with each of the secondary batteries and adjusting the capacity of the secondary batteries, so that the voltage difference of each battery voltage is reduced on the basis of each battery voltage detected by the battery voltage detector 2 under the charging stop state or the discharging stop state detected by the charging and discharging current detector 5. The voltage difference of the secondary batteries at the charging and discharging stop period generated by the internal resistance of the secondary batteries and the difference of a charging current in the case of charging.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a module battery control device, a module battery unit and a module battery control method, and more particularly to a module battery control device for controlling a module battery in which a plurality of secondary batteries are connected in series, and the module. The present invention relates to a module battery unit having a battery control device and a module battery control method.

[0002]

2. Description of the Related Art For example, an electric vehicle uses a module battery (assembled battery) in which a plurality of secondary batteries (unit cells) are connected in series by an amount corresponding to a required capacity. Since such a module battery uses a large number of batteries, it is important to ensure reliability. That is, if any one of the secondary batteries constituting the module battery is overcharged or overdischarged, the function of the secondary battery is reduced and the function of the module battery as a whole is also reduced.

In particular, if the voltage of the secondary battery becomes too high during charging, safety is impaired. Therefore, a voltage higher than a predetermined value is prevented from being generated on the charger side. In addition, each secondary battery that constitutes a module battery has manufacturing variations, and when a secondary battery is used as a module battery, the charge acceptability and the discharge capacity vary due to uneven temperature distribution and the like. Come.

For this reason, the discharge capacity from a discharge depth of 0% (full charge) varies among the secondary batteries, and the discharge capacity as a module battery decreases. That is, at the time of discharging, the secondary battery having a reduced discharge capacity ends discharging quickly and enters an overdischarged state, and the overdischarged secondary battery becomes a load of another secondary battery and all secondary batteries are loaded. Before the depth of discharge of the next battery reaches 100%, the voltage drops, and the discharge ends as a module battery. Conversely, at the time of charging, the secondary battery which did not reach the depth of discharge of 100% at the time of discharging reaches the depth of discharge of 0% first and the voltage rises to terminate the charging. Since the charging ends without reaching the discharge depth of 0%, the difference in discharge capacity between the secondary batteries is widened. Therefore, when charging and discharging are repeated, the over-discharged secondary battery is always insufficiently charged, so that the variation increases and the discharge capacity of the entire module battery decreases.

[0005] In such a module battery in which a plurality of secondary batteries are connected in series, there is a variation between the respective secondary batteries, and there is a problem that the discharge capacity is reduced as a whole of the module battery and a specific secondary battery has a problem. In particular, there is a problem of deterioration, and heat may be generated by overcharging or overdischarging.

In order to cope with the above problem, a voltage detecting means is provided for each of the secondary batteries constituting the module battery, and the charging is terminated when the detected voltage reaches the charging end voltage. Further, a voltage detecting means and a bypass circuit for passing a charging current bypassing the secondary battery are provided in parallel for each of the secondary batteries constituting the module battery, and the secondary battery in which the detected voltage becomes the charging end voltage is provided. On the other hand, there is a configuration in which a charging current is bypassed in a bypass circuit of the secondary battery.

[0007]

However, in the former case of the above-mentioned conventional example, if there is a secondary battery which has reached the charge end voltage among a plurality of secondary batteries constituting the module battery, charging is stopped. Will no longer be
It is not possible to eliminate the variation in the battery voltage between the secondary batteries.

In the latter example, the charging current is bypassed only by the voltage of the secondary battery. However, in practice, each secondary battery has a variation in internal resistance. In a secondary battery having a small internal resistance but a large internal resistance, the terminal voltage increases depending on the internal resistance to reach the charge end voltage, and a high charge state cannot be obtained for a battery with a small internal resistance. This causes a variation in the state of charge of the secondary batteries having a large internal resistance, which hinders that the respective secondary batteries are uniformly and sufficiently charged, that is, that the entire module battery is fully charged.

[0009] As a method of charging a battery in which the variation occurs between the secondary batteries, a method of charging a secondary battery connected in series is known as a conventional example. According to this charging method, there is provided a means for examining the battery voltage of each secondary battery connected in series, and a bypass circuit for supplying a charging current bypassing the secondary battery is formed. No charging current flows to the secondary battery, and the other secondary battery is charged via the bypass circuit.

However, in the above-described method, the charging is stopped at each point when the charging stop voltage is reached, so that the charging stop time differs between the batteries connected in series. In addition, since a secondary battery having a high internal resistance reaches the charge stop voltage quickly, charging may be stopped quickly and the battery may not be fully charged.

The present invention focuses on the above problems, and allows a secondary battery constituting a module battery to be charged and discharged efficiently and evenly, and that the secondary battery can be reliably protected from overcharge or overdischarge. It is an object to provide a control device, a module battery unit, and a module battery control method.

[0012]

According to a first aspect of the present invention, there is provided a module battery control apparatus for controlling a module battery in which a plurality of secondary batteries are connected in series. Battery voltage detecting means for detecting a battery voltage of each of the plurality of secondary batteries, state detecting means for detecting a charge / discharge state of the module battery, and connected in parallel to each of the plurality of secondary batteries, In a state including at least one of a charge pause state and a discharge pause state among the charge / discharge states detected by the state detection means, the respective battery voltages are detected based on the respective battery voltages detected by the battery voltage detection means. And a capacity adjusting means for adjusting the capacity of the secondary battery so that the voltage difference of the secondary battery becomes small.

In a first aspect of the present invention, a battery voltage detecting means detects a battery voltage of each of the plurality of secondary batteries, and a state detecting means detects a charge / discharge state of the module battery. In a state including at least one of a charging pause state and a discharge pause state among the charging / discharging states detected by the state detecting unit by the capacity adjusting unit, based on each battery voltage detected by the battery voltage detecting unit. Thus, the capacity of the secondary battery is adjusted so that the voltage difference between the battery voltages is reduced. According to the first aspect of the present invention, a voltage difference (open-circuit voltage difference) between the plurality of secondary batteries during a charge / discharge pause caused by a difference in internal resistance and a charging current during charging caused by the plurality of secondary batteries. ) Is adjusted by the capacity adjusting means so that the battery voltages of the plurality of secondary batteries can be equalized.

In this case, when the voltage difference exceeds a preset value, a current corresponding to the capacity corresponding to the voltage difference is discharged, so that the charge capacity of the secondary battery is consumed. Can save money. Further, when each battery voltage detected by the battery voltage detecting means exceeds a preset set value, a shutoff means for shutting off charging and discharging of the module battery is further provided. When the voltage is abnormal, or when overcharging or overdischarging occurs, the charging / discharging can be interrupted by the interrupting means, thereby preventing the deterioration of each secondary battery, and thus, the discharge capacity of the entire module battery. The drop can be prevented.
Furthermore, at least one of module voltage detecting means for detecting a module voltage of the module battery and battery temperature detecting means for detecting a battery temperature of at least one of the plurality of secondary batteries is provided. The interrupting means may interrupt charging and discharging of the module battery when at least one of the module voltage and the battery temperature exceeds a preset value, respectively. When there is a problem or when the temperature of the secondary battery is abnormal, the charging and discharging can be performed safely without deteriorating the performance of each secondary battery and the module battery as a whole. Further, if the capacity adjustment of the secondary battery by the capacity adjustment means is performed further at the time of charging,
Since the voltage difference between each of the secondary batteries which becomes the largest at the time of charging is reduced, the battery voltages of the plurality of secondary batteries can be further equalized. The capacity adjustment at the time of charging is performed by calculating the dischargeable capacity of each of the secondary batteries based on each battery voltage detected by the battery voltage detecting means at the end of discharging, and calculating the calculated dischargeable capacity. This is performed by the capacity adjusting means. This adjustment may be made, for example, such that the charging current corresponding to the dischargeable capacity is bypassed. At this time, if the capacity adjustment performed during at least one of the charging pause and the discharge pause is corrected,
The capacity adjustment by the capacity adjusting means can be accurately performed. Further, the capacity adjustment at the time of charging is performed by the capacity adjusting means based on the voltage difference between the respective battery voltages detected by the battery voltage detecting means at the end of charging so that the voltage difference between the respective battery voltages becomes smaller. For example, the battery voltage of each secondary battery can be further equalized. This adjustment may be made, for example, such that when the voltage difference exceeds a preset value, a current corresponding to a capacity corresponding to the voltage difference is bypassed.

A second aspect of the present invention is a module battery unit provided with a module battery control device. As described above, the module battery control device can efficiently and uniformly charge and discharge the module battery, and can be configured to detect an abnormal state and an excessive state. Since the secondary battery can be protected from charging and overdischarging, an excellent module battery unit can be realized.

A third aspect of the present invention is a module battery control method for controlling a module battery in which a plurality of secondary batteries are connected in series, the method comprising controlling at least one of a charging pause and a discharge pause. Detecting the battery voltage of each of the plurality of secondary batteries, and calculating a capacity corresponding to the voltage difference when a voltage difference between the detected battery voltages exceeds a preset value; Discharging the current corresponding to the calculated capacity during at least one of a charging pause and a discharge pause. In this case, the battery voltage of each of the plurality of secondary batteries at the end of discharge is detected, and each of the other secondary batteries is determined based on the minimum battery voltage among the detected battery voltages at the end of discharge. Calculating the dischargeable capacity of the secondary battery at the time of the next charge at the end of the discharge, bypassing the charge current of the other secondary battery corresponding to the calculated dischargeable capacity, and calculating the plurality of secondary batteries at the end of charge. Is detected, and when the detected voltage difference between the battery voltages at the end of charging exceeds a preset value, the charging current corresponding to the voltage difference is bypassed before charging is completed. , May be further included. Further, in the step of calculating the dischargeable capacity, the calculation may be performed by subtracting a capacity discharged in at least one of the charging pause and the discharge pause.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a module battery unit to which the present invention is applied will be described with reference to the drawings.

(Configuration) As shown in FIG. 1, the module battery unit 10 of the present embodiment includes a plurality of secondary batteries B1, B
.., Bn are connected in series and a module battery control device for controlling the module batteries.

The module battery control device includes a microcomputer (hereinafter referred to as a microcomputer) 1. The microcomputer 1 includes a CPU that performs arithmetic processing, a program that the CPU executes, and an RO that stores various setting values described below.
M, a RAM serving as a work area for the CPU, an input / output interface serving as a port for input / output signals with the outside, and the like.

The module battery control devices are disposed in contact with the surfaces of the respective secondary batteries B1, B2,... Bn, and measure thermistors 71, 7 for measuring the temperatures of the respective secondary batteries.
2,... 7n. Thermistors 71, 72,
.. 7n are connected to a battery temperature detection circuit 3 which converts a resistance (voltage) value measured by these thermistors into a temperature value and outputs it to the microcomputer 1.

Further, the module battery control device includes a battery voltage detecting circuit 2 for detecting a battery voltage of each secondary battery. As shown in FIG. 2, the battery voltage detection circuit 2 is configured to have the same number of operational amplifier circuits as the number of secondary batteries, each including an operational amplifier IC1 and resistors R11 to R15. The positive-phase input terminal of the operational amplifier IC1 of each operational amplifier circuit is connected to the plus terminal of each secondary battery via a resistor R12, and the negative-phase input terminal is connected to the minus terminal of each secondary battery via a resistor R11. , Output terminal is microcomputer 1
It is connected to the. Therefore, taking the secondary battery B1 as an example, the voltage output from the output terminal of the operational amplifier IC1 is the potential V1 of the secondary battery B1 and the potential V2 of the secondary battery B2.
, That is, the voltage of the secondary battery B1.

As shown in FIG. 1, the module battery control device is connected in parallel with the secondary batteries B1, B2,... Bn, adjusts the battery capacity of each secondary battery, and has the same circuit configuration. 6n are provided. As shown in FIG. 3, for example, the capacitance adjustment circuit 61
Channel MOS type FET Q1, NPN type transistor Q
2 and resistors R1 to R6. The drain of the FET Q1 is connected to the plus terminal of the secondary battery B1 via the resistor R1, the source is connected to the minus terminal of the secondary battery B1, and the base of the transistor Q2 is connected via the resistor 4. Connected to the microcomputer 1. Therefore, when the microcomputer 1 outputs a small current (adjustment signal) of a predetermined voltage from the microcomputer 1, a current flows through the gate of the FET Q1.
This is a circuit configuration in which a current flows from the drain to the source of Q1.

Further, as shown in FIG. 1, the module battery control device detects a voltage value of the module battery and outputs the voltage value to the microcomputer 1, a charging / discharging current using the shunt (shunt) resistance as a sensor. Sensor 8 measures the voltage as a voltage value. The voltage value across the shunt resistor measured by the current sensor 8 is converted to a current value, and the default value -1 is set when the module battery is charging, and the default value is set when the module battery is discharging. A charge / discharge current detection circuit 5 that outputs a value 1 to the microcomputer 1 when charging or suspension of charging is performed and a default value 0 is provided, and a cutoff switch 9 for cutting off the charge / discharge current.

The cut-off switch 9 can be an FET, a relay, or the like. The cut-off switch 9 can be turned on and off by a cut-off signal from the microcomputer 1, and can be used for charging the module battery after discharging is completed. In this configuration, the switch can be manually released from OFF to ON.

(Operation) Next, the operation of the module battery unit 10 of the present embodiment will be described with reference to a flowchart. When the power of the microcomputer 1 is turned on, the CPU of the microcomputer 1 initializes a work area of the RAM according to a program stored in the ROM, reads various setting values described later stored in the ROM, and shifts to the RAM. And the execution of the module battery control processing routine shown in FIG. 4 is started.

In step 100 of FIG. 4, each secondary battery B
The protection processing subroutine shown in FIG. 5 is executed in order to protect 1, B2,... Bn from abnormal voltage or the like. First, in step 102, the module voltage value output from the module voltage detection circuit 4 is fetched, and in the next step 104
At the time, the acquired module voltage value is
In order to detect whether or not the module voltage upper limit set value transferred into the AM work area is larger than the module voltage upper limit set value, whether or not the module voltage value is smaller than the module voltage lower limit set value, and a cell short circuit, etc. (See step 272) Voltage change amount ΔV / Δt per time between the voltage value stored in the RAM (the voltage set value transferred to the RAM only when this step is executed first) and the voltage value detected this time
Is determined, and it is determined whether or not the voltage of the module battery is abnormal by determining whether or not the absolute value of the calculated voltage change amount ΔV / Δt is larger than the voltage change amount set value. Therefore, in step 104, an affirmative determination is made that any one of the upper limit, the lower limit, and the voltage change amount ΔV / Δt is out of the set range. In the case of a negative determination, since there is no abnormality in the voltage of the entire module battery, in the next step 106, each temperature value of each secondary battery output from the battery temperature detection circuit 3 is fetched.

Next, at step 108, it is detected whether each of the taken temperature values is larger than the battery temperature upper limit set value, whether each temperature value is smaller than the battery temperature lower limit set value, and a sharp temperature rise. For this reason, the previous time (step 274 in FIG. 6)
Reference) Temperature change amount ΔT per time between each temperature value stored in the RAM (the temperature set value transferred to the RAM only when this step is executed first) and each temperature value detected this time.
/ Δt is calculated, and it is determined whether or not the absolute value of the calculated temperature change amount ΔT / Δt is greater than the temperature change amount set value, thereby determining whether or not each secondary battery has a temperature abnormality. Therefore, in this step, an affirmative determination is made that any one of the upper limit, the lower limit, and the temperature change amount ΔV / Δt is out of the set range. In the case of a negative determination, since there is no temperature abnormality in all the secondary batteries, the next step 11
0, each secondary battery B output from the battery voltage detection circuit 2
1, B2, takes in the battery voltage _{V B} of · · · Bn R
Stored in the AM, in step 112, by the battery voltage V _B taken to determine whether less or not than the large squid whether and secondary battery lower limit voltage set value than the secondary battery voltage upper limit set value, the It is determined whether the secondary battery has a voltage abnormality.

In the case of a negative determination, since there is no abnormal voltage in the battery voltages of all the secondary batteries, in the next step 114, each battery voltage V stored in the RAM in step 110 is read.
By determining whether or not _B is greater than the overcharge set value, it is determined whether or not each secondary battery is in an overcharged state. If the determination is negative, since any of the secondary batteries also are not overcharged, at the next step 116, by determining whether the battery voltage V _B is less than the over-discharge setting value, each It is determined whether the secondary battery is in an over-discharge state. In the case of a negative judgment, there is no abnormality in the module voltage, battery temperature, and each secondary battery voltage necessary for each secondary battery protection, and each secondary battery is not in an overcharged or overdischarged state. In step 118, a high-level binary output signal is output to the cutoff switch 9, the protection processing subroutine ends, and the routine proceeds to step 200 in FIG. As a result, when the cutoff switch 9 is off, it is turned on and the cutoff state is released, and when the cutoff switch 9 is turned on, the on state is maintained. The state is maintained.

On the other hand, steps 104, 108, 112,
If an affirmative determination is made in 114 or 116, there is an abnormality in any of the module voltage, each secondary battery temperature, and each secondary battery voltage, or the battery is overcharged or overdischarged. In order to turn off the cutoff switch 9, a low-level binary output signal (cutoff signal) is output to the cutoff switch 9, the protection processing subroutine ends, and the routine proceeds to step 200. As a result, the module battery unit 10 is temporarily disabled as a power source. If it is determined in steps 108, 112, 114, and 116 that even one secondary battery is abnormal, the process proceeds to step 120 to protect all the secondary batteries.

Next, in step 200 of FIG. 4, in order to detect the charge / discharge state of the module battery and adjust the capacity of each of the secondary batteries B1, B2,... Bn according to the state of the module battery, The capacity adjustment processing subroutine shown in FIG. 6 is executed.

In step 202 of FIG. 6, a default value output from the charge / discharge current detection circuit 5 is fetched and RA
M, and determines whether or not the module battery unit 10 is discharging by determining whether the default value is 1 or not. If the determination is affirmative, in the next step 204, by the battery voltage V _B of each of the secondary batteries to determine whether less or not than the discharge termination voltage set value, it is determined whether to terminate the discharge. If a negative determination is made, the process proceeds to the next step 272. As a result, the module battery unit 10 continues the discharging state.
On the other hand, if an affirmative determination is made in step 204, the process proceeds to the next step 210 in order to prevent the performance of the secondary battery from deteriorating due to overdischarge and to calculate a basic value of the adjustment capacity adjustment during charging described later.

In step 210, a discharge termination processing subroutine shown in FIG. 7 is executed. In this discharge termination processing subroutine, in step 212, the cutoff switch 9
Outputs a shutoff signal to detect the battery voltage V _B of the respective secondary batteries in the next step 214. Next, in step 216,
(Battery voltage initially reaches the discharge end voltage) lowest cell voltage in the battery voltage V _B of the battery as a reference, individually dischargeable discharge capacity to a discharge end voltage of other secondary batteries In the next step 218, the calculation result is stored in a predetermined area of the RAM, the discharge termination processing subroutine ends, and the routine proceeds to step 272.

On the other hand, if a negative determination is made in step 202 of FIG. 6, in the next step 206, it is determined whether or not the default value stored in the RAM in step 202 is -1 to determine that the battery is being charged. It is determined whether or not. In the case of a negative determination, since neither discharging nor charging is being performed, it is determined that the discharging or the charging is stopped, and the process proceeds to the next step 220. On the other hand, if the determination is affirmative, in step 208, reads a battery voltage V _B of the battery stored in the RAM in step 110, the end of charging voltage of the battery voltage V _B is shifted in the RAM of each of the secondary batteries By judging whether or not it is larger than the set value, it is judged whether or not it is the end of charging. In the case of an affirmative determination, the capacity adjustment A processing subroutine shown in FIG. 8 is executed in the next step 220 as in the case of a negative determination in step 206.

[0034] At step 222 of FIG. 8, the smallest cell voltage by reading the battery voltage _{V B} of the respective secondary batteries Vmi
As n, calculates the voltage difference _{V D} obtained by subtracting the Vmin from the battery voltage _{V B} of the battery _{(V D} = V B -Vmin), migrated voltage from the voltage difference _{V D} in the next step 224 in the RAM The difference setting value is read out, and the difference D between them is equal to the voltage difference V _D −
(Voltage difference set value) is calculated.

In the next step 226, the adjustment capacity Q (or Q ') described below is calculated only for each secondary battery having a positive difference D, and only the calculation result adjustment capacity Q' is stored in the RAM. In step 228, an adjustment time t (or t ′) corresponding to the adjustment capacity Q (or Q ′) is calculated,
In step 230, the output of the adjustment signal to the capacity adjustment circuit 6 connected in parallel to the secondary battery that needs to be adjusted is started.

As a result, the capacity adjustment circuit 6 starts capacity adjustment. The capacity adjustment by the capacity adjustment circuit 6 is different between the last stage of charging (the same applies to the later-described charging) and the charging pause or the discharging pause. take. That is, at the end of charging,
For example, when an adjustment signal is output to the capacity adjustment circuit 61 shown in FIG. 3, the charging current I flows through the secondary battery B1, and when the N-channel MOSFET Q1 is turned on,
A current Ia flows from the drain to the source. As a result, the current (I-Ia) flows through the secondary battery B1, and the charge amount corresponding to the current Ia is adjusted. The current Ia is determined by the resistor R1, and the adjusted capacitance Q to be adjusted is the product of the current Ia and the adjustment time t. On the other hand, when the adjustment signal is output to the capacity adjustment circuit 61 at the time of suspension of charging or discharging, as shown in FIG. 10, when the FET Q1 is turned on, the secondary battery B1 is charged differently from the case of FIG. No current flows, secondary battery B1, resistor R1, FE
In the closed circuit constituted by TQ1, the secondary battery B1 is in a discharged state. At this time, when the current flowing through the closed circuit to ignore the internal resistance of the Ib secondary battery B1, the resistance value of the resistor R1 are known, the current Ib is determined by the battery voltage V _B of the secondary battery B1, it is adjusted The adjustment capacitance Q ′ is the product of the current Ib and the adjustment time t ′.

In step 232, it is determined whether or not the adjustment time t (or t ') calculated in step 228 has elapsed. This adjustment time t (or t ′) can be measured by an internal clock (not shown) of the microcomputer 1. If the determination is affirmative, in step 233, the adjustment signal output to the capacity adjustment circuit 6 to cancel the capacity adjustment of the secondary battery is turned off. Thus, for example, the current Ia (or Ib) does not flow between the drain and the source of the N-channel MOSFET Q1 shown in FIG. 3 (or FIG. 10), so that the capacity adjustment circuit 61 adjusts the capacity of the secondary battery B1. Ends.

In the next step 234, step 202
In step 236, the default value stored in the RAM is read to determine whether or not the charging / discharging is paused.
When the determination is affirmative, in the next step 235, the adjustment capacity Q ′ stored in the RAM in step 228 is read out, and the adjustment capacity Q ′ adjusted during the current charge / discharge pause is stored during the previous charge / discharge pause. RA is added to the adjusted capacity
Stored in M. Therefore, the adjusted capacity is stored in the RAM only when the charging and discharging are stopped. Next, in step 236, it is determined whether or not there is another secondary battery that needs to be adjusted. If the determination is affirmative, step 230 is performed in order to continuously adjust the capacity of the secondary battery that needs to be adjusted.
The process returns to step 272. If the determination is negative, the capacity adjustment A processing subroutine ends, and the process proceeds to step 272.

On the other hand, if a negative determination is made in step 232, it is determined in step 238 whether or not it is the end of charging. If the determination is affirmative, the process returns to step 230 to complete the charging. Next step 240
, The default value output from the charge / discharge current detection circuit 5 is fetched and the default value is 1 (discharge) or -1.
By determining whether or not (charging), it is determined whether or not the charging suspension state or the discharging suspension state has been forcibly terminated. When the determination is negative (default value 0), the sleep state is continuing, and the process returns to step 230 to continue the capacity adjustment, and when the determination is affirmative, in step 242, the capacity adjustment of all the secondary batteries is performed. The adjustment signal output to the capacitance adjustment circuit 6 for canceling is turned off. In the next step 244, the adjusted capacity Q ″ for each secondary battery is calculated back from the adjusted time t ″, and the capacity Q ″ adjusted during the suspension in step 246 is calculated up to the previous time. Then, the capacity adjusted during the suspension of charge / discharge is added and accumulated in the RAM, the capacity adjustment A processing subroutine is terminated, and the routine proceeds to step 272.

Next, if a negative determination is made in step 208 of FIG. 6, the routine proceeds to step 250, where the capacity adjustment B processing subroutine shown in FIG. 9 is executed. In step 252, the correction of the adjustment capacity is executed. The correction of the adjustment capacity is performed based on the adjustment capacity calculated from the end-of-discharge voltage stored in the RAM in step 218 or step 235 or step 2.
At 46, the adjustment is performed by subtracting the already adjusted total adjusted capacity at the time of charging / discharging suspension stored in the RAM. In the next step 254, it is determined whether or not the capacity adjustment is necessary by determining whether or not the adjusted capacity after the correction is larger than the adjusted capacity set value transferred to the RAM. When the determination is affirmative, the adjustment time is calculated in step 256, and the adjustment signal is applied in step 258 until the adjustment time elapses in step 260. Output to the capacity adjustment circuit 6 which is to be executed. As a result, the capacity adjustment of the corresponding secondary battery is executed at the time of the next charging after the suspension of charging and discharging. In step 256, the total adjustment amount stored in the RAM is cleared to 0 after calculating the adjustment time to prepare for the next correction.

In the next step 262, the adjustment signal output to the capacity adjusting circuit 6 of the secondary battery is turned off in order to cancel the capacity adjustment of the secondary battery. Next, in step 264, it is determined whether or not there is another secondary battery that needs to be adjusted. If it is necessary, the capacity adjustment is continued, and the adjustment time of the last secondary battery that needs adjustment is adjusted. When the time has elapsed, the capacity adjustment processing B subroutine ends, and the routine proceeds to step 272.

Next, in step 272 of FIG. 6, the module voltage is fetched and stored in the RAM in order to enable the calculation of the voltage change amount ΔB / Δt in step 104 described above. In order to enable the calculation of the amount of temperature change in step 108, each temperature value of each secondary battery is fetched and stored in the RAM, and the process returns to step 100.

(Effects, etc.) Next, eight secondary batteries B1, B
2... B8 are connected in series, an example of the module battery unit 10 of the present embodiment, and a conventional example in which eight secondary batteries are also connected in series to confirm the effect of the example (this embodiment) And a comparative example of a module battery unit (not including the module battery control device of the embodiment), charging and discharging were performed, and a discharge end voltage was measured to confirm the effect of the module battery unit 10 of the present embodiment. In addition, in the module battery unit 10 of the present embodiment, a secondary battery having a voltage variation intentionally was used.

FIGS. 11 and 12 show the measurement results of the discharge end voltage of the module battery units of the example and the comparative example, respectively.
Shown in

As shown in FIG. 11, in the module battery unit 10 of this embodiment, at the beginning, there was a voltage difference between the secondary batteries (cell 1 to cell 8). The voltage difference is decreasing,
Even if a difference occurs, the capacity is adjusted and is about to fall within about 50 mV.

On the other hand, in the module battery unit of the comparative example, as shown in FIG. 12, the voltages were almost the same at the beginning, but the voltage difference increased as the cycle progressed. It can be seen that the secondary batteries connected in series are evenly adjusted by the module battery control device of the battery unit 10.

In the present embodiment, in the capacity adjustment A processing subroutine, when the battery voltage of each secondary battery detected by the battery voltage detection circuit 5 at the end of charging exceeds the set value and fluctuates, the capacity adjustment circuit 6 Bypass charging current (Fig. 3
In addition, at the time of charging / discharging suspension, the variation of the open voltage caused by the difference in the internal resistance and the charging current of each secondary battery is used to discharge the secondary battery having a high open voltage by the capacity adjusting means 6 and the battery voltage of each secondary battery. (See FIG. 10), the battery voltage of each secondary battery can be equalized. In addition, since the capacity adjustment is performed when there is variation over the set value, it is possible to save the consumption of the capacity charged in each secondary battery.

In the discharge end processing subroutine, the secondary battery having the lowest voltage among the battery voltages of the secondary batteries detected at the end of discharge (the secondary battery which first reaches the discharge end voltage) is used as a reference. Calculate the discharge capacity of each of the secondary batteries up to the discharge cutoff voltage (Step 2).
16) In the capacity adjustment B processing subroutine, the capacity of each secondary battery is adjusted during charging by bypassing the charging current at the next charging (steps 258 and 260).
The battery voltage of each secondary battery can be equalized.

Further, in the capacity adjustment B processing subroutine,
Since the correction is performed by subtracting the capacity adjusted at the time of the discharge suspension from the adjusted capacity calculated from the end-of-discharge voltage (Step 252), more accurate capacity adjustment can be performed as compared with the case where no correction is performed. Excessive adjustment can be prevented.

When the module voltage of the module battery, the temperature of each secondary battery, the abnormality of the voltage of each secondary battery, and the overcharge or overdischarge are detected in the protection processing subroutine, the charge / discharge current is cut off. Module battery unit 10
Since the charging and discharging of the secondary battery are stopped, it is possible to protect the secondary battery without deteriorating its performance.

Therefore, the module battery control device of the module battery unit 10 of the present embodiment can charge and discharge each secondary battery efficiently and uniformly, which is apparent from the evaluation of the examples.

In the module battery unit 10 of the present embodiment, the thermistor 7 is disposed in contact with each secondary battery in order to protect all the secondary batteries. It is sufficient that at least one battery is provided for an arbitrary secondary battery, such as being arranged every other battery.
In this case, although it is inferior from the viewpoint of secondary battery protection, there is an advantage that cost can be saved.
Further, in the present embodiment, an example has been described in which the thermistor 7 is used as a temperature sensor, but various sensors that function as a temperature sensor other than the thermistor can be used.

Further, in this embodiment, an example in which a plurality of battery voltage detection circuits 2 shown in FIG. 2 are provided has been described.
The battery voltage of each secondary battery may be detected by one differential amplifier circuit by switching with a switch or the like.

Further, in the present embodiment, FIG. 3 shows an example of the capacitance adjusting circuit 61 as the capacitance adjusting means. However, the present invention is not limited to the circuit configuration shown in FIG. It will be apparent to those skilled in the art that various circuit configurations are possible.

In this embodiment, the shunt resistor and the charging / discharging current detecting circuit 5 are exemplified as the state detecting means. However, other various sensing circuits capable of detecting the charging / discharging state can be constructed. It is clear to Furthermore, in the charging / discharging current detection circuit 5 of the present embodiment, the default value during charging pause or discharging pause is set to 0 for simplicity, but an error due to noise or the like occurs in the voltage between both ends of the shunt resistor. In some cases, it is preferable to use a charge / discharge current detection circuit that takes this error into account.

In the flowchart of this embodiment, one form of control by the microcomputer 1 has been described. However, the present invention is not limited to this, and various modifications can be applied within the scope described in the claims. It is also clear that

[0057]

As described above, according to the present invention, the voltage difference (open-circuit voltage difference) between a plurality of secondary batteries at the time of charging / discharging pause caused by the difference in the internal resistance of the secondary battery and the charging current during charging. ) Can be adjusted to be small, so that the effect that the battery voltage of each secondary battery can be equalized can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of a module battery unit to which the present invention is applied.

FIG. 2 is a circuit diagram illustrating a battery voltage detection circuit of the module battery control device according to the embodiment.

FIG. 3 is a circuit diagram showing a capacity adjustment circuit of the module battery control device of the embodiment.

FIG. 4 is a flowchart illustrating a module battery control processing routine of the module battery control device according to the embodiment;

FIG. 5 is a flowchart showing details of a protection processing subroutine of a module battery control processing routine.

FIG. 6 is a flowchart showing details of a capacity adjustment processing subroutine of a module battery control processing routine.

FIG. 7 is a flowchart showing details of a discharge termination processing subroutine in a capacity adjustment processing subroutine.

FIG. 8 shows a capacity adjustment A in a capacity adjustment processing subroutine.
It is a flowchart which shows the detail of a processing subroutine.

FIG. 9 shows a capacity adjustment B in a capacity adjustment processing subroutine.
It is a flowchart which shows the detail of a processing subroutine.

FIG. 10 is an explanatory circuit diagram showing an operation of the capacity adjustment of the capacity adjustment circuit at the time of charging / discharging suspension.

FIG. 11 is an explanatory diagram showing a measurement result of a discharge end voltage of a module battery unit of an example to which the present embodiment is applied.

FIG. 12 is an explanatory diagram showing a measurement result of a discharge end voltage of a module battery unit of a comparative example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Microcomputer (part of battery temperature detection means, part of cut-off means) 2 Battery voltage detection circuit (part of battery voltage detection means) 3 Battery temperature detection circuit (part of battery temperature detection means) 4 Module voltage detection circuit (Part of module voltage detecting means) 5 Charge / discharge current detecting circuit (part of state detecting means) 61, 62, 6n Capacity adjusting circuit (part of state detecting means) 71, 72, 7n Thermistor (battery temperature detecting means) 8) Current sensor (part of state detection means) 9 Cutoff switch (part of cutoff means) 10 Module battery unit B1, B2, Bn Secondary battery

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02J 7/10 H02J 7/10 LF term (Reference) 2G016 CA03 CB11 CB12 CB31 CB33 CC01 CC03 CC04 CC12 CC27 CC28 CD04 CD06 CD14 5G003 AA01 BA03 CA01 CA11 CB01 CC04 DA07 DA12 DA13 GA01 GC05 5H030 AA03 AA04 AA06 AS08 BB01 BB21 DD08 FF22 FF43 FF44 5H115 PG04 PI14 PI16 QN03 QN12 TI01 TI05 TI06 TI10 TU12 TU16 TU17

Claims (14)

[Claims] 1. A module battery control device for controlling a module battery in which a plurality of secondary batteries are connected in series, a battery voltage detecting means for detecting a battery voltage of each of the plurality of secondary batteries, and the module State detection means for detecting a charge / discharge state of a battery, connected in parallel to each of the plurality of secondary batteries, and a charge pause state and a discharge pause state among the charge / discharge states detected by the state detection means. A capacity adjusting means for adjusting the capacity of the secondary battery based on each of the battery voltages detected by the battery voltage detecting means in a state including at least one of the battery voltages so that a voltage difference between the respective battery voltages is reduced; And a module battery control device comprising: 2. The capacity adjustment by the capacity adjusting means, wherein, when the voltage difference exceeds a preset value, a current corresponding to a capacity corresponding to the voltage difference is discharged. 2. The module battery control device according to 1. 3. The battery module according to claim 1, further comprising a cut-off unit that shuts off charging and discharging of the module battery when each battery voltage detected by the battery voltage detection unit exceeds a preset value. The module battery control device according to claim 1 or 2, wherein: 4. A module voltage detecting means for detecting a module voltage of the module battery and / or a battery temperature detecting means for detecting a battery temperature of at least one of the plurality of secondary batteries. Wherein the shutoff means cuts off the charging and discharging of the module battery when at least one of the module voltage and the battery temperature exceeds a preset value. 4. The module battery control device according to 3. 5. The module battery control device according to claim 1, wherein the capacity adjustment of the secondary battery by the capacity adjustment unit is further performed during charging. 6. The capacity adjustment at the time of charging includes calculating a dischargeable capacity of each of the secondary batteries based on each battery voltage detected by the battery voltage detecting means at the end of discharging,
The module battery control device according to claim 5, wherein the calculated dischargeable capacity is adjusted by the capacity adjusting means. 7. The module battery control device according to claim 6, wherein the adjustment by the capacity adjusting unit bypasses a charging current corresponding to the dischargeable capacity. 8. The capacity adjustment at the time of charging, wherein the capacity adjustment performed during at least one of the charging pause and the discharge pause is corrected. The module battery control device according to claim 1. 9. The battery according to claim 1, wherein the capacity adjustment during charging is performed such that the voltage difference between the respective battery voltages is reduced based on the voltage difference between the respective battery voltages detected by the battery voltage detecting means at the end of charging. The module battery control device according to any one of claims 6 to 8, wherein the capacity is adjusted by the capacity adjusting means. 10. The adjustment by the capacitance adjusting means, when the voltage difference exceeds a preset value, bypasses a current corresponding to the capacitance corresponding to the voltage difference. 3. The module battery control device according to claim 1. 11. The method according to claim 1, wherein
A module battery unit provided with the module battery control device according to the above section. 12. A module battery control method for controlling a module battery in which a plurality of secondary batteries are connected in series, wherein said plurality of secondary batteries are in at least one of a state in which charging is stopped and a state in which discharging is stopped. When the voltage difference between the detected battery voltages exceeds a preset value, a capacity corresponding to the voltage difference is calculated. Discharging the current corresponding to the calculated capacity in at least one of the states. 13. A battery voltage of each of the plurality of secondary batteries at the end of discharge is detected, and another secondary battery is determined based on a minimum battery voltage among the detected battery voltages at the end of discharge. Calculating the respective dischargeable capacities, at the time of the next charge at the end of the discharge, bypassing the charge current of the other secondary battery corresponding to the calculated dischargeable capacity; Detecting the battery voltage of each of the batteries, and when the detected voltage difference between the battery voltages at the end of charging exceeds a preset value, bypasses the charging current corresponding to the voltage difference before the completion of charging. The method according to claim 12, further comprising the step of: 14. The method according to claim 13, wherein the step of calculating the dischargeable capacity is performed by subtracting a capacity discharged during at least one of the charging pause and the discharge pause. Module battery control method.