JP2012222837A - Secondary battery charge control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary battery charge control system capable of charging even the secondary batteries having variation in capacity, connected in series, up to a nearly full charge state.SOLUTION: A secondary battery charge control system 100 includes a battery row 1A in which two or more secondary batteries 1a, 1b, ..., 1n are connected in series, a current generator 4 for generating a current to flow through the battery row 1A, and a charge control device 2 for controlling a generated current of the current generator 4. The charge control device 2 decreases a generated current of the current generator 4 stepwise every time any single voltage value of secondary batteries 1a, 1b, ..., and 1n constituting the battery row 1A reaches a control voltage value being set in advance.

Description

  The present invention relates to an invention relating to a secondary battery charge control system that charges a secondary battery while preventing overcharge.

  The secondary battery can be repeatedly charged and discharged. On the other hand, in a secondary battery such as lithium ion, it is necessary to prevent overcharging from the viewpoint of battery safety. As a prior art for preventing overcharge of a secondary battery, for example, Patent Document 1 exists.

  In the technology according to Patent Document 1, the terminal voltage of each cell constituting the non-aqueous secondary battery is detected, and charging is stopped when the terminal voltage of any cell exceeds a preset voltage.

  For example, Patent Document 2 and Patent Document 3 also exist as other prior art documents for preventing overcharge / overdischarge of the secondary battery.

Japanese Patent Laid-Open No. 5-111175 Japanese Patent Laid-Open No. 5-115129 Japanese Patent Laid-Open No. 11-113184

  However, the technique disclosed in the above-mentioned Patent Document 1 (that is, if a voltage value that is overcharged is set and the voltage value is detected even once, the charging current is immediately cut off to complete the charging) In the control method, the following problems occur.

  That is, in this control method, the fully charged state is not achieved due to the charging characteristics of the unit cell. Further, in the secondary batteries connected in series, there is generally variation in battery capacity among the secondary batteries. Therefore, when the control method is employed, charging is stopped even though there is a secondary battery that can still be charged. In other words, if the charging is terminated immediately when the single voltage value reaches the set voltage value in any of the secondary batteries, there is a variation in the characteristics of each secondary battery. The battery voltage also has a deviation in each secondary battery at the end. Therefore, even when one secondary battery reaches the set voltage, some other secondary batteries are insufficiently charged. That is, in the secondary batteries connected in series, there are secondary batteries that are almost fully charged, and there are secondary batteries that are insufficiently charged. This means that the charge amount of all the secondary batteries is terminated with an amount smaller than the target.

  Therefore, the present invention can charge each secondary battery connected in series with a capacity variation in a state close to a fully charged state (that is, all secondary batteries connected in series). It is an object of the present invention to provide a secondary battery charge control system that can increase the total charge amount of the secondary battery and prevent overcharge.

  In order to achieve the above object, a secondary battery charge control system according to the present invention includes a battery array in which at least two or more secondary batteries are connected in series, and a current generator that generates a current that flows through the battery array. And a control device for controlling the current generated by the current generator, the control device is set with a control voltage value, and the control device is one of the battery trains. Each time the single voltage value of the secondary battery reaches the control voltage value, the generated current of the current generator is lowered step by step.

  Moreover, the secondary battery charge control system according to the present invention includes a battery group in which at least two or more secondary batteries are connected in series, a battery group connected in parallel, and a current that generates a current that flows through the battery group. A generator and a control device for controlling the current generated by the current generator, wherein the control device is set with a control voltage value, and the control device includes any one of the battery groups. Each time the single voltage value of the secondary battery reaches the control voltage value, the generated current of the current generator is reduced stepwise.

  A secondary battery charge control system according to the present invention includes a battery array in which at least two or more secondary batteries are connected in series, a current generator that generates a current to flow through the battery array, and a current generated by the current generator. A control voltage value is set in the control device, and the control device has a single voltage value of any one of the secondary batteries constituting the battery array. Each time the control voltage value is reached, the generated current of the current generator is decreased stepwise.

  Alternatively, the secondary battery charging control system according to the present invention includes a battery group in which at least two or more secondary batteries are connected in series, a battery group connected in parallel, and a current that generates a current that flows through the battery group. A generator and a control device for controlling the current generated by the current generator, wherein the control device is set with a control voltage value, and the control device includes any one of the battery groups. Each time the single voltage value of the secondary battery reaches the control voltage value, the generated current of the current generator is reduced stepwise.

  Therefore, even if the single voltage value of any secondary battery reaches the control voltage value, the charging current flowing through the secondary battery is not immediately stopped. In other words, although the current value is lowered, the charging current can continue to flow to each secondary battery, and even if the charging current is continued, the single voltage value of the secondary battery exceeds the control voltage value and safety cannot be ensured. It does not reach a voltage value that causes voltage or deterioration.

  In this way, even if the single voltage value of any secondary battery reaches the control voltage value, the charging current (although the current value decreases stepwise) flowing through each secondary battery can be continued. Therefore, it is possible to charge all secondary batteries in a state close to a fully charged state even for each secondary battery having a capacity variation (that is, to increase the total charge amount of all the secondary batteries). Can do).

1 is a circuit diagram showing a configuration of a secondary battery charge control system 100 according to Embodiment 1. FIG. It is a figure which shows the charge characteristic of one secondary battery. 6 is a circuit diagram showing a configuration of a secondary battery charge control system 200 according to Embodiment 2. FIG.

  Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.

<Embodiment 1>
FIG. 1 is a circuit diagram showing a configuration of a secondary battery charging control system 100 according to the first embodiment.

  As shown in FIG. 1, the secondary battery charge control system 100 according to the first embodiment includes a plurality (at least two or more) of secondary batteries 1a, 1b,. The battery monitoring device 3 </ b> A and the current generator 4 are configured.

  Secondary batteries 1a, 1b,..., 1n are, for example, lithium ion secondary batteries, and are connected in series. A configuration in which a plurality of secondary batteries are connected in series is referred to as a “battery row” 1A.

  The battery monitoring device 3A incorporates an AD converter and detects a single voltage of each of the secondary batteries 1a, 1b,..., 1n constituting the battery array 1A. The battery monitoring device 3A also detects a column current flowing through the battery column 1A.

  The current generator 4 is disposed between one end and the other end of the battery array 1A, generates a constant current having a specified current value, and allows the generated constant current to flow to the battery array 1A. it can. Here, the designated current value is variable.

  The charging control device 2 has a built-in charging circuit, and inputs a single voltage value of each secondary battery 1a, 1b,..., 1n detected by the battery monitoring device 3A and a column current value flowing through the battery column 1A. Is done. Further, the charging control device 2 generates a current generated by the current generator 4 (that is, a specified current value) based on the single voltage value of each of the secondary batteries 1a, 1b,. ) Is controlled.

  FIG. 2 is a diagram showing charging characteristics of one secondary battery such as lithium ion.

  FIG. 2 shows the relationship between the charging current flowing through the secondary battery, the battery voltage of the secondary battery, and the charging capacity of the secondary battery.

  As shown in the secondary battery characteristics of FIG. 2, a constant current flows through the secondary battery until the battery voltage of the secondary battery reaches the control voltage value, and the charge capacity of the secondary battery increases proportionally. To do. In addition, as shown in FIG. 2, when the charging current flowing through the secondary battery is lowered, the battery voltage of the secondary battery has a phenomenon (characteristic) that decreases. Therefore, every time the battery voltage of the secondary battery reaches a predetermined voltage value (control voltage value to be described later), the charging current flowing to the secondary battery is reduced stepwise, and the constant current in the lowered state is supplied to the secondary battery. Shed. As a result, even if the current is low, the charging current can be continuously supplied to the secondary battery, and the charging capacity of the secondary battery can be increased without the battery voltage of the secondary battery exceeding the predetermined voltage value. It can be increased continuously (see FIG. 2).

  In the present embodiment, the charging control device 2 performs the following control on the current generator 4 by utilizing the phenomenon (characteristic) of the secondary battery shown in FIG.

  That is, a control voltage value is set in advance in the charging control device 2. The charging control device 2 generates current in a stepwise manner every time the single voltage value of any of the secondary batteries 1a, 1b,..., 1n constituting the battery array 1A reaches the control voltage value. The generated current (specified current value) of the device 4 is lowered. That is, even if the single voltage value of any of the secondary batteries 1a, 1b,..., 1n constituting the battery array 1A reaches the control voltage value, the charging control device 2 immediately Rather than setting the generated current (specified current value) to zero, the specified current value of the generated current is lowered stepwise to continue constant current control.

  In the charging control device 2, a protection voltage value higher than the control voltage value is also set in advance. Then, when any of the secondary batteries 1a, 1b,..., 1n constituting the battery array 1A reaches the protection voltage value, the charge control device 2 stops the current flowing through the battery array 1A (that is, The generated current (specified current value) of the current generator 4 is set to zero). The control for stopping the current flowing through the battery array 1A is generated in stages even before the above-described control for decreasing the generated current in stages (that is, in a state in which a constant current at an initial specified current value described later is flowing). The control is performed even during the control for reducing the current (that is, a state in which a constant current is supplied at each specified current value other than the initial specified current value).

  Here, the protection voltage value is set from the viewpoint of safety of the secondary batteries 1a, 1b,..., 1n and prevention of deterioration of the secondary batteries 1a, 1b,. That is, when the battery voltage of the secondary batteries 1a, 1b,..., 1n exceeds the protection voltage value, the safety of the secondary batteries 1a, 1b,. Deterioration of 1a, 1b, ..., 1n cannot be prevented. Further, the control voltage value is set slightly lower than the protection voltage value (for example, lower by about a few V).

  Next, the operation of the secondary battery charge control system 100 according to the first embodiment will be described.

  Charging the battery row 1A is started. That is, based on the command from the charge control device 2, the current generator 4 generates a constant current having an initial designated current value I1. Then, the current generator 4 passes the generated constant current to the battery array 1A.

  The battery monitoring device 3A constantly detects the value of the current flowing through the battery row 1A, and the detection result is notified to the charging control device 2. Thereby, the charging control apparatus 2 can confirm that the constant current flowing through the battery array 1A is the initial designated current value I1.

  Further, the battery monitoring device 3A constantly detects the single voltage values of the secondary batteries 1a, 1b,..., 1n constituting the battery array 1A. Then, the battery monitoring device 3A notifies the charge control device 2 also of the detection result.

  In the charging control device 2, the single voltage value of each of the secondary batteries 1a, 1b,..., 1n notified from the battery monitoring device 3A is compared with the control voltage value preset in the charging control device 2. I do.

  As a result of the comparison, if any single voltage value of each of the secondary batteries 1a, 1b,..., 1n has not reached the control voltage value, the charge control device 2 has a new current generator 4. Do not give orders. As a result, the current generator 4 continuously flows the constant current having the initial designated current value I1 to the battery array 1A.

  On the other hand, as a result of the comparison, the charge control device 2 determines that the single voltage value has reached the control voltage value in any one of the secondary batteries 1a, 1b,. To do. In this case, the charging control device 2 issues a new command to the current generator 4. Thereby, the current generator 4 lowers the generated current from the initial designated current value I1 to the designated current value I2, and continuously causes the constant current of the designated current value I2 to flow through the battery array 1A. Here, the initial specified current value I1> specified current value I2> 0.

  In this way, the battery voltage of each of the secondary batteries 1a, 1b,..., 1n is slightly lowered by lowering the charging current flowing through the battery array 1A from the initial designated current value I1 to the designated current value I2. Therefore, even if the constant current having the specified current value I2 is continuously supplied to the battery array 1A, the single voltage value does not immediately exceed the control voltage value in any of the secondary batteries 1a, 1b,. For a while, a constant current having a specified current value I2 can be supplied to the battery array 1A. Therefore, the charge capacity in each secondary battery 1a, 1b, ..., 1n can also be increased continuously.

  As described above, the battery monitoring device 3A constantly detects the value of the current flowing through the battery array 1A, and the detection result is notified to the charging control device 2. Thereby, the charging control apparatus 2 can confirm that the constant current flowing through the battery array 1A has changed to the specified current value I2.

  Further, as described above, the battery monitoring device 3A constantly detects the single voltage values of the secondary batteries 1a, 1b,..., 1n constituting the battery array 1A. Then, the battery monitoring device 3A notifies the charge control device 2 also of the detection result.

  In the charging control device 2, as described above, the single voltage values of the secondary batteries 1a, 1b,..., 1n notified from the battery monitoring device 3A and the control preset in the charging control device 2 are performed. Compare with voltage value.

  As a result of the comparison, if any single voltage value of each of the secondary batteries 1a, 1b,..., 1n has not reached the control voltage value, the charge control device 2 has a new current generator 4. Do not give orders. Thereby, the current generator 4 continuously flows the constant current having the designated current value I2 to the battery row 1A.

  On the other hand, as a result of the comparison, the charge control device 2 again determines that the single voltage value has reached the control voltage value in any one of the secondary batteries 1a, 1b, ..., 1n. And In this case, the charging control device 2 issues a new command to the current generator 4. As a result, the current generator 4 reduces the generated current from the specified current value I2 to the specified current value I3, and continuously supplies a constant current of the specified current value I3 to the battery array 1A. Here, the specified current value I2> the specified current value I3> 0.

  Thus, the battery voltage of each of the secondary batteries 1a, 1b,..., 1n is slightly lowered by lowering the charging current flowing through the battery array 1A from the specified current value I2 to the specified current value I3. Therefore, even if the constant current having the specified current value I3 continues to flow through the battery array 1A, the single voltage value does not immediately exceed the control voltage value in any of the secondary batteries 1a, 1b,. For a while, a constant current having a specified current value I3 can flow through the battery array 1A. Therefore, the charge capacity in each secondary battery 1a, 1b, ..., 1n can also be increased continuously.

  In this way, the charging control device 2 steps the constant current generated by the current generator 4 every time the single voltage value reaches the control voltage value in any one of the secondary batteries 1a, 1b,. Repeatedly lower the control.

  While the initial designated current value I1 is being passed through the battery row 1A or while the designated current values I2, I3, etc., which have been lowered in stages are being passed through the battery row 1A, the battery monitoring device 3A It is assumed that the charging control device 2 makes the following determination based on the notification from. That is, the charge control device 2 indicates that the single voltage value has reached the protection voltage value preset in the charge control device 2 in any one of the secondary batteries 1a, 1b,. Assume that you have determined.

  As described above, the protection voltage value (> control voltage value) is determined from the viewpoint of ensuring the safety of the secondary batteries 1a, 1b,..., 1n or preventing the deterioration of the secondary batteries 1a, 1b,. , Values selected according to the capacity performance of the secondary batteries 1a, 1b,..., 1n. Therefore, when the single voltage of the secondary batteries 1a, 1b,..., 1n reaches the protection voltage value, it is necessary to stop the charging of the secondary batteries 1a, 1b,.

  Therefore, when any one of the secondary batteries 1a, 1b,..., 1n determines that the single voltage value has reached the protection voltage value, the charge control device 2 Then, a signal for stopping the generation of the charging current is transmitted to the current generator 4. Thereby, the current generator 4 can immediately stop the charging current to the battery array 1A (that is, the charging of the secondary batteries 1a, 1b,..., 1n can be stopped).

  Here, unlike the circuit configuration of FIG. 1, a circuit configuration in which a switch is disposed between the current generator 4 and the battery array 1A may be employed. In this case, when any one of the secondary batteries 1a, 1b,..., 1n is determined by the charge control device 2 that the single voltage value has reached the protection voltage value, the charge control is performed. The device 4 transmits a signal instructing “OFF” to the switch. As a result, the switch is turned off, and the current supplied from the current generator 4 to the battery array 1A is immediately cut off (that is, charging of the secondary batteries 1a, 1b,..., 1n can be stopped). .

  As described above, in the secondary battery charge control system 100 according to the first embodiment, the charge control device 2 includes any one of the secondary batteries 1a, 1b,..., 1n constituting the battery array 1A. Each time the voltage value reaches the control voltage value, control is performed to reduce the current generated by the current generator 4 step by step.

  Therefore, even if the single voltage value of any of the secondary batteries 1a, 1b,..., 1n reaches the control voltage value, the charging current flowing through the battery array 1A is not immediately stopped. That is, although the specified current value is lowered, the charging current can continue to flow through the battery array 1A. Even if the charging current is continued, the secondary batteries 1a, 1b,. The single voltage value of 1n exceeds the control voltage value, so that it does not reach a voltage that cannot ensure safety or a voltage value that causes deterioration.

  As described above, in the present embodiment, even when the single voltage value of any of the secondary batteries 1a, 1b,..., 1n reaches the control voltage value, the charging current (specified current value) that flows through the battery array 1A. Can be continued step by step). Therefore, all the secondary batteries 1a, 1b,..., 1n are almost fully charged with respect to the secondary batteries 1a, 1b,. (That is, the total charge amount of all the secondary batteries 1a, 1b, ..., 1n connected in series can be increased).

  Moreover, in the secondary battery charging control system 100 according to the present embodiment, the charging control device 2 is configured such that any of the secondary batteries 1a, 1b,. When it reaches, the control which stops the electric current which flows into 1 A of battery rows is performed. Here, the protection voltage value is a value selected from the viewpoint of ensuring safety of the secondary batteries 1a, 1b,..., 1n and preventing deterioration of the secondary batteries 1a, 1b,. (Protection voltage value> control voltage value).

  Therefore, even if the single voltage of any of the secondary batteries 1a, 1b,..., 1n reaches the protection voltage value for some reason during the flow of the charging current to the battery row 1A, Immediately after reaching, charging of all the secondary batteries 1a, 1b,..., 1n can be terminated. Therefore, it is possible to prevent the secondary batteries 1a, 1b,..., 1n constituting the battery array 1A from being overcharged. As a result, the safety of the secondary batteries 1a, 1b,. And the deterioration of the secondary batteries 1a, 1b, ..., 1n can be prevented.

<Embodiment 2>
The secondary battery charge control system according to the second embodiment has a configuration in which at least two battery rows are connected in parallel. FIG. 3 is a circuit diagram showing a configuration of secondary battery charging control system 200 according to the present embodiment.

  As shown in FIG. 3, the secondary battery charging control system 200 according to the second embodiment includes a plurality of secondary batteries 1a, 1b,..., 1n, 2a, 2b,. The control device 2 includes battery monitoring devices 3A and 3B, a current generator 4, charging semiconductor switches 5A and 5B, and discharging semiconductor switches 6A and 6B.

  Secondary batteries 1a, 1b, ..., 1n, 2a, 2b, ..., 2n are, for example, lithium ion secondary batteries. The secondary batteries 1a, 1b, ..., 1n are connected in series, and the secondary batteries 2a, 2b, ..., 2n are connected in series. A configuration in which secondary batteries 1a, 1b,..., 1n are connected in series is referred to as “battery array” 1A, and a configuration in which secondary batteries 2a, 2b,. This is referred to as “column” 2A. Battery row 1A and battery row 1B are connected in parallel. Here, a configuration including all the secondary batteries 1a, 1b,..., 1n, 2a, 2b,.

  In the configuration example shown in FIG. 3, only two battery rows 1A and 2A are connected in parallel. However, a configuration in which each of three or more battery rows is connected in parallel is applied to the present embodiment. Is also possible. Here, each battery row has a configuration in which at least two or more secondary batteries are connected in series.

  The battery monitoring device 3A incorporates an AD converter and detects a single voltage of each of the secondary batteries 1a, 1b,..., 1n constituting the battery array 1A. The battery monitoring device 3A also detects a column current flowing through the battery column 1A. On the other hand, the battery monitoring device 3B incorporates an AD converter and detects the single voltage of each of the secondary batteries 2a, 2b,..., 2n constituting the battery array 2A. The battery monitoring device 3B also detects a column current flowing through the battery column 2A.

  The charging semiconductor switch 5A and the discharging semiconductor switch 6A are connected in parallel. Here, the forward direction (charging current direction) of the charging semiconductor switch 5A and the forward direction (discharging current direction) of the discharging semiconductor switch 6A are opposite to each other. A parallel configuration of the semiconductor switches 5A and 6A (hereinafter referred to as a first switch parallel configuration) is arranged in series on one end side of the battery array 1A.

  The charging semiconductor switch 5B and the discharging semiconductor switch 6B are connected in parallel. Here, the forward direction (charging current direction) of the charging semiconductor switch 5B and the forward direction (discharging current direction) of the discharging semiconductor switch 6B are opposite to each other. A parallel configuration of the semiconductor switches 5B and 6B (hereinafter referred to as a second switch parallel configuration) is arranged in series on one end side of the battery array 2A.

  The charging current flowing through the battery row 1A is cut off by the turning-off operation of the charging semiconductor switch 5A, and the charging current flowing through the battery row 2A is cut off by the cutting-off operation of the charging semiconductor switch 5B. On the other hand, the discharge current from the battery row 1A is cut off by the cutting operation of the discharge semiconductor switch 6A, and the discharge current from the battery row 2A is cut off by the cutting operation of the discharge semiconductor switch 6B.

  The current generator 4 is connected in parallel to the series configuration of the battery array 1A and the first switch parallel configurations 5A and 6A and the series configuration of the battery array 2A and the first switch parallel configurations 5B and 6B. ing. The current generator 4 generates a constant current having a specified current value, and can flow the generated constant current to the battery row 1A and the battery row 2A in common. Here, the designated current value is variable.

  The charging control device 2 has a built-in charging circuit, and inputs a single voltage value of each secondary battery 1a, 1b,..., 1n detected by the battery monitoring device 3A and a column current value flowing through the battery column 1A. Then, the single voltage value of each secondary battery 2a, 2b,..., 2n detected by the battery monitoring device 3B and the column current value flowing through the battery column 2A are input.

  In addition, the charging control device 2 includes the single voltage values of the secondary batteries 1a, 1b,..., 1n transmitted from the battery monitoring device 3A and the secondary batteries 2a, 2b, transmitted from the battery monitoring device 3B. ..., 2n is used to control the current generated by the current generator 4 (that is, the specified current value) based on the single voltage value. Further, the charging control device 2 includes a single voltage value of each secondary battery 1a, 1b,..., 1n transmitted from the battery monitoring device 3A and each secondary battery 2a, 2b, transmitted from the battery monitoring device 3B. ..., 2n is controlled based on the single voltage value of 2n. The charging control device 2 also controls on / off of the discharging semiconductor switches 6A and 6B.

  Also in the present embodiment, the charging control device 2 performs the following control on the current generator 4 by utilizing the phenomenon (characteristic) of the secondary battery shown in FIG.

  That is, a control voltage value is set in advance in the charging control device 2. In the charge control device 2, the single voltage value of any of the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. Each time, the generated current (specified current value) of the current generator 4 is lowered step by step. That is, the charge control device 2 assumes that the single voltage value of any of the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. However, immediately, the generated current (specified current value) of the current generator 4 is not made zero, but the specified current value of the generated current is lowered stepwise and the constant current control is continued.

  In the charging control device 2, a protection voltage value higher than the control voltage value is also set in advance. In the charging control device 2, the single voltage value of any of the secondary batteries 1a, 1b, ..., 1n, 2a, 2b, ..., 2n constituting the battery group has reached the protection voltage value. Sometimes, the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. In order to cut off the charging current flowing through the battery arrays 1A and 2A, the charging control device 2 performs control to turn off one of the charging semiconductor switches 5A and 5B). The control for stopping the current flowing through the battery arrays 1A and 2A is stepwise even before the control for decreasing the generated current stepwise (that is, a state in which a constant current at an initial designated current value described later is flowing). Even during the control for reducing the generated current (ie, in a state where a constant current is supplied at each specified current value other than the initial specified current value), the control is performed.

  Here, the protection voltage values are the safety of the secondary batteries 1a, 1b, ..., 1n, 2a, 2b, ..., 2n and the secondary batteries 1a, 1b, ..., 1n, 2a, It is set from the viewpoint of preventing deterioration of 2b,. That is, when the battery voltage of the secondary batteries 1a, 1b, ..., 1n, 2a, 2b, ..., 2n exceeds the protection voltage value, the secondary batteries 1a, 1b, ..., 1n, 2a , 2b,..., 2n cannot be ensured, and the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. Further, the control voltage value is set slightly lower than the protection voltage value (for example, lower by about a few V).

  Next, the operation of the secondary battery charge control system 200 according to the second embodiment will be described.

  Charging the battery group (battery rows 1A and 2A) is started. That is, based on the command from the charge control device 2, the current generator 4 generates a constant current having an initial designated current value I1. The charging semiconductor switches 5A and 5B are both in the on state, and the generator 4 supplies the generated constant current to the battery rows 1A and 2A.

  The battery monitoring device 3A constantly detects the value of the current flowing through the battery row 1A, and the detection result is notified to the charging control device 2. Thereby, the charging control apparatus 2 can confirm that the constant current flowing through the battery array 1A is the initial designated current value I1. Similarly, the battery monitoring device 3B constantly detects the value of the current flowing through the battery row 2A, and the detection result is notified to the charging control device 2. Thereby, the charging control apparatus 2 can confirm that the constant current flowing through the battery array 2A is the initial designated current value I1.

  Further, the battery monitoring device 3A constantly detects the single voltage values of the secondary batteries 1a, 1b,..., 1n constituting the battery array 1A. Then, the battery monitoring device 3A notifies the charge control device 2 also of the detection result. Similarly, the battery monitoring device 3B always detects single voltage values of the secondary batteries 2a, 2b,..., 2n constituting the battery array 2A. Then, the battery monitoring device 3B notifies the charge control device 2 of the detection result.

  In the charging control device 2, the single voltage values of the secondary batteries 1a, 1b, ..., 1n, 2a, 2b, ..., 2n notified from the battery monitoring devices 3A, 3B, and the charging control device 2 A comparison is made with the control voltage value set in advance.

  As a result of the comparison, if any single voltage value of each of the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. Does not give a new command to the current generator 4. As a result, the current generator 4 continuously supplies a constant current having the initial designated current value I1 to the battery rows 1A and 2A.

  On the other hand, as a result of the comparison, the single voltage value has reached the control voltage value in any one of the secondary batteries 1a, 1b, ..., 1n, 2a, 2b, ..., 2n. Is determined by the charge control device 2. In this case, the charging control device 2 issues a new command to the current generator 4. Thereby, the current generator 4 lowers the generated current from the initial designated current value I1 to the designated current value I2, and continuously flows the constant current of the designated current value I2 to the battery rows 1A and 2A. Here, the initial specified current value I1> specified current value I2> 0.

  In this way, the secondary battery 1a, 1b,..., 1n, 2a, 2b,... Is reduced by reducing the charging current flowing through the battery rows 1A, 2A from the initial designated current value I1 to the designated current value I2.・ The battery voltage of 2n drops slightly. Therefore, even if the constant current having the specified current value I2 is continuously supplied to the battery rows 1A and 2A, the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. The voltage value does not immediately exceed the control voltage value, and a constant current having the specified current value I2 can be passed through the battery arrays 1A and 2A for a while. Therefore, the charge capacity in each secondary battery 1a, 1b, ..., 1n, 2a, 2b, ..., 2n can be continuously increased.

  As described above, the battery monitoring device 3A always detects the current value flowing through the battery row 1A, the battery monitoring device 3B constantly detects the current value flowing through the battery row 2A, and the detection results are as follows. The charging control device 2 is notified. Thereby, the charging control apparatus 2 can confirm that each constant current flowing through the battery row 1A and the battery row 2A has changed to the specified current value I2.

  Further, as described above, the battery monitoring device 3A constantly detects the single voltage values of the secondary batteries 1a, 1b,..., 1n constituting the battery array 1A. The battery monitoring device 3B always detects single voltage values of the secondary batteries 2a, 2b,..., 2n constituting the battery array 2A. Then, both the battery monitoring device 3A and the battery monitoring device 3B notify the charge control device 2 of the detection result of the single voltage value.

  In the charging control device 2, as described above, the single voltage values of the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. Comparison with a control voltage value set in advance in the charge control device 2 is performed.

  As a result of the comparison, if any single voltage value of each of the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. Does not give a new command to the current generator 4. As a result, the current generator 4 continuously supplies a constant current having the specified current value I2 to the battery rows 1A and 2A.

  On the other hand, as a result of the comparison, the single voltage value has reached the control voltage value in any one of the secondary batteries 1a, 1b, ..., 1n, 2a, 2b, ..., 2n. Is determined again by the charging control device 2. In this case, the charging control device 2 issues a new command to the current generator 4. As a result, the current generator 4 reduces the generated current from the specified current value I2 to the specified current value I3, and continuously supplies a constant current of the specified current value I3 to the battery rows 1A and 2A. Here, the specified current value I2> the specified current value I3> 0.

  In this way, the secondary batteries 1a, 1b,... 1n, 2a, 2b,. , 2n battery voltage drops slightly. Therefore, even if the constant current having the specified current value I3 is continuously supplied to the battery arrays 1A and 2A, the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. The voltage value does not immediately exceed the control voltage value, and a constant current having the specified current value I3 can be supplied to the battery arrays 1A and 2A for a while. Therefore, the charge capacity in each secondary battery 1a, 1b, ..., 1n, 2a, 2b, ..., 2n can be continuously increased.

  As described above, the charge control device 2 is configured such that the single voltage value becomes the control voltage value in any one of the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. Each time it reaches, the control to decrease the constant current generated by the current generator 4 stepwise is repeated.

  In the middle of passing the initial designated current value I1 to the battery rows 1A, 2A or passing the designated current values I2, I3, etc., which are lowered in stages, to the battery rows 1A, 2A. It is assumed that the charging control device 2 makes the following determination based on notifications from the battery monitoring devices 3A and 3B. That is, in the secondary batteries 1a, 1b,..., 1n, 2a, 2b,..., 2n constituting the battery group, the single voltage value becomes the protection voltage value set in advance in the charging control device 2. It is assumed that the charging control device 2 determines that it has been reached.

  As described above, the protection voltage value (> control voltage value) is set to ensure the safety of the secondary batteries 1a, 1b, ..., 1n, 2a, 2b, ..., 2n or the secondary batteries 1a, 1b,. .., 1n, 2a, 2b,..., 2n are selected according to the capacity performance of secondary batteries 1a, 1b,..., 1n, 2a, 2b,. Value. Therefore, if the single voltage of the secondary batteries 1a, 1b, ..., 1n, 2a, 2b, ..., 2n reaches the protection voltage value, the secondary batteries 1a, 1b, ..., 1n, 2a , 2b,..., 2n need to be stopped.

  Therefore, when the charging control device 2 determines that the single voltage value has reached the protection voltage value in the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. The charge control device 2 is connected in series to the battery rows 1A, 2A to which the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. A signal for turning off the switch state is transmitted to the semiconductor switches 5A and 5B.

  For example, it is assumed that the single voltage value of the secondary battery 1b has reached the protection voltage value. In this case, the charging control device 2 transmits a command to turn off the charging semiconductor switch 5A to the charging semiconductor switch 5A. In response to the command, the charging semiconductor switch 5A is turned off, and the charging current flowing through the battery array 1A to which the secondary battery 1b having reached the protection voltage value immediately stops (that is, all secondary batteries belonging to the battery array 1A). The charging of the batteries 1a, 1b, ..., 1n can be stopped). In each secondary battery 2a, 2b,..., 2n belonging to the battery array 2A, the single voltage value does not reach the protection voltage value, so that the charging current for the battery array 2A is continuously supplied.

  On the other hand, it is assumed that the single voltage value of the secondary battery 2n reaches the protection voltage value. In this case, the charging control device 2 transmits a command to turn off the charging semiconductor switch 5B to the charging semiconductor switch 5B. Upon receiving the command, the charging semiconductor switch 5B is turned off, and the charging current flowing through the battery array 2A to which the secondary battery 2n having reached the protection voltage value immediately stops (that is, all secondary batteries belonging to the battery array 2A). The charging of the batteries 2a, 2b, ..., 2n can be stopped). In each of the secondary batteries 1a, 1b,..., 1n belonging to the battery row 1A, the single voltage value does not reach the protection voltage value, so that the charging current for the battery row 1A is continuously supplied.

  Further, it is assumed that the single voltage values of the secondary battery 1a and the secondary battery 2b have reached the protection voltage value. In this case, the charging control device 2 transmits a command to turn off each of the charging semiconductor switch 5A and the charging semiconductor switch 5B to each of the charging semiconductor switches 5A and 5B. The charging semiconductor switches 5A and 5B that have received the command are turned off, and the charging current flowing through the battery row 1A to which the secondary battery 1a that has reached the protection voltage value and the battery row 2A to which the secondary battery 2b belongs is immediately stopped. (That is, charging of all secondary batteries 1a, 1b,..., 1n, 2a, 2b,..., 2n belonging to the battery arrays 1A, 2A can be stopped).

  As described above, in the secondary battery charge control system 200 according to the second embodiment, the charge control device 2 includes any one of the secondary batteries 1a, 1b,..., 1n, 2a, Each time the single voltage values of 2b,..., 2n reach the control voltage value, control is performed to reduce the current generated by the current generator 4 step by step.

  Therefore, even if the single voltage value of any of the secondary batteries 1a, 1b, ..., 1n, 2a, 2b, ..., 2n reaches the control voltage value, the charging current flowing through the battery group is immediately stopped. There is nothing. That is, although the specified current value is lowered, the charging current can continue to flow through the battery rows 1A and 2A. Even if the charging current is continued, the secondary batteries 1a, 1b,. .., 1n, 2a, 2b,..., 2n do not reach the control voltage value and reach a voltage that cannot guarantee safety or a voltage that deteriorates.

  Thus, in the present embodiment, even if the single voltage value of any of the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. The charging current flowing through the group can be continued (although the specified current value is gradually reduced). Therefore, the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. ., 1n, 2a, 2b,..., 2n can be charged in a state close to a fully charged state (that is, all secondary batteries 1a, 1b,. 2a, 2b,..., 2n can be increased.

  Moreover, in the secondary battery charge control system 200 according to the present embodiment, the charge control device 2 includes any of the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. .. When 2n reaches the protection voltage value, the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. Only for that, the charging current is stopped. Here, the protection voltage values are the security of the secondary batteries 1a, 1b, ..., 1n, 2a, 2b, ..., 2n and the secondary batteries 1a, 1b, ..., 1n, 2a. , 2b,..., 2n are values selected from the viewpoint of preventing deterioration (protection voltage value> control voltage value).

  Therefore, during the flow of charging current to the battery group, the single voltage of any of the secondary batteries 1a, 1b, ..., 1n, 2a, 2b, ..., 2n is protected for some reason. Even if the voltage value is reached, the battery rows 1A, 2A to which the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. Can be charged. Therefore, the secondary batteries 1a, 1b,..., 2n to which the secondary batteries 1a, 1b, ..., 1n, 2a, 2b,. ., 1n, 2a, 2b,..., 2n can be prevented, and as a result, the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. Safety can be ensured and the secondary batteries 1a, 1b,..., 1n, 2a, 2b,. The secondary batteries 1a, 1b,..., 1n, 2a, 2b,..., 2n that have reached the protection voltage value are continuously supplied with a charging current in the battery rows 1A, 2A. be able to.

  As described above, the number of battery rows connected in parallel may be three or more (a battery group is composed of all secondary batteries constituting all battery rows). In a configuration in which a plurality of battery rows are connected in parallel, a battery monitoring device that detects a column current and a single voltage value is provided for each battery row, and a switch parallel configuration (for charging) is connected in series to each battery row. A parallel configuration of a semiconductor switch and a discharging semiconductor switch). Then, the charging control device 2 receives the detection result from each battery monitoring device, and transmits a control signal to each switch parallel configuration and the current generator 4.

  Then, the charge control device 2 gradually increases the current generated by the current generator 4 every time the single voltage value of any of the secondary batteries constituting the battery group reaches a preset control voltage value. Control to lower. Furthermore, when the single voltage value of any secondary battery constituting the battery group reaches the protection voltage value, the charge control device 2 performs charging that flows to the battery row to which the secondary battery that has reached the protection voltage value belongs. The current is stopped, and the charging current is continuously supplied to the battery array in which there is no secondary battery that reaches the protection voltage value.

1a, 1b,..., 1n, 2a, 2b,..., 2n Secondary batteries 1A, 2A Battery array 2 Charge control device 3A, 3B Battery monitoring device 4 Current generator 5A, 5B Charging semiconductor switch 6A, 6B Semiconductor switch for discharging 100,200 Secondary battery charge control system

Claims (4)

A battery row in which at least two or more secondary batteries are connected in series;
A current generator for generating a current to flow through the battery array;
A control device for controlling the current generated by the current generator,
In the control device,
Control voltage value is set,
The controller is
Each time the single voltage value of any of the secondary batteries constituting the battery array reaches the control voltage value, the generated current of the current generator is lowered step by step.
A rechargeable battery charge control system. In the control device,
A protection voltage value higher than the control voltage value is set,
The controller is
When the single voltage value of any of the secondary batteries constituting the battery array reaches the protection voltage value, the current flowing through the battery array is stopped.
The secondary battery charge control system according to claim 1. A battery group in which at least two or more secondary batteries are connected in series, a battery group connected in parallel;
A current generator for generating a current to flow through the battery group;
A control device for controlling the current generated by the current generator,
In the control device,
Control voltage value is set,
The controller is
Each time the single voltage value of any of the secondary batteries constituting the battery group reaches the control voltage value, the generated current of the current generator is reduced stepwise.
A rechargeable battery charge control system. In the control device,
A protection voltage value higher than the control voltage value is set,
The controller is
When the single voltage value of any of the secondary batteries constituting the battery group reaches the protection voltage value, the current flowing through the battery array to which the secondary battery that has reached the protection voltage value belongs is stopped.
The secondary battery charge control system according to claim 3.

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