JP2009022099A - System and method for controlling battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system and a method for controlling a battery, which can prevent a battery or wiring from being damaged by an excessive current even in case that the discharge starting currents of a plurality of batteries connected in parallel are different. <P>SOLUTION: The battery controlling system is equipped with a first battery which outputs a discharge current to a load, a second battery which is connected in parallel with the first battery and outputs a discharge current smaller than that of the first battery to the load, a first discharge current measuring part which measures the discharge current of the first battery, a first upper-limit current storage part which stores the first upper-limit current value being the upper limit of the current to be outputted from the first battery to the load, and a first current controller which adjusts the discharge current from the first battery so that the discharge current from the first battery to the load, which is measured by the first discharge current measuring part, may be at or under the first upper-limit value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a battery management system and a battery management method, and more particularly to a battery management system and a battery management method for managing a plurality of batteries connected in parallel.

Until now, lead-acid batteries have been used as backup batteries for communication power supplies and the like. This lead storage battery has a large battery capacity and a large weight for taking out a certain amount of electricity. On the other hand, as a battery that can be replaced with such a lead storage battery, in recent years, lithium ion batteries have been developed, and examples of use as backups for communication power sources and the like have come to be seen.
When using an assembled battery consisting only of a lithium ion battery as a backup battery, the assembled battery may be used while maintaining the safety of the lithium ion battery.

  However, it may be necessary to add a backup battery to a battery management system that includes an assembled battery made of a conventional lead storage battery. In this case, a sufficient space may not be secured for the addition of the lead storage battery, and it is necessary to add a lithium ion battery assembly battery in parallel with the lead storage battery.

  By the way, a backup battery in a battery management system such as a communication power supply is installed in parallel with a load on the DC output side of the DC power supply, and the battery is used in a fully charged state by a floating charging method. Therefore, it is desired that the floating charging voltage of the backup battery used here is a value suitable for the DC output of the DC power supply. At the same time, this voltage value needs to be a voltage value suitable for maintaining the capacity of the backup battery for a long period of time.

  In the case of a lead-acid battery, when a voltage value such as 2.23 (V / cell) or 2.27 (V / cell) is selected and the lead-acid battery is connected in series to form an assembled battery, the voltage of the assembled battery Is a value obtained by multiplying the voltage described above by the number of single cells. For example, when 23 2.23 (V) lead-acid batteries are connected in series, 51.29 (V) is obtained, and when 24 2.23 (V) lead-acid batteries are connected in series, 53.V. 52 (V), and 54.48 (V) when 24 lead storage batteries of 2.27 (V) are connected in series.

  On the other hand, in the case of a lithium ion battery, 4.08 (V / cell) to 4.15 (V / cell) is used as a voltage suitable for long-term floating charging. Therefore, for example, if a lithium-ion battery is connected in parallel to an assembled battery (voltage = 53.52 (V)) in which, for example, 24 lead storage batteries of 2.23 (V / cell) are connected in series, long-term maintenance is maintained. The charging voltage suitable for the battery is 4.12 (V / cell), and the total battery voltage is 53.52 (V) by using an assembled battery consisting of 13 lithium-ion batteries. be able to. Thereby, the battery management system which connected two types of assembled batteries in parallel can be comprised.

  However, when a lead storage battery and a lithium ion battery are connected in parallel, the discharge current at the start of discharge tends to be biased toward the lithium ion battery in which the initial voltage is kept high. In some cases, a current exceeding the allowable value flows through the wiring of the lithium ion battery or the assembled battery, and the lithium ion battery main body or the wiring may be damaged.

  Control in a battery management system in which such a lead storage battery and a lithium ion battery are connected in parallel has also been conventionally performed. For example, the technique of Patent Document 1 relating to a battery management system for mounting on an automobile is known.

FIG. 9 is a configuration diagram of the battery management system 200 described in Patent Document 1. The battery management system 200 includes a motor generator 103, a load 108, and a battery management device 110. The battery management device 110 is connected between the motor generator 103 and the load 108.
The power management apparatus 110 includes a lead storage battery 101, a lithium ion battery 102, a shunt 104, a battery controller 105, a battery controller 106, and a current control controller 107.

  In this battery management system 200, a lead storage battery 101 and a lithium ion battery 102 are connected in parallel. When the lead storage battery 101 and the lithium ion battery 102 are charged by the power supplied from the motor generator 103, the voltage of the lead storage battery 101 is measured by the battery controller 105, and the voltage of the lithium ion battery 102 is measured by the battery controller 106. taking measurement. When the lithium ion battery 102 is charged to a predetermined voltage, the current controller 107 controls the shunt 104 to start charging the lead storage battery 101.

FIG. 10 shows the characteristics of the battery voltage and the discharge current as the discharge time elapses when an assembled battery in which a plurality of lead storage batteries are connected in series and an assembled battery in which a plurality of lithium ion batteries are connected in series are connected in parallel. FIG. In FIG. 10, the horizontal axis indicates the discharge time (h), the left side of the vertical axis indicates the battery voltage (V), and the right side of the vertical axis indicates the discharge current (A).
A graph g01 in FIG. 10 shows the relationship between discharge time and battery voltage in an assembled battery in which a plurality of lead storage batteries are connected in series. In the graph g01, the battery voltage decreases as the discharge time elapses.

Graph g02 shows the relationship between the discharge time and the battery voltage in an assembled battery in which a plurality of lithium ion batteries are connected in series. In the graph g02, the battery voltage decreases as the discharge time elapses.
Graph g03 shows the relationship between the discharge time and the discharge current in an assembled battery in which a plurality of lead storage batteries are connected in series. In the graph g03, the discharge current increases as the discharge time elapses.

Graph g04 shows the relationship between the discharge time and the discharge current in a battery pack in which a plurality of lithium ion batteries are connected in series. In the graph g04, the discharge current decreases as the discharge time elapses.
As shown in FIG. 10, when the discharge is started (discharge time is 0 (h)), the discharge current of the assembled battery of the lithium ion battery is large (see graph g04), and the discharge current of the assembled battery of the lead storage battery is small. (See graph g03).
Japanese Patent No. 3716776

  However, when a lead storage battery and a lithium ion battery are connected in parallel as in the prior art, the discharge proceeds at a bias toward the lithium ion battery in which the discharge current at the start of discharge is kept high. As a result, an excessive current flows in the wiring connected to the lithium ion battery, and the lithium ion battery and the wiring connected to the lithium ion battery may be damaged.

  The present invention has been made in view of the above circumstances, and the purpose of the present invention is to connect a battery or a wiring due to excessive current flowing even when the discharge start currents of a plurality of batteries connected in parallel are different. It is an object of the present invention to provide a battery management system and a battery management method that can prevent damage.

(1) The present invention has been made to solve the above problems, and a battery management system according to an aspect of the present invention includes a first battery that outputs a discharge current to a load, and a parallel connection with the first battery. A second battery that outputs a discharge current smaller than that of the first battery to the load, a first discharge current measurement unit that measures a discharge current of the first battery, and the first battery. To the load from the first battery measured by the first discharge current measuring unit and a first upper limit current value storage unit that stores a first upper limit current value that is an upper limit of the current output to the load from And a first current control unit that adjusts the discharge current from the first battery so that the discharge current is equal to or less than the first upper limit current value.

(2) Moreover, the battery management system by 1 aspect of this invention is the upper limit of the electric current output to the said load from the 2nd discharge current measurement part which measures the discharge current of a said 2nd battery, and a said 2nd battery. A second upper limit current value storage unit that stores the second upper limit current value, and a discharge current from the second battery to the load that is measured by the second discharge current measurement unit, A second current control unit that adjusts a discharge current from the second battery so as to be equal to or lower than an upper limit current value.

(3) In the battery management system according to one aspect of the present invention, the first upper limit current value is determined according to the magnitude of the current output from the first battery and the second battery to the load. A first upper limit current value determination unit is provided, and the first upper limit current value storage unit stores the first upper limit current value determined by the first upper limit current value determination unit.

(4) In the battery management system according to an aspect of the present invention, the second upper limit current value is determined according to the magnitude of the current output from the first battery and the second battery to the load. A second upper limit current value determination unit is provided, and the second upper limit current value storage unit stores the second upper limit current value determined by the second upper limit current value determination unit.

(5) Moreover, the first battery of the battery management system according to one aspect of the present invention is a lithium ion battery.

(6) Moreover, the said 2nd battery of the battery management system by 1 aspect of this invention is a lead acid battery.

(7) Further, the battery management method according to one aspect of the present invention includes a first battery that outputs a discharge current to a load, and a discharge current that is connected in parallel to the first battery and is smaller than the first battery. A battery management method for controlling a second battery to be output to the load by a battery management device including a first discharge current measuring unit and a first current control unit, wherein the discharge current of the first battery is The first step measured by the first discharge current measurement unit, and the discharge current from the first battery measured by the first discharge current measurement unit to the load is less than or equal to the first upper limit current value And a second step in which the first current controller adjusts the discharge current from the first battery.

  According to the battery management system and the battery management method of the present invention, even if the discharge start currents of a plurality of batteries connected in parallel are different, excessive current flows can damage the battery and wiring. Can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a first embodiment of the present invention will be described.

(First embodiment)
FIG. 1 is a block diagram showing a configuration of a battery management system 100a according to the first embodiment of the present invention. The battery management system 100a includes an assembled battery 1 (also referred to as a second battery), an assembled battery 2 (also referred to as a first battery), a DC power supply 3, a load 4, an AC power supply 5, and voltage adjustment circuits 7-1 to 7-7. -M (m is an integer of 2 or more), a control unit 8, discharge current setting units 9a and 9b, and a switch 10.
In the present embodiment, the voltage adjustment circuits 7-1 to 7-m (m is an integer of 2 or more), the control unit 8, the discharge current setting units 9a and 9b, and the switch 10 constitute a battery management device.

The assembled battery 1 is configured by connecting a plurality of secondary batteries 1-1 to 1-n (n is an integer of 2 or more) in series. Here, lead acid batteries are used as the secondary batteries 1-1 to 1-n. One terminal of the assembled battery 1 is connected to the discharge current setting unit 9a, and the other terminal is connected to the DC power source 3, the assembled battery 2, and the load 4.
The assembled battery 2 is configured by connecting a plurality of secondary batteries 2-1 to 2-m in series. Here, lithium ion batteries are used as the secondary batteries 2-1 to 2-m. One terminal of the assembled battery 2 is connected to the discharge current setting unit 9 b via the switch 10, and the other terminal is connected to the DC power supply 3, the assembled battery 1, and the load 4.

The direct current power source 3 converts the alternating current supplied from the alternating current power source 5 into a direct current and supplies the direct current to the assembled battery 1, the assembled battery 2, and the load 4. The load 4 drives the load using a direct current supplied from the assembled battery 1, the assembled battery 2, and the DC power supply 3.
The AC power source 5 is a commercial power source or the like, and supplies an AC current to the DC power source 3. The voltage adjustment circuits 7-1 to 7-m are connected in parallel to the secondary batteries 2-1 to 2-m, respectively.
The control unit 8 controls the opening / closing of the switch 10 by outputting a switch opening / closing signal to the switch 10 based on the signals output from the voltage adjustment circuits 7-1 to 7-m.

The discharge current setting unit 9 a is connected in series with the assembled battery 1 and controls the current output from the assembled battery 1 to the load 4. The discharge current setting unit 9b is connected in series with the assembled battery 2 and controls the current output from the assembled battery 2 to the load 4.
The switch 10 electrically connects or disconnects the assembled battery 2 and the discharge current setting unit 9b based on a switch opening / closing signal (switch opening signal, switch closing signal) output from the control unit 8.

FIG. 2 is a configuration diagram of the voltage adjustment circuit 7-1 (FIG. 1) according to the first embodiment of the present invention. The configuration of the voltage adjustment circuits 7-2 to 7-m is the same as that of the voltage adjustment circuit 7-1, and thus the description thereof is omitted.
The voltage adjustment circuit 7-1 includes a bypass current control element 71, a bypass current limiting element 72, a bypass current measuring element 73, a voltage error amplifier 74, and a voltage measuring error amplifier 75.
The bypass current control element 71, the bypass current limiting element 72, and the bypass current measuring element 73 are connected in series to constitute a bypass circuit. This bypass circuit is connected in parallel with the secondary battery 2-1.

The bypass current control element 71 is an element such as a transistor. When a control signal is received from the voltage error amplifier 74, the bypass current control element 71 bypasses a bypass current that is not used for charging the secondary battery 2-1 among the charging current. Control to flow.
The bypass current limiting element 72 is an element such as a fuse, and when a current larger than an allowable bypass current value that is the maximum value of the bypassable current flows in the bypass circuit, the bypass current control element 71 and the bypass current measuring element The electric current which flows between 73 is interrupted | blocked.
The bypass current measuring element 73 is an element such as a resistor, and measures the current value of the bypass current flowing through the bypass circuit and outputs the measured value to the control unit 8 (FIG. 1) as the bypass current measured value.

The voltage error amplifier 74 measures the reference voltage value V _b (for example, 4.10 (V)) output from the controller 8 and the battery voltage of the secondary battery 2-1 output from the voltage measurement error amplifier 75. When the value V _c is compared with the voltage V _c and the voltage V _c is greater than the voltage V _b , a control signal that instructs the bypass current control element 71 to flow a bypass current is output to the bypass current control element 71.
The voltage measurement error amplifier 75 calculates the voltage V _c of the secondary battery 2-1 from the difference between the voltage values of the input terminal and the output terminal of the secondary battery 2-1, and uses the voltage V _c as the control unit 8. Output to the voltage error amplifier 74.

Is output from the control unit 8, the reference voltage value V _b and the battery voltage measured value V _c, the control of the bypass current control element 71 of the bypass circuit by inputting the voltage error amplifier 74 is performed. If the bypass current control element 71 is completely turned on, the maximum allowable current flows as the bypass current. Further, if it is completely off, no bypass current flows. Furthermore, by using the bypass current control element 71 in the amplification region (unsaturated region), the state can be made the same as that of the variable resistor, and the current value of the bypass current to be bypassed can be continuously adjusted.

Thus, in this bypass circuit, the bypass current control element 71 can be used in the same manner as a variable resistor. Therefore, even when the voltage V _c approaches the set voltage V _b and the charging current becomes a minute value, Even a very small charging current can be bypassed. With such control, by continuously bypassing the charging current with the bypass circuit according to the terminal voltage value, each battery management device can be controlled so as not to exceed the voltage _Vb .

Returning to Figure 1, the control unit 8 is provided with a memory (not shown) stores a reference voltage value V _b for each of the secondary batteries 2-1 to 2-m that form the assembled battery 2. Here, the control unit 8 stores 4.10 (V) as the reference voltage value of each of the secondary batteries 2-1 to 2-m. The control unit 8 sets the reference voltage values of the secondary batteries 2-1 to 2-m to the voltages of the voltage adjustment circuits 7-1 to 7-m connected to the secondary batteries 2-1 to 2-m. The reference voltage value _Vb is output to the error amplifier 74 (see FIG. 2).
The control unit 8 is a battery voltage measured value _{V c} for each of the secondary batteries 2-1 to 2-m that form the assembled battery 2, and is connected to those of the secondary battery 2-1 to 2-m Received from the voltage measurement error amplifier 75 of the voltage adjustment circuits 7-1 to 7-m.
Further, the control unit 8 determines whether or not a power failure has occurred in the DC power supply 3 by measuring a DC current output from the DC power supply 3.

  In addition, the control unit 8 determines that the voltage of any of the secondary batteries 2-1 to 2-m constituting the assembled battery 2 exceeds a predetermined value (for example, 4.3 V) during charging. In the case where the voltage is lower than a predetermined value (for example, 3 V) at the time of discharging, a switch opening / closing signal for opening the switch 10 is applied to the switch 10 from the viewpoint of protecting the secondary batteries 2-1 to 2-m. Output.

  FIG. 3 is a configuration diagram of the discharge current setting unit 9a (FIG. 1) according to the first embodiment of the present invention. The discharge current setting unit 9a includes a discharge current control element 91 (also referred to as a first current control unit and a second current control unit) and a discharge current detection element 92 (a first discharge current measurement unit and a second discharge current). A discharge current control error amplifier 93, a discharge current measurement error amplifier 94, and a microcontroller 99 (also referred to as a first upper limit current value storage unit and a second upper limit current value storage unit). .

The microcontroller 99 stores an upper limit current value that is the upper limit of the current value of the current output from the assembled battery 2 to the load 4. This upper limit current value is recorded in advance in the microcontroller 99 by the administrator of the battery management system according to the present embodiment. The microcontroller 99 outputs an upper limit current value to the discharge current control error amplifier 93.
The discharge current control element 91 is an element such as a transistor, and the current value of the inflow current flowing from the assembled battery 2 exceeds the upper limit current value based on the signal output from the discharge current control error amplifier 93. In this case, the current value of the inflow current is reduced to the upper limit current value and output to the load 4.

The discharge current detecting element 92 is an element such as a resistor, measures the current value of the inflow current flowing from the assembled battery 2 into the discharge current setting unit 9a, and outputs the current value to the discharge current measuring error amplifier 94. The discharge current control error amplifier 93 determines whether or not the current value output from the discharge current measurement error amplifier 94 is larger than the upper limit current value output from the microcomputer 99.
When it is determined that the current value output from the discharge current measurement error amplifier 94 is larger than the upper limit current value output from the microcomputer 99, the discharge current control error amplifier 93 receives the discharge current from the assembled battery 2. A control signal for reducing the current value of the inflow current flowing into the setting unit 9 a to the upper limit current value is output to the discharge current control element 91.
The discharge current measuring error amplifier 94 measures the current value flowing through the discharge current detecting element 92 and outputs the current value to the discharge current control error amplifier 93.

  In addition, although FIG. 3 mentioned above demonstrated the structure of the discharge current setting part 9a, since it is the same as that of the discharge current setting part 9a also about the structure of the discharge current setting part 9b (FIG. 1), the description is abbreviate | omitted. The discharge current setting unit 9b and the discharge current setting unit 9a have different upper limit current values stored in the microcomputer 99. For example, the microcomputer 99 of the discharge current setting unit 9a stores 50 (A) as the upper limit current value, and the microcomputer 99 of the discharge current setting unit 9b stores 20 (A) as the upper limit current value.

  In the first embodiment of the present invention, at the start of discharge, the battery pack 2 composed of the lithium ion batteries 2-1 to 2-m is discharged more excessively than the battery pack 1 composed of the lead storage batteries 1-1 to 1-n. Even when a current is output to the load 4, a current obtained by reducing the discharge current output from the assembled battery 2 to the upper limit current value set by the discharge current setting unit 9 b in the microcontroller 99 is supplied to the load 4. Output. Thereby, even when the discharge current at the start of discharge of any one of the plurality of assembled batteries connected in parallel is large, the discharge current output from the assembled battery is reduced to the upper limit current value. Therefore, it is possible to prevent damage caused by an overcurrent flowing through the assembled battery and the wiring connected to the assembled battery.

(Second Embodiment)
FIG. 4 is a block diagram showing a configuration of a battery management system 100b according to the second embodiment of the present invention. This battery management system 100b includes an assembled battery 1, an assembled battery 21, 22, a DC power source 3, a load 4, an AC power source 5, a control unit 6, discharge current setting units 9c, 9d, 9e, discharge current measuring units 11a, 11b, 11c and 11d.
In the present embodiment, the control unit 6, the discharge current setting units 9c, 9d, and 9e, and the discharge current measurement units 11a, 11b, 11c, and 11d constitute a battery management device.
In addition, about 2nd Embodiment, the description is abbreviate | omitted about the part similar to 1st Embodiment. Here, a case where the assembled battery 21 and the assembled battery 22 are added to the assembled battery 1 will be described.

  The assembled battery 1 is configured by connecting a plurality of secondary batteries 1-1 to 1-n in series. Here, lead acid batteries are used as the secondary batteries 1-1 to 1-n. One terminal of the assembled battery 1 is connected to the discharge current setting unit 9c, and the other terminal is connected to the DC power source 3, the assembled batteries 21, 22 and the load 4.

  The assembled battery 21 is configured by connecting a plurality of secondary batteries 21-1 to 21-m in series. Here, lithium ion batteries are used as the secondary batteries 21-1 to 21-m. One terminal of the assembled battery 21 is connected to the discharge current setting unit 9 b, and the other terminal is connected to the DC power source 3, the assembled battery 1, the assembled battery 22, and the load 4.

  The assembled battery 22 is configured by connecting a plurality of secondary batteries 22-1 to 22-m in series. Here, lithium ion batteries are used as the secondary batteries 22-1 to 22-m. One terminal of the assembled battery 22 is connected to the discharge current setting unit 9 c, and the other terminal is connected to the DC power source 3, the assembled battery 1, the assembled battery 21, and the load 4.

The direct current power source 3 converts the alternating current supplied from the alternating current power source 5 into a direct current and supplies the direct current to the assembled battery 1, the assembled batteries 21 and 22, and the load 4. The load 4 drives the load using a direct current supplied from the assembled battery 1, the assembled batteries 21 and 22, and the DC power supply 3.
The control unit 6 updates the upper limit current value stored in the microcomputer included in the discharge current setting units 9c to 9e based on the current value output from the discharge current measuring units 11a to 11d.

  The discharge current setting unit 9 c is connected in series with the assembled battery 1 and controls the current output from the assembled battery 1 to the load 4. The discharge current setting unit 9d is connected in series with the assembled battery 21 and controls the current output from the assembled battery 21 to the load 4. The discharge current setting unit 9e is connected in series with the assembled battery 22 and controls the current output from the assembled battery 22 to the load 4.

The discharge current measuring unit 11 a measures the discharge current output to the load 4 by the discharge current setting unit 9 c and outputs the measured discharge current to the control unit 6. The discharge current measuring unit 11 b measures the discharge current output to the load 4 by the discharge current setting unit 9 d and outputs the measured discharge current to the control unit 6.
Further, the discharge current measuring unit 11 c measures the discharge current output to the load 4 by the discharge current setting unit 9 e and outputs the measured discharge current to the control unit 6. The discharge current measuring unit 11 d measures the load current output to the load 4 by the DC power supply 3 and the discharge current setting units 9 c to 9 e and outputs the load current to the control unit 6.

  FIG. 5 is a configuration diagram of the control unit 6 (FIG. 4) according to the second embodiment of the present invention. The control unit 6 includes a set value input unit 61, a storage unit 62, a power failure signal input unit 63, a calculation unit 64 (also referred to as a first upper limit current value determination unit and a second upper limit current value determination unit), and a discharge current measurement. A value input unit 65 and an upper limit current value transmission unit 66 are provided.

The set value input unit 61 includes an input device such as a keyboard, acquires battery information related to the battery management system 100b, and records it in the storage unit 62.
The storage unit 62 includes a memory and stores battery information input to the set value input unit 61.

FIG. 6 is a diagram illustrating an example of battery information stored in the storage unit 62 (FIG. 5) according to the second embodiment of the present invention. The storage unit 62 stores the capacity (500 (Ah)), load current (50 (A)), and discharge duration (10 (h)) of the battery 1 before adding the assembled batteries (assembled batteries 21 and 22). is doing. Moreover, the memory | storage part 62 has memorize | stored the load current (100 (A)) at the time of battery addition.
In addition, the storage unit 62 includes a battery capacity (500 (Ah)), a load current sharing (50 (A)), a discharge duration (10 (A)), a battery pack of the battery pack 1 including the lead storage battery after the addition of the battery. Maximum discharge current setting value of battery (50 (A)), discharge current when discharge current is 50 (A) (0 (A)), discharge current when discharge current is 80 (A) (30 (A)) ), The discharge current (50 (A)) when the discharge current is 100 (A) is stored.

  In addition, the storage unit 62 includes an additional battery capacity (200 (Ah)) of the assembled battery 21 including a lithium ion battery after the addition of batteries, a battery capacity after the addition (200 (Ah)), and a sharing of load current (20 (A). )), Discharge duration (10 (A)), maximum discharge current set value of assembled battery (20 (A)), discharge current (20 (A)) when discharge current is 50 (A), discharge current The discharge current (20 (A)) at 80 (A) and the discharge current (20 (A)) at 100 (A) are stored.

  In addition, the storage unit 62 includes an additional battery capacity (300 (Ah)) of the assembled battery 22 including a lithium ion battery after the addition of the battery, a battery capacity after the addition (300 (Ah)), and a sharing of the load current (30 (A). )), Discharge duration (10 (h)), maximum discharge current set value (30 (A)) of the assembled battery, discharge current (30 (A)) when the discharge current is 50 (A), discharge current The discharge current (30 (A)) at 80 (A) and the discharge current (30 (A)) at 100 (A) are stored.

Returning to FIG. 5, when the DC current output from the DC power supply 3 becomes 0 (A), the power failure signal input unit 63 receives a power failure occurrence detection signal from the DC power supply 3 and sends the signal to the calculation unit 64. Output.
The calculation unit 64 performs calculation based on the battery information (FIG. 5) stored in the storage unit 62, the signal output from the power failure signal input unit 63, and the signal output from the discharge current measurement value input unit 65. The upper limit current value that is the result of the calculation is output to the upper limit current value transmission unit 66. The calculation by the calculation unit 64 will be described later.

The discharge current measurement value input unit 65 receives the discharge current measurement values of the assembled batteries 1, 2, and 22 from the discharge current measurement units 11 a to 11 c and outputs them to the calculation unit 64. The discharge current measurement value input unit 65 receives the load current measurement value from the discharge current measurement unit 11 d and outputs the load current measurement value to the calculation unit 64.
The upper limit current value transmission unit 66 transmits the upper limit current value, which is the calculation result of the calculation unit 64, to each of the discharge current setting units 9c to 9e, whereby the microcontroller 99 provided in the current setting units 9c to 9e (FIG. 3). Record the upper limit current value.

FIG. 7 is a flowchart showing the processing of the control unit 6 according to the second embodiment of the present invention.
First, the set value input unit 61 receives input of battery information (step S101). This battery information is input to the set value input unit 61 based on the operation of the administrator of the battery management system 100b.
The battery information includes the number of parallel assembled batteries (1 (column) in FIG. 6), the capacity of each assembled battery (500 (Ah) in FIG. 6), and the maximum discharge current of each assembled battery (FIG. 6). Then, information such as 50 (A)) is included. The battery information includes the number of parallel assembled batteries of lithium-ion batteries (2 (column) in FIG. 6), the capacity of each assembled battery (200 (Ah) and 300 (Ah) in FIG. 6), Information such as the assembled battery maximum discharge current (20 (A) and 30 (A) in FIG. 6) is included.

Next, it waits for a predetermined time (for example, 1 (second)) (step S102). Then, based on whether or not a power failure occurrence detection signal is input to the power failure signal input unit 63, the calculation unit 64 determines whether or not a power failure has occurred (step S103).
If no power failure has occurred, the operation unit 64 determines “NO” in step S103, and proceeds to step S102. On the other hand, if a power failure occurs, the calculation unit 64 determines “YES” in step S103, and the process proceeds to step S104.

Then, the discharge current measurement value input unit 65 performs current measurement (step S104). Specifically, the discharge current measurement value input unit 65 performs current measurement by receiving the current values measured by the discharge current measurement units 11a to 11d.
And the calculating part 64 determines whether load current is below the sharing current of the assembled battery consisting of a lithium ion battery (step S105). That is, the load current is the shared current of the assembled batteries 21 and 22 made of a lithium ion battery (in FIG. 6, the shared current of the assembled battery 21 (20 (A)) and the shared current of the assembled battery 22 (30). The arithmetic unit 64 determines whether or not the total value of (A)) is 50 (A)) or less.

When the load current is equal to or less than the battery pack sharing current made of the lithium ion battery, the calculation unit 64 determines “YES” in step S105, and the process proceeds to step S106.
Then, the number of assembled batteries of lithium ion batteries (here, the assembled battery 21 and the assembled battery 22) and the capacity (the battery capacity (200 (Ah) of the assembled battery 21) and the battery capacity (300 (Ah) of the assembled battery 22 ))) To distribute the current and discharge (step S106) For example, when the load current is I (A), the lithium ion battery 21 has (I (A) × 200 (Ah)). / (200 (Ah) +300 (Ah)) = 2I / 5 (A) is set as the upper limit current value, and the lithium ion battery 22 has (I (A) × 300 (Ah)) / (200 (Ah). ) +300 (Ah)) = 3I / 5 (A) is the upper limit current value.

The upper limit current value transmission unit 66 transmits the upper limit current value of the assembled battery 21 to the discharge current setting unit 9d, and records the upper limit current value in the microcontroller 99 of the discharge current setting unit 9d. The upper limit current value transmitting unit 66 transmits the upper limit current value of the assembled battery 22 to the discharge current setting unit 9e, and records the upper limit current value in the microcontroller 99 of the discharge current setting unit 9e.
In step S106, the assembled battery 1 made of a lead storage battery is not discharged.

On the other hand, when the load current is larger than the battery pack sharing current made of the lithium ion battery, the operation unit 64 determines “NO” in step S105, and the process proceeds to step S107.
Then, the assembled batteries 21 and 22 made of lithium ion batteries are discharged at the maximum discharge current (step S107). Here, since the maximum discharge current set value of the lithium ion battery 21 is set to 20 (A) as shown in FIG. 6, the lithium ion battery 21 is discharged at 20 (A).
Moreover, since the maximum discharge current set value of the lithium ion battery 22 is set to 30 (A) as shown in FIG. 6, the lithium ion battery 22 is discharged at 30 (A).

Then, based on the information stored in the storage unit 62 (FIG. 6), the calculation unit 64 determines whether or not the number of assembled batteries of the lead storage battery is plural (step S108). Here, since the assembled battery consisting of the lead storage battery is only the assembled battery 1 and the number of assembled batteries is one, “NO” is determined in Step S108, and the process proceeds to Step S110.
And the electric current exceeding the discharge amount of the assembled batteries 21 and 22 which consist of lithium ion batteries is discharged from the assembled battery which consists of lead acid batteries (step S110).

On the other hand, when the number of assembled batteries of the lead storage battery is plural, “YES” is determined in the step S108, and the process proceeds to the step S109.
Then, depending on the number and capacity of the assembled batteries of the lead storage battery, the discharge currents of the assembled batteries 21 and 22 made of lithium ion batteries (here, the discharge current 20 (A) of the assembled battery 21 and the discharge current 30 of the assembled battery 22). A current exceeding the total value 50 (A) of (A) is distributed and discharged (step S109).
Here, since the number of assembled batteries made of lead-acid batteries is 1, the discharge current 50 (A) is discharged from the assembled battery 1 without allocating the discharge current 50 (A).
The discharge current value determined in step S109 is transmitted as an upper limit current value to the discharge current setting unit 9c connected to the lead storage battery 1, and the upper limit current value is recorded in the microcontroller 99 of the discharge current setting unit 9c.

Then, based on whether or not the input of the power failure occurrence detection signal to the power failure signal input unit 63 has stopped, the arithmetic unit 64 determines whether or not the power failure has ended (step S111).
If the power failure has not ended, the calculation unit 64 determines “NO” in step S111 and proceeds to step S104. On the other hand, when the power failure ends, the calculation unit 64 determines “YES” in step S111 and proceeds to step S102.

  According to the second embodiment of the present invention, the currents output from the respective assembled batteries 1, 22 and 22 to the load 4 in accordance with the load currents which are currents output from the assembled batteries 1, 22 and 22 to the load 4 Since the value is recorded as the upper limit current value in the microcontroller 99 of the discharge current setting units 11c, 11d, and 11e, a current larger than the upper limit current value is obtained from each of the assembled batteries 1, 2, and 22 according to the load current. The load 4 is not supplied. Therefore, it is possible to prevent the assembled batteries 21 and 22 and the wiring connected to the assembled batteries 21 and 22 from being damaged by an excessive current flowing through the wiring connected to the assembled batteries 21 and 22.

  In the second embodiment, the case where information as shown in FIG. 6 is recorded in the storage unit 62 of the control unit 6 has been described. However, the present invention is not limited to this. For example, information as shown in FIG. 8 may be recorded.

  FIG. 8 is a diagram showing another example of battery information stored in the storage unit 62 (FIG. 5) according to the second embodiment of the present invention. Here, the case where the assembled battery which consists of one lithium ion battery is added to the two assembled batteries connected in parallel which consist of lead acid batteries is demonstrated.

The storage unit 62 includes capacity (500 (Ah), 500 (Ah)), load current (50 (A), 50 (A)), discharge duration (10) before adding lithium ion batteries. (H), 10 (h)) are stored.
Moreover, the memory | storage part 62 has memorize | stored the load current (150 (A)) at the time of battery addition.
Moreover, the memory | storage part 62 is the battery capacity (500 (Ah), 500 (Ah)) of the assembled battery 1 which consists of lead acid batteries after battery addition, load current sharing (50 (A), 50 (A)), discharge Duration (10 (A), 10 (A)), battery pack maximum discharge current setting value (50 (A), 50 (A)), discharge current when discharge current is 50 (A) (0 (A ), 0 (A)), discharge current when the discharge current is 120 (A) (35 (A), 35 (A)), discharge current when the discharge current is 140 (A) (45 (A), 45 (A)), the discharge current (50 (A), 50 (A)) when the discharge current is 150 (A) is stored.

  In addition, the storage unit 62 includes an additional battery capacity (500 (Ah)) of an assembled battery including a lithium-ion battery after the addition of the battery, a battery capacity (500 (Ah)) after the addition, and a load current sharing (50 (A)). ), Discharge duration (10 (h)), maximum discharge current set value (50 (A)) of the assembled battery, discharge current (50 (A)) when the discharge current is 50 (A), discharge current is 120 The discharge current (50 (A)) when (A), the discharge current (50 (A)) when the discharge current is 140 (A), the discharge current (150 (A) when the discharge current is 150 (A) )) Is remembered.

  Even when information as shown in FIG. 8 is stored in the storage unit 62 of the control unit 6, the processing of the flowchart shown in FIG. 7 is performed by using the configuration of the battery management system shown in FIG. The same effect as that of the second embodiment can be obtained.

In addition, although embodiment mentioned above demonstrated the case where the some assembled battery was connected in parallel, it is not limited to this. For example, the first or second embodiment of the present invention may be applied to a battery management system in which one secondary battery is connected in parallel instead of an assembled battery in which secondary batteries are connected in series.
Moreover, although embodiment mentioned above demonstrated the case where different assembled batteries, ie, the assembled battery which consists of lead acid batteries, and the assembled battery which consists of lithium ion batteries were connected in parallel, it is not limited to this. For example, you may apply the 1st or 2nd embodiment of this invention to the battery management system which connected the assembled battery which consists of a secondary battery of the same kind in parallel.
Moreover, although embodiment mentioned above demonstrated the case where a lead storage battery or a lithium ion battery was used as a secondary battery, it is not limited to this, Secondary batteries other than a lead storage battery or a lithium ion battery are used as a secondary battery. A battery may be used or a primary battery may be used.

  In the embodiment described above, a program for realizing the function of each unit of the battery management system 100a in FIG. 1 or each unit of the battery management system 100b in FIG. 4 is recorded on a computer-readable recording medium. The battery management systems 100a and 100b may be controlled by causing a computer system to read and execute a program recorded on a recording medium. Here, the “computer system” includes an OS and hardware such as peripheral devices.

  The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” dynamically holds a program for a short time, like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, it is also assumed that a server that holds a program for a certain time, such as a volatile memory inside a computer system that serves as a server or client. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the design and the like within the scope of the present invention are also within the scope of the claims. include.

It is a block diagram which shows the structure of the battery management system 100a by the 1st Embodiment of this invention. It is a block diagram of the voltage adjustment circuit 7-1 (FIG. 1) by the 1st Embodiment of this invention. It is a block diagram of the discharge current setting part 9a (FIG. 1) by the 1st Embodiment of this invention. It is a block diagram which shows the structure of the battery management system 100b by the 2nd Embodiment of this invention. It is a block diagram of the control part 6 (FIG. 4) by the 2nd Embodiment of this invention. It is a figure which shows an example of the battery information which the memory | storage part 62 (FIG. 5) by the 2nd Embodiment of this invention memorize | stores. It is a flowchart which shows the process of the control part 6 by the 2nd Embodiment of this invention. It is a figure which shows another example of the battery information which the memory | storage part 62 (FIG. 5) by the 2nd Embodiment of this invention memorize | stores. 1 is a configuration diagram of a battery management system described in Patent Document 1. FIG. It is a figure which shows the characteristic of the battery voltage and discharge current with progress of discharge time at the time of connecting the assembled battery which connected the some lead acid battery in series, and the assembled battery which connected the some lithium ion battery in series. .

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Assembly battery, 1-1 to 1-n ... Secondary battery, 2 ... Assembly battery, 2-1 to 2-m ... Secondary battery, 3 ... DC power supply, 4 ... Load, 5 ... AC power supply, 6 ... Control unit, 7-1 to 7-m ... Voltage adjustment circuit, 8 ... Control unit, 9a-9e ... Discharge current setting unit DESCRIPTION OF SYMBOLS 10 ... Switch, 11a-11d ... Discharge current measurement part, 21, 22 ... Battery assembly, 61 ... Setting value input part, 62 ... Memory | storage part, 63 ... Power failure signal input 64, calculation unit, 65 ... discharge current measurement value input unit, 66 ... upper limit current value transmission unit, 71 ... bypass current control element, 72 ... bypass current limiting element, 73. .... Bypass current measuring element, 74 ... Voltage error amplifier, 75 ... Voltage measuring error amplifier, 91 ... Discharge current control element, 92 ... Discharge current Detecting element, 93 ... discharge current control error amplifier, 94 ... discharge current measurement error amplifier, 99 ... microcontroller, 100a, 100b ... battery management system

Claims (7)

A first battery that outputs a discharge current to a load;
A second battery connected in parallel with the first battery and outputting a discharge current smaller than that of the first battery to the load;
A first discharge current measuring unit for measuring a discharge current of the first battery;
A first upper limit current value storage unit that stores a first upper limit current value that is an upper limit of a current output from the first battery to the load;
First adjusting the discharge current from the first battery so that the discharge current from the first battery to the load measured by the first discharge current measuring unit is less than or equal to the first upper limit current value. 1 current control unit;
A battery management system comprising: A second discharge current measuring unit for measuring a discharge current of the second battery;
A second upper limit current value storage unit that stores a second upper limit current value that is an upper limit of the current output from the second battery to the load;
Adjusting the discharge current from the second battery so that the discharge current from the second battery to the load measured by the second discharge current measuring unit is less than or equal to the second upper limit current value; Two current control units;
The battery management system according to claim 1, further comprising: A first upper limit current value determining unit that determines the first upper limit current value according to the magnitude of the current output from the first battery and the second battery to the load;
The battery management system according to claim 1, wherein the first upper limit current value storage unit stores a first upper limit current value determined by the first upper limit current value determination unit. A second upper limit current value determining unit that determines the second upper limit current value according to the magnitude of the current output from the first battery and the second battery to the load;
The said 2nd upper limit electric current value memory | storage part memorize | stores the 2nd upper limit electric current value which the said 2nd upper limit electric current value determination part determined, The one in any one of Claim 1 to 3 characterized by the above-mentioned. Battery management system.   The battery management system according to any one of claims 1 to 4, wherein the first battery is a lithium ion battery.   The battery management system according to any one of claims 1 to 5, wherein the second battery is a lead storage battery. A first battery that outputs a discharge current to a load;
A second battery connected in parallel with the first battery and outputting a discharge current smaller than that of the first battery to the load;
A battery management method controlled by a battery management device comprising a first discharge current measuring unit and a first current control unit,
A first step in which the first discharge current measuring unit measures the discharge current of the first battery;
The discharge current from the first battery is measured so that the discharge current from the first battery to the load measured by the first discharge current measuring unit is not more than the first upper limit current value. A second step adjusted by the current controller of
The battery management method characterized by performing.

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