JP5033562B2 - Storage battery storage device and storage battery storage method - Google Patents

Description

  The present invention relates to a storage or inspection device for a rechargeable storage battery such as a lithium secondary battery, a nickel metal hydride battery, a lead battery, and an electric double layer capacitor.

  In recent years, secondary batteries such as lead batteries, nickel metal hydride batteries, lithium secondary batteries, and capacitors are generally mounted as driving batteries for electric vehicles and hybrid vehicles. In particular, nickel-metal hydride batteries and lithium secondary batteries have higher energy density than lead-acid batteries. Therefore, they have a multi-series / multi-parallel configuration, mainly for electric vehicles, hybrid cars, commuter cars, hybrid railways, etc. Used as a power storage system. In particular, a large-scale battery system that requires high voltage and large current has a configuration in which a plurality of storage batteries are connected in series.

  Here, the definition of the storage battery in the present invention will be described. In a power storage device that can be repeatedly charged and discharged, a minimum power storage element composed of a pair of positive and negative electrodes is a single cell. A unit in which a plurality of unit cells are connected in series to form an assembled battery, or a configuration in which a plurality of these units are connected, and in appearance, in a single block shape or a shape accommodated in a housing, a set of positive terminal and negative electrode A module having a current input / output path at a terminal is defined as a storage battery in a narrow sense.

  When the secondary battery is repeatedly charged and discharged, the state of charge (SOC) and the state of health (SOH) change, and as the deterioration progresses, the charge / discharge capacity decreases and the internal resistance of the battery decreases. Cause an increase. Therefore, the output of the system gradually decreases with deterioration. It is well known that deterioration due to self-discharge proceeds during storage and there is a voltage drop. Capacitors have a large voltage fluctuation and self-discharge due to their structure, apart from deterioration. In addition, due to an unpredictable abnormality caused by a cause at the time of manufacture of a part of secondary batteries connected in multiple series or other parallel, the battery voltage may drop, and in the worst case, charging / discharging may not be possible.

  Self-discharge during storage of the storage battery will be described in detail with reference to FIG. In the case of only a self-discharge caused by a chemical reaction inside the battery in a single cell, the voltage changes in the locus of FIG. 3a in which the storage time from the storage start voltage Vh to a certain threshold voltage Vth becomes t4. . However, when unit cells are assembled, a plurality of unit cells are unitized together with a control circuit such as voltage monitoring. In this case, when the current supply to the control circuit is stored without being completely cut off, the voltage of the storage battery takes the locus of FIG. 3b, the voltage drops, and overdischarge is not permitted to use the storage battery at time t3. The voltage becomes VL or less in the region. In addition, if the storage battery is defective due to a structural failure, such as a micro short-circuit inside, or the current consumption is large due to a defective control circuit, the speed of this voltage drop increases, and as shown in FIG. It reaches the discharge area. A storage battery that reaches the overdischarged region loses its function and cannot be recharged, which is a problem.

  So far, the single cell itself, particularly the lithium ion battery, has little deterioration in self-discharge, so that special measures such as supplementary charging have not been necessary when left alone. However, Patent Document 1 describes a method for storing a lithium secondary battery for suppressing deterioration over a longer period.

  In Patent Document 1, as a method for storing a lithium secondary battery that suppresses capacity deterioration, a process of supplying and discharging a low current value of 0.5 to 0.01 CA and a process of discharging to a predetermined voltage are alternately repeated. Therefore, it is said that the self-discharge speed when the unit cell is left can be suppressed.

JP 2000-113909 A

  Conventionally, a storage battery has rarely been incorporated into a battery system after a long period of several months from shipment. Furthermore, the number of storage batteries used in one battery system to which the storage battery is applied may be as small as 1 or 2 when the largest storage battery means is considered as one unit in a hybrid vehicle, for example, and the storage period of the storage battery is short. It was rare to reach the overdischarge region. In the future, it is expected that a battery system with a larger capacity will be required, and such a large-scale battery system has many manufacturing processes in order to connect a large number of large storage batteries. Storage batteries tend to be stored for a long time as a large number of stocks at the time of manufacture or replacement, and the period until they are incorporated into a battery system becomes longer. For this reason, there is a possibility that the self-discharge at the time of leaving the battery becomes an overdischarged state and cannot be used as a storage battery. In particular, in an assembled battery, energy is consumed by a built-in circuit in addition to self-discharge based on a chemical or physical reaction of a single battery storage battery. The storage battery consumed by the built-in circuit needs to be charged several times during the storage period of the storage battery even in the case of a lithium ion battery with little self-discharge for the purpose of preventing an overdischarge state.

  When the power storage system becomes large-scale, a large storage battery is required, and in using a plurality of storage batteries in series and parallel connection, it is important to match the performance of the storage batteries as much as possible in order to use the storage batteries effectively for a long period of time. Furthermore, a large-scale battery system needs to connect a plurality of large-sized storage batteries in series and in parallel. The performance of such a large-scale battery system is determined by the storage battery having the lowest performance in the battery system. Therefore, in order to use the battery system effectively for a long period of time, it is necessary to construct a battery system using storage batteries having the same performance as possible. Furthermore, in a multi-parallel system, it is necessary to reduce the voltage difference between the storage batteries in order to reduce the cross current flowing between the storage batteries during parallel connection and to suppress heat generation.

  However, when storing by the technique described in Patent Document 1 described above, since a small current of 0.5 CA to 0.01 CA is used before storing the battery, it takes time to charge and discharge, and a large amount of storage battery is charged and discharged. It takes too long to complete. Further, secondary batteries for hybrid use, particularly lithium batteries and capacitors, are not appropriate methods, and show a charge / discharge method before storage rather than a storage device. When storing multiple storage batteries, it is possible to adjust the voltage of a single storage battery (including a single battery), but the capacity and resistance of multiple storage batteries cannot be confirmed and the history is unknown. The procedure for controlling the voltage so as not to be overdischarged due to self-discharge during storage until it is assembled into the battery and further adjusting the voltage to unify the characteristics of the storage battery within a certain range is complicated. In addition, in order to charge and discharge a large number of storage batteries at once, a large-capacity power supply device is required, and a high-performance automatic charge / discharge device is expensive and large in size, making it difficult to introduce the device.

  The present invention has been developed for the purpose of solving the conventional drawbacks described above, and prevents overdischarge of a plurality of storage batteries during the storage period of the storage batteries, and improves the quality of the plurality of storage batteries. The purpose is to detect.

The present invention includes at least a power source for charging / discharging a storage battery, a voltage detection unit for detecting a voltage of the storage battery, a data recording unit for recording a detection voltage of the voltage detection unit, and the voltage information recorded in the data recording unit. possess a quality determining acceptability determining function unit of quality, such storage operation, the slope of the voltage drop of the battery, the voltage of the current of the storage battery, the first threshold voltage for the charging start determination The above-mentioned problem is solved by a storage battery storage device that is repeatedly performed at a time interval required by the above. The power source described in the claims broadly means a means capable of charging at least the storage battery. Specifically, the charging / discharging means, the charging power source, the constant voltage power source, the constant current power source, the power storage means, Generators, fuel cells, commercial systems, etc. Here, the storage battery described in the claims is a unit in which a plurality of unit cells as described above are connected in series to form an assembled battery, or a configuration in which a plurality of such units are connected, and has a single block shape or housing in appearance. It is not a narrowly-defined storage battery intended only for a module having a current input / output path with a pair of positive electrode terminals and negative electrode terminals in a shape housed in the body, but is a single battery element that is the smallest storage element composed of a pair of positive and negative electrodes It is a storage battery in a broad sense intended for batteries.

Or the voltage of the storage battery is detected, the storage battery is selectively charged according to the detected voltage value, the voltage value history of the storage battery is recorded, the quality of the storage battery is judged according to the history, and such storage operation The storage battery storage method is characterized in that the storage battery storage method is characterized in that it is repeatedly performed at a time interval determined by the slope of the voltage drop of the storage battery, the current storage battery voltage, and the first threshold voltage for determining the start of charging. The problem can be solved.

Or, a storage battery for selecting a specific storage battery to be charged / discharged from a plurality of storage batteries when a power source for charging / discharging the storage battery, a voltage detection unit for detecting the voltage of the storage battery, and a voltage detection value of the voltage detection unit is lower than a predetermined value a selection function unit, based on the history of the detection voltage of the voltage detecting unit have a, and determining the quality determination means the quality of the battery, such storage operation, the slope of the voltage drop of the battery, the current of the storage battery The above-mentioned problem can also be solved by a storage battery storage device that is repeatedly performed at a time interval determined by the above voltage and the first threshold voltage for determining the start of charging .

  When the present invention is applied, it is possible to prevent functional deactivation due to overdischarge of the storage battery, and it is possible to easily select a storage battery in which a malfunction such as a micro short circuit occurs during storage.

  Hereinafter, the embodiment will be described in detail for each example. In the second and third embodiments, the description of the same configuration as that of the first embodiment is omitted.

  In order to achieve the above object, the present invention is configured as follows. FIG. 1 shows a schematic configuration diagram of the storage device. In FIG. 1, those having two or more identical parts are denoted by the same reference numerals, and a part of the description is omitted. A plurality of storage batteries 2 are arranged in parallel to the power source 1, and a switch 7 that switches between charging and discharging in series with each storage battery is connected to the storage batteries 2 connected in parallel. A plurality of storage batteries 2 and a voltage detector 4 are connected to the power source 1 in parallel. Since the storage battery selection function unit 3 selects a storage battery using the switch 7, the voltage of the storage battery selected by the storage battery selection function unit 3 can be measured.

  The pass / fail judgment function unit 5 compares the voltage measurement value obtained by the voltage detection unit 4 with a preset threshold voltage alone or periodically, and determines whether or not the storage battery 2 needs to be charged and passes the test. Is required, the battery 2 is charged until it reaches a predetermined storage voltage value. At this time, if a defective storage battery is found in the pass / fail judgment function unit 5, an alarm display command is output to the warning display function unit 6. Charging the storage battery 2 is performed by switching the switch 7 with respect to the storage battery 2 selected from the storage battery selection function unit 3.

  The storage battery storage device includes a plurality of Hall CT and shunt resistance type current sensors and the like, and measures current values of each storage battery (not shown) and measures the voltage values of the storage batteries connected in parallel. The voltage detection part 4 which has. The voltage detection unit is composed of an independent PT (Potential Transducer) or an electronic component such as a voltage dividing resistor, an operational amplifier, or an A / D converter.

  The storage battery storage device has a terminal for connecting a positive electrode and a negative electrode for forming a current path from the power source 1, and this terminal has a shape that can be easily connected to the storage battery, and the terminal coupling portion has an insulating coating shape. Is desirable. Further, in order to prevent an inrush current, an appropriate value resistor may be connected to the switch 7 in consideration of the current capacity of the charge / discharge power source and the allowable current of the storage battery. For example, the power source 1 has a configuration in which a voltage detection unit 4 is connected in parallel with a plurality of storage batteries 2. In addition, the power source 1 in the storage device only needs to include at least a charger and does not necessarily have a discharge function, so that the size of the device can be reduced.

  The quality determination function unit 5 will be described with reference to FIG. The pass / fail judgment function unit 5 includes an operation unit 11 for inputting storage battery information and an operation command, an operation processing unit 13 for calculating information input by the operation unit 11, and a data recording unit 14 for recording an output of the operation processing unit 13. The display unit 12 can check the calculation result and operation status of the calculation processing unit 13.

  The display unit 12 displays the state of the storage battery and the like, and may be disposed at the connection unit of each storage battery. The arithmetic processing unit 13 selectively turns on the switch 7 by the storage battery selection function unit 3 and receives the voltage of the selected storage battery 2 from the voltage detection unit 4.

  If charging is necessary as a result of the calculation by the arithmetic processing unit 13, the storage battery selection function unit connects the storage battery and the power source, and the storage battery is charged. Since the storage battery is selected by the storage battery selection function unit 3 and can be charged / discharged only when the switch 7 is turned on, the power supply capacity of the power supply 1 can charge the capacity of one storage battery 2 within about one hour. It only needs to have capacity.

  Next, the voltage adjustment of a storage battery is demonstrated using FIG. The pass / fail judgment function section 5 sequentially changes the connection between the power source 1 and the storage battery 2 by the storage battery selection function section 3, and charging is required when the measured voltage falls below the threshold value Vth of the voltage during storage. And the selected charging means is charged to the storage set voltage Vh.

  When the above charging is repeated during the storage time of the storage battery, a storage battery with a long voltage drop period and a storage battery with a short voltage drop period appear as shown in FIG. 4A and FIG. 4B. A storage battery with a long voltage drop to the threshold voltage Vth is a good product, but a storage battery in which a voltage drop occurs at a certain slope or more is considered to have a defect such as a minute short circuit in the battery inside the storage battery or an abnormal control circuit. For this reason, in this embodiment, the number of times that the threshold value Vth has been lowered or the voltage drop speed during the storage period is stored in the data recording unit 14, and the grade is determined depending on the number of times or the voltage drop speed that has fallen below the threshold value Vth during the same period. Separation is performed to discriminate between non-defective products and defective products, and the defective products are selected together with the voltage adjustment of the storage battery. Details will be described later.

  The operation at the time of storage in the present invention will be described with reference to FIG. First, a storage battery terminal is connected to a predetermined storage battery connection terminal in the storage device. One set of connection terminals that can charge one storage battery 2 is defined as one line, and the storage device has terminals for a plurality of lines. At this time, the switch 7 of the line to be connected is opened, and the storage battery, the power source, and other circuits such as the voltage detection unit are connected in an open circuit state, that is, in an electrically disconnected state. Here, both positive and negative terminals may be connected by a single connector, or may be connected by positive and negative connectors. Further, it is desirable that the terminal is not exposed and has a shape that is not easily touched by a high voltage (step 1).

  Next, an identification number is assigned to the connection line, and the connected storage battery 2 can be selected by the switch 7 for selecting the corresponding storage battery. Next, the storage device is turned on to start the system (step 2). Here, when the battery is connected after the system is started, the power source 1 operates only on the line to which the storage battery is connected in advance from the operation unit 11 so that the power source 1 does not operate on the connected storage battery. Specify the line and input. It may be provided with a method of interlocking the storage battery connecting portion.

  Next, the storage battery 2 information such as the initial capacity of the storage battery 2, the relationship between the remaining capacity of the storage battery and the open circuit voltage, the battery capacity, the maximum current value, the lot number and serial number of the connected storage battery, the arrival date, and the manufacturing date are manipulated. Input from the unit 11 (step 3). In addition, as for these information, you may read information, such as RFID attached to a storage battery or attached to a storage battery, and a barcode directly with a dedicated interface.

  Next, the threshold voltage Vth, storage set voltage Vh, charge upper limit voltage Vhh, overdischarge voltage VL, overcharge protection voltage Vov, voltage check interval t, etc. for starting charging of the storage battery are displayed on the condition setting screen for charging and discharging the storage battery. Set from the operation unit 11. Here, the charging upper limit voltage Vhh is set to a value equal to or higher than the storage setting voltage Vh in consideration of IR drop due to the charging current. Further, by inputting protection set values such as overcharge warning voltage Vov, charging current Ic, overcurrent Iov, and maximum charging time tch, charging can be performed more safely (step 4).

  Next, a storage start command is input and voltage adjustment is performed (step 5). Next, a history of voltage adjustment results is recorded in the data recording unit 14, and the quality determination function unit 5 determines the quality of the storage battery (step 6). Next, each information of the storage battery determined to be defective is output to the warning display function unit 6 (step 7). Next, the setting for the next activation is performed (step 8). For the second and subsequent storage operations, step 2 to step 8 are repeated. However, Step 5 may be performed by omitting Step 3 and Step 4 from the second system activation. The storage operation is terminated at the end of the storage period of the storage battery. Steps 5 to 8 will be described in detail below.

FIG. 6 shows the voltage adjustment operation in step 5 of FIG. 5 in more detail. First, a save start command is input (S501). Next, the switch 7 is switched by the storage battery selection function unit 3, the storage batteries 2 are selected in order, and the voltages for all the storage batteries 2 are measured (S502). If there are a plurality of switches 7 for voltage measurement and charging, the switch 7 may be switched only for voltage measurement.
At this time, all the voltage information of the storage battery is recorded in the data recording unit together with the time as a report.

  Next, the acquired voltage V of the storage battery is compared with the threshold voltage Vth at the start of charging (S503). When V> Vth, it is determined that charging is unnecessary. When V <Vth, it is compared with the overdischarge voltage VL, and when V <VL, it is determined as a defective storage battery, and a warning signal is output to the warning display function unit 6 without charging. On the other hand, when Vth ≧ V> VL, the charging time and the charging capacity are calculated based on the condition data input in advance in step 4 of FIG. 5 (S504).

  Next, the storage battery to be charged is selected, and the charging switch 7 is connected to start charging (S505). It is desirable that the charging is a constant current / constant voltage charging or a constant current charging with a low rate current so as to suppress the influence of the voltage drop due to the internal resistance of the storage battery at the time of open circuit immediately after the end of charging. After completion of charging, the voltage V of the storage battery in the open circuit state is compared with the storage set voltage Vh (S506). If V ≧ Vh is not satisfied, charging is performed again in steps S503 to S506, and the storage battery satisfying V ≧ Vh ends charging. Here, a plurality of current detectors (not shown) for measuring each current value flowing through each storage battery 2 during switching of the circuit by the switch 7 or charging are composed of Hall CT, a shunt resistance type current sensor, etc. When an overcurrent is detected by the current detection unit, the circuit is opened without being charged immediately.

  Next, it is examined whether there is a storage battery having a voltage lower than the threshold voltage Vth among other storage batteries (S507). If there is another storage battery having a voltage lower than the threshold voltage Vth, the switch 7 is switched to connect the power source to the target storage battery (S508). Next, the charging time and charging capacity corresponding to the target storage battery are calculated, and other settings are read (S509). Next, returning to S505, the storage battery is selected and charging is started. The above-described steps are repeated until there are no storage batteries having a voltage lower than the threshold value. When the voltages V of all the storage batteries to be charged become higher than the storage set voltage Vh, the process proceeds to step 6.

  In step 6, the voltage measurement value of each storage battery measured in step 5 is recorded in the data recording unit 14 at least before charging and after charging (including the time of storage start). The measured value is recorded together with time information, and the number of times of charging is recorded for each storage battery.

  Further, if the measured voltage V of the storage battery is smaller than the discharge lower limit voltage VL during voltage measurement in step 5, the storage battery is determined to be defective and charging is not performed. Furthermore, using the information of the storage battery 2 after the voltage adjustment charging, the voltage before the voltage adjustment charging, and the storage period recorded in the data recording unit, the opening measured from the charging upper limit voltage setting value before the start of charging is used. The voltage difference slope α ′ per unit time is calculated by dividing the circuit voltage difference by the storage time. If the slope α ′ of the voltage drop is larger than the slope α of the voltage drop in the case of a normal storage battery, it is determined as a defective storage battery if it is a large value that deviates from the allowable value. In addition, a storage battery in which the number of times of charging is clearly more than the allowable value than the average number of times of charging of a normal storage battery in the same manufacturing period and specification in the same storage period is determined as a defective product.

  In step 7, the storage battery determined to be defective in step 6 is displayed as a warning on the warning display function unit 6. The warning at this time is implemented by a sound of a display, a pilot lamp, a buzzer, or the like.

Next, in step 8, the next start-up setting is performed using the information of the storage battery 2 after voltage adjustment charging, the voltage before voltage adjustment charging, and the storage period recorded in the data recording unit. The first time at the start of storage is considered to be the case where charging is not performed in step 5 in most cases.
In this case, the slope α of the voltage drop per unit time when a normal storage battery is stored in advance is input in Step 3 or Step 4, and the slope α is obtained by subtracting the threshold voltage Vth from the storage battery voltage V at the start of storage. And the time until the threshold voltage Vth is reached is estimated. The start time is set to be after the estimated time. Preferably, after the elapse of time until the SOC of the threshold value decreases by 1 to 2%. From the second time onward, use the information of the storage battery 2 after voltage adjustment charging, the voltage before voltage adjustment charging, and the storage period recorded in the data recording unit, and measure before charging starts from the upper limit voltage setting value. The voltage difference slope α ′ is calculated by dividing the difference in the open circuit voltage by the storage time. Further, the current voltage difference between the storage battery voltage V and the threshold voltage Vth is divided by the slope α ′, and the next time when charging is required is calculated. The above calculation is performed for all the storage batteries, and the battery that has the earliest date and time required to be charged next is set as the next activation start date and time. The next start-up setting may be performed for all storage batteries, or the storage batteries may be grouped and set for each group.

  The next startup start date and time obtained is stored in the storage device with an internal or external timer, etc., and when the next startup start date and time elapses, the storage device power supply and voltage detector are automatically started. . Such automatic activation of the storage device is executed until the target storage battery is removed due to shipment or failure. In the case of removal due to shipment or failure, information on the end of storage is input to the pass / fail judgment function unit 5 by an input from the operation unit 11, and it is excluded from automatic charge / discharge until there is a new storage battery connection.

  As described above, charging / discharging during storage of the storage battery is performed. By appropriately taking the width of the storage setting voltage Vh and the threshold voltage Vth for starting charging, the charging time of each storage battery can be adjusted. Therefore, for example, even when the threshold voltage Vth is set to the voltage at SOC 0% and the storage setting voltage Vh is set to the fully charged SOC 100% voltage, the charging time at the 1C current value can be charged in about one hour. In actual operation, both Vth and Vh are within this range, so that the voltage can be adjusted in a shorter time. When the charging time is set to be completed in one hour, it is possible to complete charging of 24 storage batteries 2 in one day with one power source.

  When assembling a battery system from multiple storage batteries, the distribution of the storage battery capacity is reduced in a system with a high voltage in series connection, and in a system with a large capacity in a parallel connection, heat is generated due to a large current cross current between the storage battery connections. Therefore, it is necessary to connect the storage battery voltages so that the voltages of the storage batteries are aligned within a specified range.

  Therefore, the storage device of the present invention records the history of the number of times of charging so far, the history of the slope of the voltage drop, etc. in the data recording unit, and selects the storage battery with the same level of storage battery quality in the arithmetic processing unit 13, A function of displaying on the display unit 12 is provided. With this quality level selection function, it is possible to reduce the quality variation of the storage battery, and the reliability of the battery system is improved by configuring the battery system with a group of storage batteries whose quality is selected to be the same level. Further, in order to homogenize the voltages of the plurality of storage batteries 2 that have been selected to have the same quality with higher accuracy, the voltage of the storage batteries is finely adjusted by performing a small amount of discharge or charging at the time of shipment. Thereafter, the history after fine voltage adjustment is left in the data recording unit, and the selected storage battery is disconnected from the storage device. A battery system is composed of a plurality of separated storage batteries.

  FIG. 7 shows an example of voltage fine adjustment when shipping the storage battery. First, the shipping mode is activated (step N1). Existing data recorded in the data recording unit 14 during storage of the storage battery is read (step N2), and selection conditions such as the required number of storage batteries and voltage variation tolerance are set (step N3). An appropriate storage battery 2 that satisfies the conditions set with reference to the data recorded in the data recording unit 14 is selected. The selected storage battery 2 is displayed on the display unit 12. Here, the reference voltage Vb at the time of shipping assembly is set. Vb may be manually input from the operation unit 11 or may be called in advance when stored in advance (step N4).

  Next, the selected storage battery 2 is sequentially switched by the storage battery selection function unit 3 and the switch 7, and the voltage is measured by the voltage detection unit 4 (step N5). Charging or discharging is set (step N6). Each selected storage battery 2 is charged / discharged, and the voltage V of the storage battery 2 is made equal to the reference voltage Vb (step N7). Whether the voltage V of the storage battery 2 is equal to the reference voltage Vb is compared. Here, when the tolerance of the voltage variation is within several percent of the arbitrarily set storage battery capacity, it is assumed that the voltage V of the storage battery 2 is equal to the reference voltage Vb (step N8).

  Those that do not satisfy the condition of Step N8 repeat Steps N4 to N8, and when the condition of Step N8 is satisfied, only the selected storage batteries 2 are connected to each other (Step N9). When the selected storage batteries 2 are connected in parallel, the power supply 1 is electrically disconnected. When the selected storage batteries are connected in parallel, the voltages match due to cross current. The current value and voltage value at this time are recorded for a predetermined period, and are displayed as the final storage battery voltage when the slope of the change in current and voltage becomes a value close to zero, for example, 1 mV / sec.

  Further, a display is made so that it can be seen that each storage battery connected in step N9 is selectively connected. For example, an identification number or the like of the storage battery connected to the display unit 12 may be displayed, or a system that can be identified by color by lighting a light emitting element or a lamp installed in the storage battery may be used. The connected storage batteries are sequentially opened from the storage device, a storage end command is input, the history is stored in the data recording unit 14, storage of the storage batteries is ended, and the storage batteries are shipped. At this time, about what has a function which can record a voltage log | history in a storage battery, writing may be implemented and you may prepare for a storage battery.

  When the internal resistance of the storage battery is uneven or when the storage battery becomes unusable due to a minute short circuit or a circuit failure, the storage battery is replaced. When the present invention is applied, it is possible to prevent overdischarge due to self-discharge of the storage battery, and it is possible to easily select a short-circuit or a high internal resistance during the storage period. By sorting by quality, it becomes possible to improve the reliability of a large-scale battery system.

  In addition, it has become possible to shorten the time and procedure conventionally required to individually charge and discharge each storage battery before incorporating it into the battery system, and to reduce the device scale of the power supply. Furthermore, in the manufacturing process of the battery system, the process of aligning the voltages to connect the storage batteries is automatically performed, so the connection process of the battery system can be shortened. Since the storage battery history is also managed, maintenance is facilitated.

  In this embodiment, charging is performed with constant current / constant voltage charging or constant current charging with a low rate current so as to suppress the influence of voltage drop due to the internal resistance of the storage battery in the open circuit immediately after the end of charging. In order to recover the voltage near the reference storage voltage, the battery may be charged with a constant current up to a voltage equal to or higher than the storage reference voltage, or may be charged with a constant current and constant voltage higher than the rated current up to the storage reference voltage.

  Next, an example applied to a lithium ion battery is shown. A storage battery with a rated voltage of 3.6 XV and a rated capacity B Ah in which X batteries with an average voltage of 3.6 V with an upper limit of 4.1 V and a lower limit of 2.7 V and an average voltage of 3.6 V are stored. The storage battery has a built-in control circuit capable of communicating each voltage of the single cell in the storage battery to the host control circuit, and has a signal output terminal separately from the power connection terminal.

  In addition to the charging / discharging connection terminals, the storage device also includes a terminal that receives an output of a terminal that communicates each cell voltage to the upper level. When the voltage is determined in step 6 of the first embodiment, the cell voltage is also acquired at the same time, whereby it is possible to calculate the slope of each voltage and voltage drop for each cell. In a high-voltage storage battery having a large series number X in the housing, even if a defective battery is mixed among a plurality of single batteries, the influence of the voltage may appear to be small, and a defect may not be found. Since the voltage can be acquired, it is possible to detect that the single cells having significantly different characteristics are mixed in the series connection before the system is incorporated, and to take out it as a defect, thereby preventing the malfunction of the system. When a storage battery failure occurs, there is an advantage that it is easy to estimate the cause of the malfunction of the control circuit and the unit cell itself depending on which unit cell in the housing is defective.

  Further, when there is a data storage area in a control circuit or the like built in the storage battery by communication, the history is stored and used during maintenance.

  Since lithium ion batteries have a high energy density, when connecting multiple storage batteries in series and parallel, for safety reasons, the SOC is low so that the discharge energy is reduced even if a short circuit occurs, preferably in the range of SOC 50% to SOC 0% It is desirable to store in. For example, the threshold voltage at the start of charging is the voltage at SOC 20%, and the storage voltage is the voltage at SOC 50%. When the selected storage battery 2 is incorporated into the system, the required voltage and voltage difference are determined after determining the plurality of storage batteries 2 required in step N6 of FIG. 7 in the shipping mode so that a desired voltage can be obtained at the time of removal. If larger, each storage battery is sequentially selected and discharged or charged to adjust the voltage, and then the voltages are equalized by step N7 in FIG. 7 in which all the selected batteries are connected in parallel.

  In addition, since the storage setting voltage Vh has different characteristics depending on the types of constituent materials such as the positive electrode active material, the negative electrode active material, and the electrolyte solution of the lithium ion battery, a voltage that reduces the deterioration effect during storage is selected according to the battery specifications The storage battery can be used more effectively.

  An example of the voltage adjustment at the time of storage in case a storage battery is a nickel metal hydride battery is shown. At the end of charging when fully charged, the measured voltage rises once and then drops. For this reason, a configuration capable of performing ΔV control for detecting the slope of the voltage change and terminating charging is desirable. In order to control the end of charging of the charging / discharging unit 1 in the storage device, a voltage change at the time of charging may be recorded, and a full charge may detect ΔV that decreases once the voltage increases. With a configuration in which a heat detection element such as a thermocouple or a thermistor is added, these pieces of information can also be used for quality determination.

  Here, FIG. 8 shows a schematic configuration diagram of another storage device different from the schematic configuration diagram of the storage device shown in FIG. The same parts as those shown in FIG. 1 are denoted by the same reference numerals, and a part of the description is omitted. The configuration of the storage device shown in FIG. 8 can be applied to the above-described embodiments. A plurality of storage batteries 2 are arranged in parallel to the power source 1, and a switch 7 that switches between charging and discharging in series with each storage battery is connected to the storage batteries 2 connected in parallel. A plurality of storage batteries 2 and a voltage detector 4 are connected to the power source 1 in parallel. A voltage measurement selection switch 7 ′ is connected in series with the voltage detection unit 4. Since the storage battery selection function unit 3 selects a storage battery using the voltage measurement selection switch 7 ′, the voltage of the storage battery selected by the storage battery selection function unit 3 can be measured. The pass / fail judgment function unit 5 compares the voltage measurement value obtained by the voltage detection unit 4 with a preset threshold voltage alone or periodically, and determines whether or not the storage battery 2 needs to be charged and passes the test. Is required, the power supply output release switch 8 is closed and charging is performed until the storage battery 2 reaches a predetermined storage voltage value. At this time, if a defective storage battery is found in the pass / fail judgment function unit 5, an alarm display command is output to the warning display function unit 6. Charging the storage battery 2 is performed by switching the switch 7 with respect to the storage battery 2 selected from the storage battery selection function unit 3.

  In each of the above-described embodiments, a plurality of unit cells are connected in series to form an assembled battery, or a configuration in which a plurality of units are connected, and in appearance, in a single block shape or a shape accommodated in a housing. Although a module having a current input / output path with a pair of positive electrode terminal and negative electrode terminal is defined as a storage battery, each embodiment can be applied even if the storage battery is replaced with a single battery.

  The storage battery according to the present invention is not limited to a lithium secondary battery, and can be applied to all battery systems in which chargeable / dischargeable storage elements such as nickel metal hydride batteries, NAS batteries, lead batteries, and electric double layer capacitors are connected in multiple parallel and multiple series. is there. In particular, the secondary battery system and the electric double layer capacitor in which inversion due to overdischarge and functional deactivation due to irreversible reaction are problematic when completely discharged to OV have a remarkable effect of introducing the present invention. Effective for the stable maintenance of large-scale battery systems such as hybrid vehicles, electric vehicles, electric motorcycles, electric buses and trucks, railway vehicles, construction machinery, ground power supply facilities, substations, etc. that can use these battery systems .

  If the internal resistance of the storage battery in a large-scale system is uneven, especially if the battery becomes unusable due to a short circuit, etc., the storage battery must be replaced and the system life is shortened from the expected value. Happens. When the present invention is applied, it is possible to prevent functional deactivation due to overdischarge resulting from self-discharge of an expensive storage battery, and to easily select a storage battery in which a defect such as a micro short circuit occurs during storage. Therefore, it is possible to improve the reliability of a large-scale storage battery system by selecting and using the storage battery performance by grade.

  In addition, it has been possible to shorten the time and procedure required to charge and discharge each storage battery before installation, and to reduce the scale of the charge / discharge power supply for adjusting the voltage of the storage battery. It becomes.

  Furthermore, since the complexity in the process is eliminated and the process of aligning the voltages for connecting the storage battery is automatically performed, the connection process of the assembled battery system can be shortened. Since the history of the storage battery is also managed, there is an advantage that maintenance is easy.

1 is a schematic configuration diagram of the present invention. It is a schematic diagram of the voltage change of the storage battery in this invention. It is the figure which showed the detail of the quality determination function of this invention. It is a schematic diagram about the voltage change of the storage battery when this invention is applied. It is the figure which showed the operation | movement flow of this invention. It is the figure which showed the detail of step 5 of the operation | movement flow in this invention. It is a flowchart at the time of the battery shipment which is embodiment of this invention. It is another structure schematic diagram of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power supply 2 Storage battery 3 Storage battery selection function part 4 Voltage detection part 5 Pass / fail judgment function part 6 Warning display function part 7 Switch 7 'Voltage measurement selection switch 8 Power supply output release switch 11 Operation part 12 Display part 13 Arithmetic processing part 14 Data recording part

Claims (16)

A storage battery storage device that can be connected to a plurality of chargeable / dischargeable storage batteries and stores the plurality of storage batteries,
A power source for charging and discharging the storage battery;
A voltage detector for detecting the voltage of the storage battery;
A data recording unit for recording the detected voltage of the voltage measuring means;
Have a, a quality determining function unit determines the quality of the quality of the battery from the voltage information recorded in the data recording unit,
In a state in which the battery is not energized from the power source, a predetermined time until the start of the next auxiliary charging is determined by the slope of the voltage drop of the storage battery, the current storage battery voltage, and the first threshold voltage of the reference for performing the auxiliary charging of the storage battery. Find the time interval,
Voltage detection of the storage battery by the voltage detection unit, charging / discharging of the storage battery up to a predetermined voltage that is a second threshold voltage by the power source, which is performed when the detection voltage falls below the first threshold voltage, and A storage battery storage device that repeatedly performs a storage operation for performing pass / fail judgment of the storage battery based on a data recording unit at the predetermined time interval . The storage battery storage device of claim 1,
The quality determination of the storage battery is as follows:
Means for determining a defective product when the detection voltage of the storage battery is lower than a third threshold voltage which is a discharge lower limit voltage;
And means for determining that the detected voltage of the storage battery recorded by the data recording unit is a defective product when the number of times the unit battery detection voltage is lower than the first threshold voltage is greater than a permissible value,
A storage battery storage device comprising: means for determining pass / fail based on a slope of a voltage drop per unit time based on the detected voltage of the storage battery recorded by the data recording unit. The storage battery storage device of claim 1,
The quality determination function unit determines that the storage battery is defective when the rate of decrease in the detection voltage of the storage battery is faster than a predetermined value. The storage battery storage device of claim 1,
The storage battery storage device includes means for charging the storage battery with the power supply when a detection voltage of the storage battery is lower than the first threshold voltage ,
The storage battery storage device, wherein the pass / fail determination function unit determines pass / fail of the storage battery according to the number of times the storage battery is charged per unit time . The storage battery storage device of claim 1,
The storage battery storage device, when the quality determination function unit determines that the storage battery is a defective product,
A storage battery storage device comprising a warning display function unit for displaying a warning of the storage battery. The storage battery storage device of claim 1,
One or more arbitrary storage batteries are selected from the plurality of storage batteries, and a storage battery selection function unit that electrically connects the selected storage batteries to the power source is provided.
The storage battery storage device has means for selecting and electrically connecting any number of the storage batteries having substantially equal detection voltage drop rates. The storage battery storage device of claim 6,
The storage battery storage device has means for electrically connecting the storage batteries having approximately the same number of times of charging. A storage battery storage method for storing a plurality of storage batteries,
Detecting the voltage of the storage battery,
Charging the storage battery according to the detected voltage value,
Record the voltage value history of the storage battery,
The quality of the storage battery is determined according to the history ,
The predetermined time interval is determined by the slope of the voltage drop of the storage battery, the current storage battery voltage, and the first threshold voltage for determining the start of charging of the storage battery,
A storage operation for detecting the voltage of the storage battery, charging the storage battery according to the detected voltage value, recording a history of the voltage value of the storage battery, and determining whether the storage battery is good or bad according to the history is the predetermined time. A storage battery storage method, which is repeatedly performed at intervals . The storage battery storage method according to claim 8,
A storage battery storage method comprising electrically connecting a plurality of storage batteries having substantially the same voltage drop speed and voltage calculated from the history. A storage battery storage device connected to a plurality of storage batteries and storing the plurality of storage batteries,
A power source for charging and discharging the storage battery;
A voltage detector for detecting the voltage of the storage battery;
A storage battery selection function unit that selects a specific storage battery to be charged / discharged from the plurality of storage batteries when a voltage detection value of the voltage detection unit is lower than a predetermined value;
Quality judgment means for judging the quality of the storage battery based on the history of the detection voltage of the voltage detection unit,
A predetermined time interval is determined by the slope of the voltage drop of the storage battery, the current storage battery voltage, and the voltage of the predetermined value for determining whether the storage battery can be charged,
Storage operation for performing voltage detection of the storage battery by the voltage detection unit, charging / discharging of the storage battery performed when the detection voltage is lower than the predetermined value, and quality determination of the storage battery based on a history of detection voltage A storage battery storage device, which is repeatedly performed at predetermined time intervals . The storage battery storage device of claim 10,
The storage battery storage device, wherein the quality determination unit determines that the storage battery is defective when a voltage drop rate calculated from a history of detection voltages of the voltage detection unit is faster than a predetermined value. The storage battery storage device of claim 8,
The storage battery storage device includes a warning display function unit that displays a warning when the quality determination unit determines that the storage battery is defective. The storage battery storage device of claim 11,
The storage battery storage device has means for electrically connecting the storage batteries having substantially the same voltage drop rate and the detected voltage. The storage battery storage device according to any one of claims 1 to 7, wherein the storage battery storage device records an internal unit cell voltage constituting the storage battery by communication, calculates a voltage drop of the unit cell voltage, A storage battery storage device comprising a single cell pass / fail judgment unit for judging pass / fail. A unit for storing a plurality of unit cells in series to form an assembled battery, or an assembled battery configured by connecting a plurality of such units, wherein the claim is any one of claims 1 to 7, or The storage battery storage device according to any one of claims 10 to 14. The storage battery storage method according to claim 8 or 9,
The storage battery is a storage battery storage method characterized in that a plurality of unit cells are connected in series to form an assembled battery, or a plurality of such units are connected.

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