JP6566314B2 - Secondary battery current control device - Google Patents

Description

  The present invention relates to a secondary battery current control device for controlling discharge or charging current of a secondary battery.

  2. Description of the Related Art A power supply apparatus that temporarily stores power in a secondary battery and supplies the power stored in the secondary battery to a load as needed is widely used. As the secondary battery, for example, a lead battery, a nickel metal hydride battery, a lithium ion battery, and other various batteries are used. The power source that supplies power to the secondary battery is not particularly limited, and various power sources exist.

  Conventionally, in a power supply device for supplying power stored in a secondary battery to a load, technical development for increasing the storage capacity of the secondary battery and extending the life of the charge / discharge cycle of the secondary battery Technology development. As a result, the storage capacity of the secondary battery is improved, and a significant improvement is also seen with respect to deterioration in the charge / discharge cycle of the secondary battery. As a technique for suppressing deterioration in the charge / discharge cycle of the secondary battery and improving the life, for example, making the discharge current of the secondary battery pulsed has been proposed. By making the discharge current into a pulse shape, deterioration of the active material of the secondary battery is suppressed, and the life of the charge / discharge cycle can be extended. Such a technique is disclosed in Patent Document 1, for example.

JP 2006-325331 A

  Improving the life of the secondary battery charge / discharge cycle is a great achievement and has a great social contribution. However, the market needs are not limited to the demand for extending the life of the secondary battery, and various new needs are generated as the market expands. As a major need, there is a need to further increase the power supply available time to the load for each charge of the secondary battery. For example, taking an electric vehicle as an example, there is a strong need to further increase the distance that can be traveled by one charge. In addition, for example, in an illumination device that uses sunlight, there is a need to make the illumination time possible with daytime charging power as long as possible. In order to meet such needs, conventionally, development has been focused on improving the storage capacity of the secondary battery itself.

  It is very important to improve the storage capacity of the secondary battery itself. However, not only that, but also improvement in efficiency in power supply from the secondary battery to the load, that is, reduction of loss is an important issue to be improved. If the efficiency in power supply operation from the secondary battery to the load can be improved, that is, the loss can be reduced, the power supply time to the load can be made longer for the same charge amount of the secondary battery, and the above needs are answered. be able to.

  An object of the present invention is to provide a secondary battery current control device that can improve the efficiency of power supply from the secondary battery.

1st invention for solving the said subject is a current control apparatus of the secondary battery which controls the electric current of the secondary battery which supplies electric power to load, Comprising: The said current control apparatus is based on the stored electric power. A power storage device that supplies current; a connection device that connects the power storage device to the secondary battery in parallel; and a control device that controls a connection state of the connection device, the control device including the secondary battery. Is connected to the load, the connection device is operated at a predetermined cycle, the power storage device is repeated at a predetermined cycle, and connected in parallel to the secondary battery , and the secondary battery is connected in series. And at least a first secondary battery and a second secondary battery, and the power storage device included in the current control device includes at least a first capacitor and a second capacitor. The first condenser The secondary battery is repeatedly connected in parallel with the first secondary battery in a predetermined cycle, and the second capacitor is repeatedly connected in parallel with the second secondary battery in a predetermined cycle. It is a current control device.

A second invention for solving the above problem is a current control device for a secondary battery that controls a current of a secondary battery that supplies power to a load, and the current control device is based on the stored power. A power storage device that supplies current; a connection device that connects the power storage device to the secondary battery in parallel; and a control device that controls a connection state of the connection device, the control device including the secondary battery. Is connected to the load, the connection device is operated at a predetermined cycle, the power storage device is repeated at a predetermined cycle, connected in parallel to the secondary battery, and the power storage device is connected to the secondary battery. A current control device for a secondary battery, wherein current is temporarily supplied from the power storage device to the secondary battery when connected in parallel.

According to a third aspect of the present invention for solving the above-mentioned problems, in the secondary battery current control device according to the first aspect, the first capacitor or the second capacitor is the first secondary battery or the second secondary battery. The current control of the secondary battery, wherein the terminal voltage of the first capacitor or the second capacitor is larger than the terminal voltage of the first secondary battery or the second secondary battery when connected to Device.

A fourth invention for solving the above-mentioned problems is a current control device for a secondary battery according to one of the first to third inventions , wherein the control device is configured such that the secondary battery is the load. In addition to the state where the secondary battery is supplied with electric power from the outside and stores the electric power, the connecting device is operated at a predetermined cycle, and the power storage device is operated at a predetermined cycle. The secondary battery current control device is repeatedly connected in parallel to the secondary battery.

A fifth invention for solving the above-described problems is a current control device for a secondary battery according to one of the first to fourth inventions , wherein the control device has a cycle longer than 0.1 seconds. The current control device for the secondary battery is characterized in that the connection device is operated repeatedly.

A sixth invention for solving the above-described problems is a secondary battery current control device according to one of the first to fifth inventions , wherein the power storage device has a capacity of 10 Farads or more. It is the electric current control apparatus of a secondary battery characterized by the above-mentioned.

A seventh invention for solving the above-mentioned problem is a secondary battery current control device according to the sixth invention , wherein the power storage device has a capacity of 100 Farad or more. Current control device.

  ADVANTAGE OF THE INVENTION According to this invention, the electric current control apparatus of a secondary battery which can improve the efficiency of the electric power supply from a secondary battery can be obtained.

It is a circuit diagram which shows the electric power supply apparatus structure to the load to which this invention is applied. It is explanatory drawing explaining an example of the electric power load pattern to load. It is a current waveform flowing through the first secondary battery 80. It is a current waveform flowing through the power storage device 120. It is a current waveform flowing through the second secondary battery 90. It is a current waveform flowing through the power storage device 130. It is a graph based on a simulation result. FIG. 6 is an explanatory diagram for explaining a power storage operation for storing electric power in a secondary battery.

1. 1. Description of Embodiments 1.1 Description of Basic Configuration of Embodiments A mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing a configuration of a power supply device to a load to which the present invention is applied. A load 50 is electrically connected to a secondary battery 70 that stores DC power via a terminal 62 and a terminal 64. In an actual product, an open / close means such as a power switch and a safety device such as a fuse are provided between the secondary battery 70 and the load 50. The configuration and operation of the present invention will be described with reference to FIG. They are for the purpose and are omitted to avoid complications.

In this embodiment, a secondary battery current control device 100 is further provided to control the discharging or charging current of the secondary battery 70. As will be described below, in the state where power is supplied from the secondary battery 70 to the load 50 by providing the secondary battery current control device 100, the current I _b1 and the current I _b2 flowing through the secondary battery 70 are periodically changed. As a result, the internal loss of the secondary battery 70 can be reduced, and as a result, the amount of power supplied to the load 50 based on predetermined stored power can be increased. In other words, the power supply time to the load 50 based on the predetermined stored power can be increased.
1.2 Description of Load 50 The load 50 is not particularly limited. The load 50 may be, for example, a lighting device or a vehicle driving motor. In applying the present invention, the load 50 is not particularly limited, and the present invention can be applied to various types of loads.

For example, the load 50 may be a load that consumes DC power, or may be a load that operates by receiving AC power. Further, even when the load 50 is a load that consumes DC power, the load may be a load that can be supplied with the DC voltage supplied from the secondary battery 70 as it is, or supplied after being converted to an appropriate voltage. It may be a load. In this case, it means that the load described as the load 50 includes a voltage conversion device. In the case of a load that consumes AC power, it means that the load described as the load 50 includes a power conversion device that receives DC power and generates AC power.
1.3 Description of Secondary Battery 70 In this embodiment, the secondary battery 70 has a first secondary battery 80 and a second secondary battery 90 connected in series. Each of the first secondary battery 80 and the second secondary battery 90 includes at least one lithium ion secondary battery. However, this is an example, and both the first secondary battery 80 and the second secondary battery 90 constituting the secondary battery 70 are not always necessary, and only one of them may be used. Further, not only the first secondary battery 80 and the second secondary battery 90 but also a larger number of secondary batteries connected in series may be provided, for example, a third secondary battery or a fourth secondary battery.

  Furthermore, the first secondary battery 80 or the second secondary battery 90 has not only one or more series-connected lithium ion secondary batteries, but also includes lithium ion secondary batteries connected in parallel. May be. In addition, since it is thought that the capacity | capacitance of the lithium ion secondary battery connected in parallel is increased, in this case, it is a secondary battery having a larger capacity attached to the first secondary battery 80, the second secondary battery 90, etc. It can be handled as being.

The voltage supplied to the load 50 can be increased by increasing the number of lithium ion batteries connected in series to each of the first secondary battery 80 and the second secondary battery 90. In addition to the first secondary battery 80 and the second secondary battery 90 as described above, the voltage supplied to the load 50 can be increased by providing more secondary batteries connected in series. In the present embodiment, in order to make the explanation easy to understand, an example having two sets of secondary batteries of a first secondary battery 80 and a second secondary battery 90 will be described. In this embodiment, each set of the first secondary battery 80 and the second secondary battery 90 includes one or more lithium ion batteries, but the lithium ion battery is an example, and a lead secondary battery. Or other types of secondary batteries.
1.4 Description of Secondary Battery Current Control Device 100 In this embodiment, the loss of power in the secondary battery 70 can be reduced by periodically changing the current value supplied from the secondary battery 70 to the load 50. As a result, the efficiency of power supply from the secondary battery 70 to the load 50 can be improved. In order to periodically change the current value supplied from the secondary battery 70 to the load 50, a secondary battery current control device 100 is provided in this embodiment.

The secondary battery current control device 100 includes a power storage device 120 and a power storage device 130, and a connection device 140 for connecting the power storage device 120 and the power storage device 130 to the first secondary battery 80 or the second secondary battery 90 in parallel. And a control device 150 for controlling the connection device 140. In a state in which the load 50 is connected to the secondary battery 70, the control device 150 switches the connection device 140 at a predetermined cycle, for example, a one-second cycle. In this embodiment, when the terminal 142 of the connection device 140 connected to the first secondary battery 80 and the second secondary battery 90 is connected to the terminal 144, the power storage device 120 and the first secondary battery 80 are connected. Connected in parallel. In this state, power storage device 130 is not connected to second secondary battery 90 or load 50, and current I _c2 of power storage device 130 does not flow. In this state, a current that is a vector sum of current I _b1 flowing through first secondary battery 80 and current I _c1 flowing through power storage device 120 flows through load 50. In this embodiment, the current I _b2 flowing through the second secondary battery 90 is equal to the current flowing through the load 50.

Next, when the terminal 142 of the connection device 140 is connected to the terminal 146, the power storage device 120 is not connected, and the current I _c1 flowing through the power storage device 120 does not flow. On the other hand, power storage device 130 is connected in parallel to second secondary battery 90. In this state, the current flowing through the load 50 is a vector sum of the current I _c2 flowing through the power storage device 130 and the current I _b2 flowing through the second secondary battery 90. In this embodiment, the current I _b1 flowing through the first secondary battery 80 is equal to the current flowing through the load 50.

When the connection between the terminal 142 and the terminal 144 or the terminal 146 of the connection device 140 is switched at a predetermined cycle by the control by the control device 150, the power storage device 120 and the first secondary battery 80 or the power storage device 130 and the second secondary battery 90 are switched. And are connected alternately. As a result of this switching, the current I _b1 flowing through the first secondary battery 80 and the current I _b2 flowing through the second secondary battery 90 change at the predetermined intervals. Thus, by periodically changing the current flowing through the secondary battery 70, the loss of the first secondary battery 80 and the second secondary battery 90 constituting the secondary battery 70 is reduced. Loss in current supply to the load 50 is reduced, in other words, efficiency in power supply from the secondary battery 70 to the load 50 is improved. This will be described next.
2. 2. Description of Simulation Conditions and Simulation Results for Embodiment 2.1 Description of Simulation Conditions In the embodiment of FIG. 1, capacitors are used for the power storage device 120 and the power storage device 130, and the capacities of the capacitors range from 1F to 1000F. Assuming that the simulation was changed. The switching cycle of the connection device 140 is set to 1 second, and the power storage device 120 and the power storage device 130 are alternately connected in parallel to the first secondary battery 80 and the second secondary battery 90 in a cycle of 1 second. did. In this simulation, as an example, the connection device 140 sets the switching cycle to be constant under the above conditions and is 1 second regardless of the change in the power consumption of the load 50 described below.

The first secondary battery 80 and the second secondary battery 90 are constituted by lithium ion secondary batteries, and the terminal voltage V _{b1 of} the first secondary battery 80 and the terminal voltage V _b2 of the second secondary battery 90 are respectively 4V. It was changed in the range of 24V. Further, the power consumption of the load 50 as a discharge condition from the terminals 62 and 64 is set to a power load pattern in units of 100 seconds shown in FIG. 2, and this power load pattern is repeated 8 times, from time 0 seconds to time 800 seconds. A simulation was performed. In FIG. 2, only a power load pattern for 100 seconds from time 700 seconds to time 800 seconds is shown as a representative example, but the power load pattern is the same in other periods.

  FIGS. 3 to 6 are current waveforms of the simulation circuit shown in FIG. 1. Of the current waveforms based on the simulation from time 0 seconds to time 800 seconds, only 100 seconds from time 700 seconds to time 800 seconds are shown. Show. However, the current waveform at other times is almost similar to the waveform for 100 seconds from time 700 seconds to time 800 seconds, and it can be considered that the same operation is performed.

3 shows a waveform of current I _b1 flowing through first secondary battery 80, and FIG. 4 shows a waveform of current I _c1 flowing through power storage device 120. 5 shows a waveform of the current I _b2 flowing through the second secondary battery 90, and FIG. 6 shows a waveform of the current I _c2 flowing through the power storage device 130. Each of the current waveforms described in FIGS. 3 to 6 and the operations of the first secondary battery 80, the second secondary battery 90, the power storage device 120, and the power storage device 130 will be described again below.

2.2 Description of Simulation Results The results of simulation up to 800 seconds according to the above conditions will be described using the graph of FIG. As described above, the voltage V _{b1 of} the first secondary battery 80 and the voltage V _b2 of the second secondary battery 90 were changed in the range from 4V to 24V. Changes in the voltage V _b1 and the voltage V _b2 are taken as the X axis. Further, the electrostatic capacities of the power storage device 120 and the power storage device 130 were changed in the range of 1F to 1000F. This change in capacitance is taken as the Y axis.

The charging power amount at the time of starting the simulation on the power source side from the terminal 62 or 64 with respect to the load 50, in other words, the battery capacity was set to a constant value, and the battery capacity after 800 seconds of simulation was obtained. The battery capacity after simulation in the state where the secondary battery current control device 100 is not provided is defined as Q _no , the secondary battery current control device 100 is provided as the simulated battery capacity Q _pro to which the present invention is applied, and the battery The capacity ratio A of the battery capacity Q _pro to the capacity Q _no was determined. That is, the capacity ratio A is expressed by the following formula 1.

Capacity ratio A = Q _pro / Q _no (1)
The capacity ratio A expressed by Equation 1 is shown on the Z axis in FIG. In the simulation result, if the battery capacity Q _pro after the simulation is the same as the battery capacity Q _no after the simulation, the capacity ratio A is 1. If the capacity ratio A is greater than 1, the discharge time from the secondary battery 70 to the load 50 is extended by providing the secondary battery current control device 100. That is, by providing the secondary battery current control device 100, the current of the first secondary battery 80 or the second secondary battery 90 is periodically changed. The internal loss is reduced and the energy supply from the power storage device 120 inside the current control device to the load 50 is enabled, so that the discharge amount of the secondary battery 70 is suppressed and the discharge for one charge is performed. Time will be extended.

When the graph based on the simulation result shown in FIG. 7 is seen, the effect of extending the discharge time for one charge tends to increase as the capacity of the power storage device 120 or the power storage device 130 is increased. For example, an effect appears at 10F or more, and a more remarkable effect appears at 100F or more. Furthermore, the greater the value of the voltage V _{b1 of} the first secondary battery 80 and the voltage V _b2 of the second secondary battery 90, the greater the effect.

2.3 Description of Features of Example The relationship between the waveform of the current I _b1 flowing through the first secondary battery 80 illustrated in FIG. 3 and the current I _c1 flowing through the power storage device 120 illustrated in FIG. 4 will be examined. In the state shown in FIG. 1, the terminal 142 of the connection device 140 is on the terminal 146 side, and the power storage device 120 is connected in parallel with the first secondary battery 80. In this previous state, the power storage device 120 is electrically disconnected from the secondary battery 70, and the current at that time is indicated by the current _Ic1a in the graph of FIG. Absent. In this state, a large current for supplying the load 50 flows through the first secondary battery 80, as indicated by the current _Ib1a shown in FIG. It is considered that the capacity stored in the first secondary battery 80 decreases due to the current I _b1a flowing, and the terminal voltage V _{b1 of} the first secondary battery 80 decreases. On the other hand, since the current I _c1 does not flow in the power storage device 120, the capacity of the power storage device 120 is maintained, and the terminal voltage V _c1 of the power storage device 120 is also maintained without decreasing.

When the terminal 142 of the connection device 140 is switched to the terminal 144 side and the terminal 142 is connected to the power storage device 120, the power storage device 120 and the first secondary battery 80 are connected in parallel. First, large current I _c1b shown in FIG. 4 is temporarily released from power storage device 120 in accordance with the voltage difference between power storage device 120 and first secondary battery 80. This current flows into the first secondary battery 80, and temporarily charges the first secondary battery 80 as shown as current _{Ib1b in} FIG. Further, as shown in FIG. 1, although the first secondary battery 80 is connected to the load 50 in terms of an electric circuit, the voltage drop rate of the power storage device with respect to the discharge current and the internal resistance of the battery Due to the balance of the voltage drop rate due to, a continuous charging current can also flow from the power storage device 120 to the first secondary battery 80 as shown as the current _Ib2b . In addition to the effect of reducing the internal loss of the secondary battery due to the periodic change of the current of the first secondary battery 80 or the second secondary battery 90 and the energy supply from the power storage device 120, there is also a battery charging effect. Therefore, it is considered that the effect described with reference to FIG. 7 occurs.

The following can also be considered. In general, in a parallel connection circuit of a battery and a capacitor, a battery having a high internal resistance hardly flows current, and thus the current is biased to the capacitor. Considering a parallel circuit of the power storage device 120 and the first secondary battery 80 now, since the internal resistance of the power storage device 120 constituted by a capacitor is lower than that of the first secondary battery 80, the current I _c1 flowing through the power storage device 120 is the first. The current I _b1 flowing through the secondary battery 80 tends to flow more easily. When the capacity of the power storage device 120 is small, the current _Ic1 flows, so that the terminal voltage of the power storage device 120 rapidly decreases. However, when the capacity of the power storage device 120 is increased, for example, the capacity of the power storage device 120 is 10F or more, and further, the capacity of the power storage device 120 is 100F or more. As the capacity of the device 120 increases, the time constant of the terminal voltage decrease due to the current I _c1 of the power storage device 120 increases, and the terminal voltage decrease slows down. Since the power storage device 120 and the first secondary battery 80 are connected in parallel, the terminal voltage of the power storage device 120 and the terminal voltage of the first secondary battery 80 are kept equal, and thus the first secondary battery. It is necessary to raise the terminal voltage of 80. Therefore, the current I _c1 of the power storage device 120 flows into the first secondary battery 80 as the charging current of the first secondary battery 80. Such a phenomenon occurs, and this phenomenon contributes to the effect as shown in FIG.

Now, the relationship between the power storage device 120 and the first secondary battery 80 has been described. The current I _b2 flowing through the second secondary battery 90 and the current I _c2 flowing through the power storage device 130 shown in FIG. This is very similar to the relationship between the current I _b1 flowing through the secondary battery 80 and the current I _c1 flowing through the power storage device 120. Therefore, it is considered that the power storage device 130 has the same effect on the second secondary battery 90 as the power storage device 120 exerts on the first secondary battery 80 and has the same effect.

2.4 Explanation of other operational effects in the embodiment In the method described in Patent Document 1, the problem to be solved is improvement of the charge / discharge cycle life of the secondary battery. In the present invention, in effect and configuration, This is different from the known invention described in Patent Document 1. However, the embodiment shown in FIG. 1 has a further different effect. For example, the voltage difference between the terminals of the power storage device 120 and the first secondary battery 80 is small, and the voltage acting between the terminals of the connection device 140 is small. The same applies to power storage device 130 and second secondary battery 90. Therefore, the current flowing through the connecting device 140 is also small. The electrical load on the connection device 140 is small, and it is suitable for extending the life.

  The secondary battery 70 is connected to the load 50 in terms of circuit regardless of the operation of the connection device 140, and even if an abnormality occurs in the connection device 140, current is supplied from the secondary battery 70 to the load 50. It becomes possible to continue doing. Therefore, for example, when the load 50 is an emergency light, a traffic light, a vehicle drive device, or a device related to safety, there is an effect that safety is easily maintained. For example, even if the connection device 140 breaks down and remains in a state where it is connected to either of them, or even if it becomes difficult for the power storage device 120 or the power storage device 130 to connect to the secondary battery 70, it is immediately dangerous. However, the connection between the secondary battery 70 and the load 50 can be maintained, and the power supply from the secondary battery 70 to the load 50 can be maintained.

3. Description of Modification of Example In FIG. 1, a lithium ion secondary battery was used in the simulation as the first secondary battery 80 and the second secondary battery 90. However, not only lithium ion secondary batteries but also other types of batteries are considered to have an effect of extending the discharge time for these one-time charging. Further, in the simulation, capacitors were used as the power storage device 120 and the power storage device 130. However, the action of periodically changing the current flowing through the first secondary battery 80 and the second secondary battery 90 is not limited to the use of a capacitor, and the power storage device 120 and the power storage device 130 have a power storage function. The power storage device other than the capacitor, such as a secondary battery, is also possible.

  However, as shown in FIGS. 1 and 8, the use of a capacitor as the power storage device 120 or the power storage device 130 is superior to the use of a power storage device other than the capacitor, for example, a secondary battery. That is, the capacitor has a lower voltage drop with respect to the discharge current in the charge / discharge operation than the secondary battery or the like. For this reason, when connected in parallel with the secondary battery, it is easy to extract energy from the capacitor. Therefore, it is preferable to use a capacitor as an embodiment of the present invention from the viewpoint of the effect of the present invention.

  The secondary battery 70 includes a first secondary battery 80 and a second secondary battery 90 in this embodiment. However, as described above, only one of the first secondary battery 80 and the second secondary battery 90 may be used. Alternatively, more secondary batteries may be provided. It is important that an appropriate supply voltage is selected according to the type of load 50, and the number of serial secondary batteries included in the secondary battery 70 can be determined from the viewpoint of the supply voltage. The number of power storage devices 120 and power storage devices 130 is not limited to the example, and may be one or more power storage devices. When using components used as the power storage device 120 or the power storage device 130, for example, capacitors, each capacitor has a preferable voltage. It is desirable to determine the number of capacitors connected in series constituting the power storage device 120 or the power storage device 130 based on the relationship between the voltage used for each capacitor and the voltage across the secondary battery 70. Further, it is desirable to determine the number of capacitors connected in parallel that constitute power storage device 120 or power storage device 130 based on what value the capacity of power storage device 120 or power storage device 130 is set to.

  In the embodiment shown in FIG. 1 and FIG. 8 described below, the first secondary battery 80 and the second secondary battery 90 are secondary batteries having substantially the same characteristics from the viewpoint of operational stability. Are connected in series and in parallel by the same number. Although not shown, the power storage device 120 and the power storage device 130 are configured by connecting the same number of capacitors having substantially the same characteristics in series and in parallel.

  In the simulation, the connection between the power storage device 120 and the power storage device 130 is performed at intervals of one second, but the present invention is not limited to this cycle. For example, switching may be performed at intervals of 0.1 seconds, or switching may be performed at shorter intervals. Switching may be performed at longer intervals. For example, the interval may be 10 seconds or longer. When the interval becomes longer, for example, the voltage drop of the first secondary battery 80 becomes larger. For example, the terminal voltage between the power storage device 120 and the first secondary battery 80 when the power storage device 120 is connected to the first secondary battery 80 is increased. The difference becomes larger. However, the voltage drop of the first secondary battery 80 is determined by the relationship between the current supplied to the load 50 and the capacity of the first secondary battery 80, and the current supplied from the first secondary battery 80 to the load 50 is large. In addition, the voltage drop of the first secondary battery 80 increases. Although the first secondary battery 80 has been described above, the same applies to the second secondary battery 90. Therefore, the cycle of the switching operation of the connection device 140 may be changed based on the magnitude of the current supplied by the secondary battery 70. In this case, when the case where the supply current to the load 50 is large and the case where the supply current to the load 50 is small, switching is performed in a shorter cycle when the supply current to the load 50 is large.

  The control device 150 may have data representing the relationship between the supply current amount of the secondary battery 70 and the switching cycle of the connection device 140, and the control device 150 may control the switching cycle based on this data. . Alternatively, a change in the voltage between terminals of the first secondary battery 80 or the second secondary battery 90 or the like may be actually detected, and the control device 150 may control the switching cycle of the connection device 140 according to the detection result. As another idea, the current value flowing through the power storage device 120 or the power storage device 130 when the power storage device 120 or the power storage device 130 is connected is measured, and the connection device 140 is switched so that the current value falls within the set range. The period may be controlled.

4). 1. Description of Operation Related to Product to which the Present Invention is Applied While the power supply operation from the secondary battery 70 to the load 50 has been described with reference to FIG. 1, in an actual product, the secondary battery 70 is supplied from the power supply source. Power is stored in the secondary battery 70, and power for driving the load 50 is supplied from the secondary battery 70 based on the stored power. A power storage operation for storing electric power in the secondary battery 70 will be described with reference to FIG. Note that the same reference numerals as those in the other drawings indicate the same configuration, and perform substantially the same function and achieve substantially the same effect.

When the secondary battery current control device 100 is not provided, the first secondary battery 80 and the second secondary battery 90 are connected from the DC power supply 55 provided instead of the load 50 via the terminal 62 and the terminal 64. Is supplied with a direct current. The charging current _{I B1c} and current _{I b2c} supplied from the first secondary battery 80 and each direct current power source 55 to the second secondary battery 90 constituting the secondary battery 70. When the secondary battery current control device 100 is not provided, the charging current I _b1c and the current I _b2c have the same value.

Next, a secondary battery current control device 100 is provided, and the power storage device 120 and the power storage device 130 are alternately connected in parallel to the first secondary battery 80 and the second secondary battery 90 in a predetermined cycle by the operation of the connection device 140. Then, the current I _b1c and the current I _b2c are changed to a pulse-like current, that is, an intermittent current state. The operation of the connecting device 140 and the current I _b1c flowing through the first secondary battery 80 and the current I _c2c flowing through the second secondary battery 90 are examined.

Consider a state in which the terminal 142 and the terminal 146 of the connection device 140 are connected. In this state, the power storage device 120 is not connected. Therefore, current I _c1c of power storage device 120 does not flow. Since the secondary battery 70 and the DC power supply 55 are connected, the current I _b1c is supplied to the first secondary battery 80. Further, the current I _b2c flows through the second secondary battery 90, and the current I _c2c flows through the power storage device 130. When the current I _b1c flows, the storage amount of the first secondary battery 80 increases, and the terminal voltage V _{b1 of} the first secondary battery 80 increases. As a result, the terminal voltage V _{b1 of} the first secondary battery 80 becomes larger than the terminal voltage V _c1 of the power storage device 120. Since the current I _b2c and the current I _c2c also flow through the second secondary battery 90 and the power storage device 130, respectively, the terminal voltage V _b2 of the second secondary battery 90 and the terminal voltage V _c2 of the power storage device 130 increase. Since the secondary battery 90 and the power storage device 130 are connected in parallel with each other in a substantially short-circuited state, the terminal voltage V _b2 of the second secondary battery 90 and the terminal voltage V _c2 of the power storage device 130 are substantially the same value. Maintained.

Next, when the connection device 140 operates to connect the terminal 142 of the connection device 140 to the terminal 144 and release the terminal 146, the terminal voltage _{Vb1 of} the first secondary battery 80 becomes the terminal voltage V of the power storage device 120. Since it is larger than _c1 , the current _Ib1c has a value in the reverse direction and acts as a charging current for the power storage device 120. Current is supplied to the power storage device 120 from the DC power supply 55 and the first secondary battery 80, the amount of charge of the power storage device 120 increases, and the terminal voltage V _c1 of the power storage device 120 increases. When the terminal voltage V _c1 of the power storage device 120 becomes equal to the terminal voltage V _b1 of the first secondary battery 80, the current from the first secondary battery 80 to the power storage device 120 disappears, and the first secondary battery 80 from the DC power supply 55 is lost. And the power storage device 120 are supplied with charging current.

Since power storage device 130 is not connected, current I _c2c does not flow. As a result the terminal voltage _{V c2} of the power storage device 130 is not increased, since the second secondary battery 90 current _{I b2c} is supplied from the DC power source 55 terminal voltage _{V c2} of the second secondary battery 90 is increased. Next, when the terminal 142 of the connection device 140 is connected to the terminal 146 again, a charging current flows from the second secondary battery 90 to the power storage device 130. That is, a reverse current temporarily flows through the second secondary battery 90. Such an operation is performed every time the connection device 140 is switched. The current flowing through the first secondary battery 80 and the second secondary battery 90 not only changes in a pulse shape, but also a current in the reverse direction periodically flows.

  By using the current control device 100 for the secondary battery in this way, not only in a state where power is supplied to the load 50, but also in a state where charging power is supplied from the DC power supply 55 to the secondary battery 70, It is possible to control the current of the secondary battery 70 so as to change at a predetermined cycle like a pulse state, and it is possible to achieve the effect of improving the efficiency and extending the life. Furthermore, the current flowing through the secondary battery 70 can be controlled not only to change at a predetermined cycle, but also to change the direction of the current flowing through the secondary battery 70 at a predetermined cycle, so that a greater effect can be obtained. .

50 ... Load, 62 ... Terminal, 64 ... Terminal, 80 ... First secondary battery, 90 ... Second secondary battery, 120 ... Power storage device, 130 ... Power storage Device, 140... Connection device, 150... Control device.

Claims (7)

A secondary battery current control device that controls the current of a secondary battery that supplies power to a load,
The current control device includes: a power storage device that supplies current based on stored power; a connection device that connects the power storage device in parallel to the secondary battery; and a control device that controls a connection state of the connection device. Have
The control device operates the connection device in a predetermined cycle while the secondary battery is connected to the load, repeats the power storage device in a predetermined cycle, and connects in parallel to the secondary battery ,
Furthermore, the secondary battery has at least a first secondary battery and a second secondary battery connected in series,
Furthermore, the power storage device included in the current control device has at least a first capacitor and a second capacitor,
The connecting device repeatedly connects the first capacitor in parallel with the first secondary battery at a predetermined cycle, and repeatedly connects the second capacitor in parallel with the second secondary battery at a predetermined cycle. A current control device for a secondary battery. A secondary battery current control device that controls the current of a secondary battery that supplies power to a load,
The current control device includes: a power storage device that supplies current based on stored power; a connection device that connects the power storage device in parallel to the secondary battery; and a control device that controls a connection state of the connection device. Have
The control device operates the connection device in a predetermined cycle while the secondary battery is connected to the load, repeats the power storage device in a predetermined cycle, and connects in parallel to the secondary battery ,
A current control device for a secondary battery, wherein current is temporarily supplied from the power storage device to the secondary battery when the power storage device is connected in parallel to the secondary battery. The current control device for a secondary battery according to claim 1 ,
When the first capacitor or the second capacitor is connected to the first secondary battery or the second secondary battery, the terminal voltage of the first capacitor or the second capacitor is changed to the first secondary battery or A current control device for a secondary battery, wherein the current control device is larger than a terminal voltage of the second secondary battery. The secondary battery current control device according to any one of claims 1 to 3 ,
In addition to the state in which the secondary battery is connected to the load, the control device sets the connection device to a predetermined state even in a state in which the secondary battery is supplied with electric power from the outside and stores electric power. A secondary battery current control device, wherein the secondary battery is operated in a cycle, the power storage device is repeated in a predetermined cycle, and connected in parallel to the secondary battery. In the secondary battery current control device according to any one of claims 1 to 4 ,
The current control device for a secondary battery, wherein the control device is operated repeatedly at a cycle longer than 0.1 seconds. 6. The secondary battery current control device according to claim 1 , wherein the power storage device has a capacity of 10 Farads or more. 7. . The current control device for a secondary battery according to claim 6 , wherein the power storage device has a capacity of 100 Farad or more.

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