Patent Description:
In recent years, efforts have been made to reuse battery packs that had been mounted on a vehicle. Since there is a problem that such efforts are unprofitable when the battery pack is dismantled into cells and modules, the battery pack is reused as it is.

However, a battery pack using small lithium ion batteries has a small battery capacity, and therefore cannot be used as it is for household power. Against this background, one reuse application of a battery pack using small lithium ion batteries is a streetlight electric storage device. Further, the streetlight may be a solar-type streetlight (hereinafter referred to as a "solar streetlight").

Performance such as capacity and internal resistance of a battery pack collected from the market is deteriorated as compared to a new battery pack, and performance varies among battery packs. In consideration of such circumstances, it is necessary to increase the capacity by combining a plurality of battery packs when reusing battery packs.

<CIT> discloses a storage battery control device aimed to, when an anomaly occurs due to a disaster such as an earthquake, a tsunami, wind and flood damage, or fire, discharge electricity stored in a storage battery and reduce the possibility of a secondary disaster compared with prior art. The storage battery control device includes an electricity control unit that, when it is determined that an anomaly has occurred on the basis of a signal received from an anomaly detection unit, causes an electricity consumption unit to consume electricity stored in the storage battery and lowers the electricity amount of the storage battery to equal to or less than a set charge amount.

<CIT> discloses that the anomaly detection unit is an immersion sensor that detects presence or absence of water immersion. According to such a configuration, the storage battery control device described in <CIT> can detect anomaly due to water immersion, and can discharge the storage battery before an electricity storage system is damaged by water immersion.

However, the storage battery control device described in <CIT> has a problem that information on water immersion (hereinafter referred to as "immersion information") cannot be recognized outside the electricity storage system.

The present invention has been made in view of the foregoing, and aims to provide an electric storage device that can give notification of immersion information to the outside.

In order to achieve the above objective, the present invention is an electric storage device as defined in the appended independent claim <NUM>.

According to the present invention, it is possible to provide an electric storage device that can give notification of immersion information to the outside.

An electric storage device according to an embodiment of the present invention is characterized by including: a plurality of battery packs capable of supplying electricity to a predetermined load, and installed to align in an up-down direction inside a columnar member; a control device that is arranged above the battery packs and controls the battery packs; a submersion sensor provided in each of the plurality of battery packs; and a notification unit that gives notification of information regarding immersion to the outside, in which the control device includes a communication unit that receives information indicating submersion from the submersion sensor in each battery pack, a determination unit that determines a degree of immersion on a basis of which of the submersion sensors having transmitted the received information indicating submersion, and a control unit that controls the notification unit to give notification of immersion degree information indicating the degree of immersion determined by the determination unit to the outside. With this configuration, the electric storage device according to the embodiment of the present invention can give notification of immersion information to the outside.

Hereinafter, an electric storage device according to an example of the present invention will be described with reference to the drawings.

As illustrated in <FIG>, the present example is described by using an electric storage device used for a solar streetlight installed outside as an example.

A solar streetlight <NUM> as a streetlight includes a columnar member <NUM>, a solar panel <NUM>, an illumination device <NUM> as a predetermined load, a plurality of battery packs <NUM>, and a control device <NUM>. The solar streetlight <NUM> is installed on a ground G.

Hereinafter, based on the columnar member <NUM>, the illumination device <NUM> side is defined as "front," the opposite side thereof is defined as "back," when viewing the front side from the back side, the left side is defined as "left," the right side is defined as "right," and the upper side is defined as "up. " Of the side surfaces of the columnar member <NUM>, a side surface on which the illumination device <NUM> is installed is the front side of the solar streetlight <NUM>.

The columnar member <NUM> is formed of a square pole, and is formed in a hollow shape having a space on the inside. The columnar member <NUM> can also adopt shapes other than the square pole, such as a prism or a cylinder. As will be described later, a plurality of battery packs <NUM> capable of supplying electricity to the illumination device <NUM> and the control device <NUM> are installed inside the columnar member <NUM>.

The control device <NUM> is disposed above the plurality of battery packs <NUM> inside the columnar member <NUM>. A first opening <NUM> and a second opening <NUM> located above the first opening <NUM> are formed on a side surface 2a on the front side of the columnar member <NUM>.

The first opening <NUM> is provided in the installation position of the plurality of battery packs <NUM>. The first opening <NUM> is used when performing work such as replacing the battery pack <NUM> and performing maintenance, for example, and is closed by a lid 21a when the work is not performed.

The second opening <NUM> is provided in the installation position of the control device <NUM>. The second opening <NUM> is used when operating the control device <NUM> or performing maintenance work, for example, and is closed by a lid 22a when the operation and work are not performed.

In the present example, the installation area of the plurality of battery packs <NUM> inside the columnar member <NUM> is longer than the installation area of the control device <NUM> in the height direction of the columnar member <NUM>, and therefore the first opening <NUM> is longer than the second opening <NUM> in the height direction.

A drainpipe <NUM> embedded below the ground G is connected to a bottom part of the columnar member <NUM>. The drainpipe <NUM> is a pipe for draining moist that pools in the bottom part of the columnar member <NUM> to the underground as wastewater.

The solar panel <NUM> is attached to a top <NUM> of the columnar member <NUM>. The solar panel <NUM> is formed of a photovoltaic module that generates electricity using optical energy from the sun, and is adjusted according to the installation location of the solar streetlight <NUM>, so that the solar panel <NUM> is oriented to obtain the maximum amount of solar radiation throughout the year. The solar panel <NUM> is connected to the battery pack <NUM> and the control device <NUM> to be able to supply electricity thereto.

The illumination device <NUM> is disposed in an upper part of the side surface 2a on the front side of the columnar member <NUM>, and shines a downward light from an upper part of the columnar member <NUM>.

The battery pack <NUM> is a reused vehicle battery pack that had been mounted on a vehicle. In the present example, in order to reuse battery packs with a small capacity used in hybrid vehicles, a plurality of battery packs <NUM> are combined to increase the capacity for use.

In the case of reused battery packs <NUM>, performance varies due to different capacities and degrees of deterioration in internal resistance and the like depending on the usage history. Since the remaining life differs among the plurality of combined battery packs <NUM>, there is a high possibility that the battery pack <NUM> will need to be replaced during use. In the present example, by arranging the plurality of battery packs <NUM> inside the columnar member <NUM> as described above, even when an anomaly occurs in some battery packs <NUM>, operation as a streetlight can be assured by the remaining battery packs <NUM>.

The battery pack <NUM> is formed in a rectangular parallelepiped shape in which a side in the vertical direction is shorter than a side in the horizontal direction when placed in the transverse direction. "Placed in the transverse direction" refers to how the battery pack <NUM> is placed when mounted on a vehicle, and is how the battery pack <NUM> is placed so that its thickness is minimized.

In the present example, the battery pack <NUM> is mounted so as to be placed in the vertical direction inside the columnar member <NUM>. Moreover, in the present example, the vertically placed plurality of battery packs <NUM> are arranged to align in the up-down direction inside the columnar member <NUM>.

The plurality of battery packs <NUM> arranged in the up-down direction inside the columnar member <NUM> form a battery pack group. In the present example, five battery packs <NUM> arranged in the up-down direction form one battery pack group. The number of battery packs <NUM> included in a battery pack group is arbitrary, and is not limited to five.

Moreover, in the present example, two rows of the battery pack groups are provided inside the columnar member <NUM>. Of the two rows of battery pack groups, one is referred to as a battery pack group 5A, and the other is referred to as a battery pack group 5B. The number of rows of the battery pack groups provided inside the columnar member <NUM> is not limited to two, and may be one, or three or more, for example.

The battery packs <NUM> of the same battery pack group are connected to the same wiring. Specifically, the five battery packs <NUM> included in the battery pack group 5A are connected to wiring 50A, and the five battery packs <NUM> included in the battery pack group 5B are connected to wiring 50B.

The wiring 50A and the wiring 50B are routed in the up-down direction inside the columnar member <NUM>.

A positive terminal <NUM> and a power supply terminal <NUM> described later of each battery pack <NUM>, the solar panel <NUM>, the illumination device <NUM>, the control device <NUM>, and the like of the corresponding battery pack group are connected to each of the wiring 50A and the wiring 50B.

The battery pack group 5A and the battery pack group 5B form different battery pack group systems, and can function independently. For this reason, even when a trouble occurs in one system, the battery pack can be operated by the other system in which no trouble has occurred.

The control device <NUM> is connected to a battery management system (BMS) <NUM> (see <FIG>) described later in the battery pack <NUM>, and controls the plurality of battery packs <NUM> via the BMS <NUM>. The control device <NUM> exchanges information with the BMS <NUM> through communication.

The control device <NUM> is formed of a computer unit including a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), an input port, and an output port. A program for causing the computer unit to function as the control device <NUM> is stored, together with various constants and the like, in the ROM of the computer unit. That is, the CPU executing the program stored in the ROM by using the RAM as a work area causes the computer unit to function as the control device <NUM> of the present example.

Various sensors <NUM> (see <FIG>) are connected to the control device <NUM>. For example, sensors capable of detecting a change in the external environment such as an illumination sensor are connected to the control device <NUM>. The control device <NUM> may include a timer that manages the lighting duration and lighting time. A configuration of the control device <NUM> will be described in detail later.

Next, the electric configuration of the battery pack <NUM> of the present example will be described with reference to <FIG>.

As illustrated in <FIG>, the battery pack <NUM> includes a battery <NUM>, a relay <NUM>, a BMS <NUM>, and a submersion sensor <NUM>. The battery <NUM>, the relay <NUM>, the BMS <NUM>, and the submersion sensor <NUM> are provided inside the battery pack <NUM>.

The battery <NUM> is formed of a chargeable and dischargeable secondary battery such as a lithium ion battery. The battery <NUM> has a positive electrode 53a and a negative electrode 53b.

The positive electrode 53a of the battery <NUM> is connected to the positive terminal <NUM> via the relay <NUM> so as to be electrically conductive. The positive terminal <NUM> is a terminal that outputs the voltage of the battery <NUM> to the outside of the battery pack <NUM>, and is exposed to the outside of the battery pack <NUM>. The negative electrode 53b of the battery <NUM> is connected to a case of the battery pack <NUM> via a ground terminal <NUM>.

The relay <NUM> is a switch that is provided between the positive electrode 53a of the battery <NUM> and the positive terminal <NUM>, and is capable of switching between a connected state in which the positive electrode 53a of the battery <NUM> and the positive terminal <NUM> are connected and a disconnected state in which the two are disconnected.

The relay <NUM> is switched to the disconnected state when submersion of the battery pack <NUM> is detected by the submersion sensor <NUM>.

The BMS <NUM> monitors and manages states of the battery <NUM> such as the voltage value and the state of charge (SOC) of the battery <NUM>. The BMS <NUM> calculates the SOC on the basis of the charging and discharging current of the battery <NUM>. The BMS <NUM> controls switching between the connected state and disconnected state of the relay <NUM>.

The BMS <NUM> is connected to the control device <NUM> through a communication terminal <NUM> provided in the battery pack <NUM>. The BMS <NUM> is connected to the power supply via the power supply terminal <NUM> and a power supply GND terminal <NUM> provided in the battery pack <NUM>. In the present example, the battery <NUM> and the solar panel <NUM> are used as the power supply.

The submersion sensor <NUM> is a sensor that detects submersion of the battery pack <NUM>. Various submersion sensors such as a sensor that detects submersion by sensing hydraulic pressure of a predetermined pressure or greater indicating submersion, a sensor that detects submersion when positive and negative terminals are submerged in water and there is continuity between the terminals, or the like can be used as the submersion sensor <NUM>.

Here, the battery pack <NUM> is installed in the vertical direction inside the columnar member <NUM> to be oriented so that the positive terminal <NUM> is located above the submersion sensor <NUM>. As a result, the positive terminal <NUM> is located above the submersion sensor <NUM>.

Next, a configuration of the control device <NUM> of the present example will be described with reference to <FIG>.

As illustrated in <FIG>, the control device <NUM> has a function as a communication unit <NUM> that receives information indicating submersion from the submersion sensor <NUM> in each battery pack <NUM>. The control device <NUM> has a function as a determination unit <NUM> that determines the degree of immersion on the basis of which of the submersion sensors <NUM> in the battery packs <NUM> having transmitted the received information indicating submersion.

Here, the ROM of the control device <NUM> stores, for each battery pack <NUM>, the height from the ground G to the installation position of the battery pack <NUM> as height information. The control device <NUM> can identify the battery pack <NUM> including the submersion sensor <NUM> from which the information indicating submersion has been received, and determine the degree of immersion by referring to the height information of the identified battery pack <NUM>. That is, the control device <NUM> can determine up to what height (how many meters) the solar streetlight <NUM> is immersed in water.

The control device <NUM> has a function as a control unit <NUM> that controls a notification unit <NUM> described later to give notification of immersion degree information indicating the degree of immersion determined by the determination unit <NUM> to the outside. Immersion degree information is information indicating the immersion height of the solar streetlight <NUM> in its installation location.

The notification unit <NUM> that gives notification of information regarding immersion to the outside is connected to the control device <NUM>. The notification unit <NUM> is formed of an analog, digital, or another-type indicator, and is provided on an outer surface of the columnar member <NUM>. With this configuration, the control device <NUM> can display the immersion height of the solar streetlight <NUM> in its installation location on the indicator.

The outer surface of the columnar member <NUM> on which the notification unit <NUM> is provided is preferably the side surface 2a on the front side of the columnar member <NUM>, for example. In this case, in order for the notification unit <NUM> to give notification to a wider area, it is desirable that the notification unit <NUM> be provided in an upper part of the side surface 2a on the front side of the columnar member <NUM>.

Next, the electrical connection of the solar streetlight <NUM> of the present example will be described with reference to <FIG>.

As illustrated in <FIG>, one to n (n = <NUM> in present example) battery packs <NUM> are provided in the solar streetlight <NUM> according to the present example. In the present example, in order to distinguish among the plurality of battery packs <NUM>, the plurality of battery packs <NUM> are denoted by battery packs <NUM>(<NUM>) to <NUM>(n). When referring to one battery pack without specifying which of the battery packs <NUM>(<NUM>) to <NUM>(n), the battery pack is simply referred to as the "battery pack <NUM>.

In <FIG>, the battery pack <NUM> of the battery pack group 5A connected to the wiring 50A is illustrated as an example of the battery packs <NUM>(<NUM>) to <NUM>(n). Hence, the wiring 50B and the battery pack group 5B are omitted from <FIG>.

The battery packs <NUM>(<NUM>) to <NUM>(n) are connected in parallel to each other with respect to the wiring 50A.

In the present example, to identify which of the battery packs <NUM>(<NUM>) to <NUM>(n) the battery <NUM>, the relay <NUM>, and the BMS <NUM> belong to, the batteries <NUM>, the relays <NUM>, and the BMSs <NUM> corresponding to the battery packs <NUM>(<NUM>) to <NUM>(n) are denoted by batteries <NUM>(<NUM>) to <NUM>(n), relays <NUM>(<NUM>) to <NUM>(n), and BMSs <NUM>(<NUM>) to <NUM>(n). Regarding the batteries <NUM>(<NUM>) to <NUM>(n), the relays <NUM>(<NUM>) to <NUM>(n), and the BMSs <NUM>(<NUM>) to <NUM>(n), when referring to one battery, relay, and BMS without specifying which of the battery packs <NUM>(<NUM>) to <NUM>(n) the components belong to, the components are simply referred to as the "battery <NUM>," the "relay <NUM>," and the "BMS <NUM>.

A first switch <NUM> capable of switching between an ON state in which the BMS <NUM> and the wiring 50A are connected and an OFF state in which the two are disconnected is provided between the BMS <NUM> and the wiring 50A. At least one first switch <NUM> is provided for each BMS <NUM>. While the present example describes an example in which one first switch <NUM> is provided for each BMS <NUM>, two or more first switches <NUM> may be provided for each BMS <NUM>.

In the present example, to identify which of the BMSs <NUM>(<NUM>) to <NUM>(n) the first switch <NUM> belongs to, the first switches <NUM> corresponding to the BMSs <NUM>(<NUM>) to <NUM>(n) are denoted by first switches <NUM>(<NUM>) to <NUM>(n). Regarding the first switches <NUM>(<NUM>) to <NUM>(n), when referring to one switch without specifying which of the BMSs <NUM>(<NUM>) to <NUM>(n) the switch belongs to, the switch is simply referred to as the "first switch <NUM>.

The control device <NUM> controls the switching between the ON state and the OFF state of the first switch <NUM>.

A second switch <NUM> is connected to one end of the wiring 50A. The second switch <NUM> is a switch that is provided between the wiring 50A, and the solar panel <NUM> and illumination device <NUM>, and is capable of switching between an ON state in which the wiring 50A and the solar panel <NUM> or illumination device <NUM> are connected and an OFF state in which the two are disconnected.

That is, the second switch <NUM> is capable of switching between an ON state which is either a power generation-ON state connecting the wiring 50A and the solar panel <NUM> or a discharge-ON state connecting the wiring 50A and the illumination device <NUM>, and an OFF state not connecting the wiring 50A with any of the solar panel <NUM> and the illumination device <NUM>.

The control device <NUM> controls the switching between the power generation-ON state or discharge-ON state and the OFF state of the second switch <NUM>. In a state where the power of the control device <NUM> is not turned on, such as at the time of initial startup of the solar streetlight <NUM>, from the viewpoint of ensuring electricity for starting the solar streetlight <NUM>, it is preferable that the second switch <NUM> be switched to the power generation-ON state.

The control device <NUM> is connected to the wiring 50A, and receives supply of electricity from at least one of the solar panel <NUM> and the battery packs <NUM>(<NUM>) to <NUM>(n) via the wiring 50A. The control device <NUM> controls switching between the ON state and the OFF state of the first switch <NUM> and the second switch <NUM>.

In the present example, the battery packs <NUM> are arranged from top to bottom in the order of the battery packs <NUM>(<NUM>) to <NUM>(n) inside the columnar member <NUM>. The first switch <NUM> is arranged above the relay <NUM>.

Next, an operation of the solar streetlight <NUM> when an installation location of the solar streetlight <NUM> is flooded will be described. In the solar streetlight <NUM> configured as described above, when an installation location of the solar streetlight <NUM> is flooded, the following operation is performed.

For example, when the submersion sensor <NUM> of the battery pack <NUM>(n) detects submersion in a state where the battery pack <NUM>(n) is supplying electricity, the first switch <NUM>(n-<NUM>) of the battery pack <NUM>(n-<NUM>) arranged immediately above the battery pack <NUM>(n) is switched to the ON state.

After the first switch <NUM>(n-<NUM>) is switched to the ON state, the relay <NUM>(n-<NUM>) is switched to the connected state. Thereafter, the relay <NUM>(n) of the battery pack <NUM>(n) is switched to the disconnected state.

When the relay <NUM>(n) is switched to the disconnected state, the first switch <NUM>(n) is switched to the OFF state.

By operating the solar streetlight <NUM> in the above procedure, it is possible to prevent interruption of the electricity supply from the battery pack <NUM>. Additionally, even when some battery packs <NUM> are submerged in water, the remaining battery packs <NUM> can be used to continue lighting by the illumination device <NUM>.

The control device <NUM> is installed above the uppermost battery pack <NUM>(<NUM>), and therefore can maintain the electricity supply from the battery pack <NUM> and continue lighting by the illumination device <NUM> until all of the battery packs <NUM> are submerged in water.

Additionally, as described above, when the installation location of the solar streetlight <NUM> is flooded, the submersion sensors <NUM> in the battery packs <NUM> are sequentially activated from the lowermost battery pack <NUM> to the uppermost battery pack <NUM> installed inside the columnar member <NUM>.

In this case, as described above, since the control device <NUM> is installed above the battery pack <NUM>, the control device <NUM> is able to operate as long as the control device <NUM> is not submerged in water even when all the battery packs <NUM> are submerged in water. Accordingly, the control device <NUM> can grasp whether or not all of the battery packs <NUM> are submerged in water.

On the basis of height information of the battery pack <NUM> from which information indicating submersion is received, the control device <NUM> determines up to what height (how many meters) the solar streetlight <NUM> is immersed in water, and gives notification of immersion degree information to the outside via the notification unit <NUM>.

When receiving information indicating submersion from the submersion sensor <NUM> of a certain battery pack <NUM> among the plurality of battery packs <NUM> belonging to the same battery pack group, if information indicating submersion is not received from the submersion sensor <NUM> of the battery pack <NUM> lower than the battery pack <NUM> that has detected submersion, the control device <NUM> determines that an anomaly has occurred in the submersion sensor <NUM> that has transmitted the information indicating submersion.

Note that the control device <NUM> may determine whether the submersion sensor <NUM> having transmitted the information indicating submersion is normal or abnormal by a majority rule regarding the state of reception from submersion sensors <NUM> including the submersion sensors <NUM> of the battery packs <NUM> lower than the battery pack <NUM> that has detected submersion.

When receiving information indicating submersion from the submersion sensor <NUM> of a certain battery pack <NUM> belonging to one battery pack group among a plurality of battery pack groups, if no information indicating submersion has been received from the battery pack <NUM> belonging to another battery pack group at the same height as the battery pack <NUM> that has detected submersion, the control device <NUM> determines that an anomaly has occurred in the submersion sensor <NUM> that has transmitted the information indicating submersion.

Note that the control device <NUM> may determine whether the submersion sensor <NUM> having transmitted the information indicating submersion is normal or abnormal by a majority rule regarding the state of reception from submersion sensors <NUM> including the submersion sensors <NUM> of the battery packs <NUM> at the same height as the battery pack <NUM> that has detected submersion but belonging to another battery pack group.

As has been described, in the electric storage device according to the present example, the control device <NUM> determines the degree of immersion on the basis of which submersion sensor <NUM> has transmitted information indicating submersion, and controls the notification unit <NUM> to give notification of immersion degree information indicating the determined immersion degree to the outside. Thus, the electric storage device can give notification of immersion information to the outside.

In the electric storage device according to the present example, since the notification unit <NUM> is an indicator provided on the side surface 2a on the front side of the columnar member <NUM>, it is possible to give notification of the immersion degree information to the outside, such as to the periphery of the solar streetlight <NUM>, by the solar streetlight <NUM> alone. For this reason, it is possible to warn a driver of a vehicle present in the periphery of the solar streetlight <NUM> not to enter an area near the flooded installation location of the solar streetlight <NUM>.

Note that while the notification unit <NUM> is formed of an indicator in the present example, the invention is not limited thereto, and the notification unit <NUM> may be formed of the illumination device <NUM>. In this case, it is possible to notify a driver of a vehicle present in the periphery of the solar streetlight <NUM> of the flooded state by a blinking pattern or blinking cycle of the illumination device <NUM>. For example, the control device <NUM> shortens the blinking cycle when many battery packs <NUM> have detected submersion. Alternatively, at the time of a flood, the illumination device <NUM> may be lit in a color other than the illumination color used as lighting at times other than a flood. Moreover, a red light, for example, may be provided in the illumination device <NUM>, and the red light may be lit to give notification of the flooded state. By forming the notification unit <NUM> by the illumination device <NUM> as described above, immersion degree information can be notified using the illumination device <NUM>, so that no separate indicator is required, and the configuration can be simplified.

Alternatively, the notification unit <NUM> may be formed of a communication device that transmits immersion degree information to the outside. In this case, it is possible to notify a facility that needs to monitor the flooded state from a location away the solar streetlight <NUM> of the flooded state around the installation location of the solar streetlight <NUM>, and promptly report the flooded state to the local government or the like. The local government or the like can promptly take necessary measures against the flood.

Claim 1:
An electric storage device comprising:
a plurality of battery packs (<NUM>) configured to be capable of supplying electricity to a predetermined load (<NUM>), and installed to align in an up-down direction inside a columnar member (<NUM>);
a control device (<NUM>) configured to be arranged above the battery packs (<NUM>) and configured to control the battery packs (<NUM>);
a submersion sensor (<NUM>) configured to be provided in each of the plurality of battery packs (<NUM>); and
a notification unit (<NUM>) configured to give notification of information regarding immersion to the outside, the electric storage device being characterized in that
the control device (<NUM>) includes:
a communication unit (<NUM>) configured to receive information indicating submersion from the submersion sensor (<NUM>) in each battery pack (<NUM>),
a determination unit (<NUM>) configured to determine a degree of immersion on a basis of which of the submersion sensors (<NUM>) having transmitted the received information indicating submersion, and
a control unit (<NUM>) configured to control the notification unit (<NUM>) to give notification of immersion degree information indicating the degree of immersion determined by the determination unit (<NUM>) to the outside, wherein
the predetermined load (<NUM>) is an illumination device (<NUM>) used for a streetlight and the notification unit (<NUM>) is formed of the illumination device (<NUM>) provided on an outer surface (2a) of the columnar member (<NUM>).