JP2017147898A - Electricity storage device and micro battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electricity storage device capable of always achieving high conversion efficiency in the entire electricity storage device even when a plurality of battery modules are used, and a micro battery.SOLUTION: An electricity storage device 1X includes a charge/discharge instruction unit 20 instructing charge and discharge to each of micro batteries 10X. Each of the micro batteries 10X includes: a battery module 11; an individual power conversion unit 12 converting DC power charged and discharged by the battery module 11; and an individual charge/discharge control unit 13 controlling charge and discharge of the battery modules 11 according to the instruction of the charge/discharge instruction unit 20. The charge/discharge instruction unit 20 instructs the individual charge/discharge control unit 13 such that the number of the battery modules 11 that simultaneously perform charge or discharge is small.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power storage device including a plurality of micro batteries each having a battery module for charging and discharging DC power, and a micro battery constituting the power storage device.

  In recent years, in order to store electric power generated by solar power generation or to perform peak shift of electric power load, power storage devices that store electric power are often installed in houses and other facilities. . Such a power storage device includes at least one battery module configured by connecting at least one battery cell (unit cell) that charges and discharges DC power.

  The battery module deteriorates with repeated charging and discharging, and the discharge capacity gradually decreases. Therefore, a battery user who uses the power storage device needs to replace the battery module when the discharge capacity of the battery module decreases and the operation of the power storage device is hindered.

  The used battery module removed from the power storage device by replacement can be charged and discharged although the discharge capacity is reduced as compared with the new battery module. Therefore, for other battery users, even a used battery module may still be fully usable. Further, from the viewpoint of effectively using resources and reducing waste, used battery modules should be reused as much as possible.

  Therefore, Patent Document 1 proposes a power storage device for facilitating control after replacement of a battery module and reuse of a used battery module. Specifically, Patent Document 1 proposes a power storage device including a device control unit that performs various controls of a battery module based on information acquired from each of a plurality of battery modules.

JP 2014-187738 A

  By the way, electric power supplied from a power generation device such as a solar cell and electric power consumed by a load have a large temporal fluctuation. For this reason, the power that should be charged and discharged by the battery module also varies with time. However, the power conversion unit (inverter or converter) provided in the power storage device does not necessarily operate with high efficiency regardless of the amount of input or output power, and in some cases the efficiency is extremely high. This is a problem because it decreases (a lot of energy is lost due to heat loss, etc.).

  This problem will be specifically described with reference to the drawings. FIG. 6 is a graph illustrating an example of conversion characteristics of a general power conversion unit. In the graph shown in FIG. 6, the horizontal axis represents the input power converted by the power conversion unit, and the vertical axis represents the conversion efficiency of the power conversion unit.

  As shown in FIG. 6, in the general power conversion unit, when the input power increases to a certain extent (becomes a high efficiency conversion range), the conversion efficiency of the power conversion unit is stabilized at the maximum value or a value in the vicinity thereof. On the contrary, when the input power is reduced (becomes a low efficiency conversion range), the conversion efficiency of the power conversion unit is greatly reduced. Although FIG. 6 illustrates a graph in which the horizontal axis is input power, the outline of the graph is shown in FIG. 6 even when the horizontal axis is output power, input current, output current, and the like. It will be the same. Various rated values (rated input power, rated output power, rated conversion efficiency, etc.) in the power conversion unit are defined as conditions when the power conversion unit operates in the high efficiency conversion range. Specifically, the rated conversion efficiency is defined as the maximum value of the conversion efficiency in the high efficiency conversion range or a stable value in the vicinity thereof.

  The power storage device proposed in Patent Document 1 has a configuration including a plurality of battery modules and a common and one inverter that converts DC power charged and discharged by these battery modules. Therefore, in the power storage device, a large-sized inverter having a large convertible input power (inverter capacity) is required to cope with the case where all the battery modules are charged and discharged at the same time and with the maximum power. However, the conversion characteristics of such large inverters are particularly low in conversion efficiency when the input power is small compared to the conversion characteristics of general small inverters (for example, the conversion characteristics of large inverters are The high-efficiency conversion range in FIG. 6 shifts in the direction in which the input power increases, and the low-efficiency conversion range expands along the axial direction of the input power).

  Therefore, the power storage device proposed in Patent Document 1 has a problem that the conversion efficiency of the inverter is remarkably lowered when the power charged and discharged in the entire battery module is small.

  Therefore, an object of the present invention is to provide a power storage device and a microbattery that can be efficiently charged and discharged even if a plurality of battery modules are provided.

  In order to achieve the above object, the present invention provides a power storage device including a plurality of micro batteries that are electrically connected to a common power line, and charging / discharging instructing charging and discharging of each of the micro batteries. Each of the microbatteries includes a battery module that charges and discharges DC power, converts DC power discharged by the battery module, outputs power to the power line, and is input from the power line. An individual power conversion unit that converts electric power into direct-current power that is charged by the battery module, and an individual charge / discharge control unit that controls charging and discharging of the battery module according to instructions of the charge / discharge instruction unit, The charge / discharge instruction unit is configured to charge and release the battery module included in each of the micro batteries. The determined individually, to provide a power storage apparatus characterized by instructing the individual charging and discharging control unit, each comprising of the microbattery.

  According to this power storage device, since each of the microbatteries includes the individual power conversion unit, it corresponds to a case where all the battery modules charge and discharge at the same time and with maximum power as provided in the conventional power storage device. For this reason, a large-sized power conversion unit can be eliminated. Further, since the charge / discharge instruction unit individually determines charging and discharging of the battery modules included in each of the micro batteries, charging and discharging appropriate battery modules as necessary, and charging and discharging unnecessary battery modules. Discharge can be prevented.

  In the above power storage device, it is preferable that the charge / discharge instruction unit instructs the individual charge / discharge control unit to reduce the number of the battery modules that are charged or discharged simultaneously.

  According to this power storage device, since it is necessary to charge or discharge a few battery modules when it is necessary to charge or discharge a specific amount of power in the whole battery module, it is inevitably necessary to charge one battery. The DC power that the module charges or discharges increases. Thereby, in a microbattery provided with a battery module that performs charging or discharging, the power that is converted by the individual power conversion unit increases, so that the conversion efficiency in the individual power conversion unit can be constantly increased.

  Further, in the above power storage device, each of the microbatteries includes the battery module having the ability to charge and discharge the minimum DC power for achieving the rated conversion efficiency in the individual power conversion unit. preferable.

  Alternatively, in the above power storage device, each of the microbatteries includes the battery module having the ability to charge and discharge the minimum DC power for maximizing the conversion efficiency in the individual power conversion unit. preferable.

  According to these power storage devices, by realizing an appropriate combination of the battery module and the individual power conversion unit, a situation occurs in which the conversion efficiency in the individual power conversion unit is not sufficiently improved even by the control of the charge / discharge instruction unit. Can be prevented.

  In the above power storage device, it is preferable that the charge / discharge instruction unit instructs the individual charge / discharge control unit to preferentially charge and discharge the battery module that is not deteriorated.

  According to this power storage device, it is possible to level the uneven deterioration of the battery modules, which is a harmful effect that can be caused by reducing the number of battery modules that are charged or discharged simultaneously. Thereby, it is possible to slow down the decrease in the apparent discharge capacity of the power storage device (the overall discharge capacity of the battery module).

  Note that a control policy of preferentially charging and discharging a battery module that is not deteriorated and a control policy of reducing the number of battery modules that are charged or discharged are basically compatible. However, in the special case where the control policies of both compete (for example, when the variation in the charge / discharge performance of the battery module is extremely large, in order to minimize the number of battery modules to be charged or discharged, the most deteriorated Assuming that the battery module needs to be charged or discharged), it may be determined in advance which control policy is to be prioritized. In addition, other control policies (for example, a control policy for preferentially charging a battery module included in a microbattery that can also be used in other power consuming devices as described later) should be given priority. The order may be determined in advance.

  Further, in the above power storage device, each of the micro batteries further includes a data recording unit that records device data including information indicating a deterioration state of the battery module, and the charge / discharge instruction unit includes the micro battery. It is preferable to recognize the deterioration state of the battery module included in each of the micro batteries by acquiring the device data from the data recording unit included in each.

  According to this power storage device, for example, it is past deterioration of a battery module that the charge / discharge instruction unit is not aware of, such as a deterioration state of a battery module included in a used micro battery that has been used in another power storage device in the past. In addition, the charge / discharge instruction unit can be recognized.

  Further, in the above power storage device, at least one of the micro batteries has the battery module, the individual power conversion unit, and the individual charge / discharge control unit integrated therein, and is integrally attached to and detached from the power line. It is preferable that it is free.

  According to this power storage device, even if it becomes necessary to change the discharge capacity of the power storage device at a later time, the discharge capacity and power conversion capacity of the entire power storage device can be increased or decreased only by increasing or decreasing the number of micro batteries constituting the power storage device. Both can be increased or decreased to maintain a state where both are compatible. Therefore, it is possible to easily change the configuration of the power storage device.

  Further, in the above power storage device, the power supply device is detachable from the power line and the power consumption device other than the power storage device, and supplies power to the power consumption device when attached to the power consumption device. When a microbattery is connected to the power line to form the power storage device, the charge / discharge instruction unit controls the individual charge / discharge control so that the battery module included in the microbattery is preferentially charged. It is preferable to instruct the part.

  According to this power storage device, it is possible to preferentially use a microbattery that can be used in other power consuming devices other than the power storage device (for example, electric motorcycles, power tools, portable power supplies, etc.). Therefore, the convenience of the other power consuming device can be improved.

  Basically, the control policy of preferentially charging the battery modules included in the microbattery that can be used in other power consuming devices and the control policy of reducing the number of battery modules that are charged or discharged are compatible. To do. However, in special cases where the control policies of the two compete (for example, when the variation in charge / discharge performance of battery modules is extremely large, in order to minimize the number of battery modules to be charged, other power consuming devices However, it may be determined in advance which control policy is prioritized on the assumption that a battery module included in another microbattery, not a microbattery that can be used, needs to be charged. In addition, other control policies (for example, the control policy that preferentially charges and discharges battery modules that are not deteriorated as described above) are determined in advance. Also good.

  Further, in the above power storage device, the power line is configured to be interconnected to a commercial power system, and each of the individual power conversion units is connected to the power line. A single operation state detection device that outputs an active signal for detecting a power failure is provided, and the charge / discharge instruction unit is connected to the individual charge / discharge control unit included in any one of the micro batteries. It is preferable that only the individual power conversion unit included in is instructed to output the active signal.

  According to this power storage device, problems such as a decrease in the accuracy of detection of an isolated operation state due to interference of an active signal or an adverse effect of an active signal on power supplied from a commercial power system arise. Can be prevented.

  In the above power storage device, the individual charge / discharge control unit included in any one of the micro batteries may also serve as the charge / discharge instruction unit.

  According to this power storage device, it is not necessary to separately provide a charge / discharge instruction unit, so that the configuration of the power storage device can be simplified.

  Further, in the above power storage device, the individual charge / discharge control unit included in each of the microbatteries stores a program necessary for operating as the charge / discharge instruction unit, and each of the microbatteries includes It is preferable that the individual charge / discharge control unit determines the individual charge / discharge control unit that also serves as the charge / discharge instruction unit by communicating with each other.

  According to this power storage device, any individual charge / discharge control unit can be a charge / discharge instruction unit, and an individual charge / discharge control unit to be a charge / discharge instruction unit can be automatically determined. Therefore, it is possible to automatically construct a power storage device that controls the charging and discharging of the battery module as described above by simply combining a plurality of micro batteries.

  The microbattery of the present invention is a microbattery that is electrically connected to a common power line and constitutes one power storage device, the battery module charging and discharging DC power, and the battery module discharging An individual power converter that converts DC power to be output and outputs power to the power line, and converts power input from the power line into DC power charged by the battery module, and controls charging and discharging of the battery module An individual charge / discharge control unit, and the individual charge / discharge control unit operates as a charge / discharge instruction unit that instructs charging and discharging of each of the other micro batteries constituting the same power storage device. Is stored in the other microbattery that constitutes the same power storage device. As a result of communication with the separate charge / discharge control unit, the individual charge / discharge control unit that has been operated as the charge / discharge instruction unit is configured to charge the battery module included in each of the micro batteries constituting the power storage device, and Discharging is individually determined and an instruction is given to the individual charge / discharge control unit included in the other microbattery constituting the power storage device.

  According to the power storage device and the microbattery having the above characteristics, a large-sized power conversion unit is not required to cope with the case where all battery modules charge and discharge at the same time and with maximum power as provided in the conventional power storage device. In addition, unnecessary charging and discharging of the battery module can be prevented. Therefore, even if a plurality of battery modules are provided, charging and discharging can be performed efficiently.

The block diagram shown about an example of the structure of the electrical storage apparatus which concerns on 1st Embodiment of this invention. The conceptual diagram of the charging / discharging method which contrasted and showed the charging / discharging method of the battery module in the conventional electrical storage apparatus, and the charging / discharging method of the battery module in the electrical storage apparatus which concerns on 1st Embodiment of this invention. The block diagram shown about an example of a structure of the electrical storage apparatus which concerns on 2nd Embodiment of this invention. The block diagram shown about the modification of the electrical storage apparatus which concerns on 1st Embodiment of this invention. The block diagram shown about the modification of the electrical storage apparatus which concerns on 1st Embodiment of this invention. The graph shown about an example of the conversion characteristic of a general inverter.

<First Embodiment>
An example of the configuration of the power storage device according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an example of the configuration of the power storage device according to the first embodiment of the present invention.

  As shown in FIG. 1, the power storage device 1 </ b> X according to the first embodiment of the present invention includes a plurality of micro batteries 10 </ b> X and one charge / discharge instruction unit 20. Each of the micro batteries 10X is electrically connected to a common AC power line A (power line) to constitute one power storage device 10X. In addition to the microbattery 10X, the AC power line A outputs a load that consumes AC power or a power generator that supplies AC power (for example, DC power obtained by power generation is converted into AC power and output) A solar cell provided with an inverter) may be connected. Further, the AC power line A may be configured to be connected to the commercial power system via a relay, a converter, or the like.

  The micro battery 10 </ b> X includes a battery module 11, a micro inverter 12 (individual power conversion unit), and an individual charge / discharge control unit 13, and has an integrated structure. For example, the micro battery 10X has a structure in which the battery module 11, the micro inverter 12, and the individual charge / discharge control unit 13 are integrated into one package (housing). Each of the micro batteries 10X has a structure having a detachable connector such as a pin connector, and is detachable integrally with the AC power line A.

  The battery module 11 is configured by connecting at least one battery cell (unit cell) that charges and discharges DC power. The micro inverter 12 converts the DC power discharged from the battery module 11 into AC power and outputs the AC power to the AC power line A, and converts AC power input from the AC power line A into DC power charged by the battery module 11. Equipment.

  The micro inverter 12 includes a synchronous control device for monitoring the state of the AC power of the AC power line A and operating in synchronization with the AC power. Therefore, as illustrated in FIG. 1, even if a plurality of micro batteries 10 </ b> X are electrically connected via the AC power line A, the battery module 11 of any micro battery 10 </ b> X does not cause a phase shift of the AC power. Can be charged and discharged.

  The individual charge / discharge control unit 13 includes, for example, an arithmetic device such as a CPU (Central Processing Unit) and a storage device such as a semiconductor memory, and controls operations of the battery module 11 and the micro inverter 12. In particular, the individual charge / discharge control unit 13 controls the charging and discharging of the battery module 11. At this time, the individual charge / discharge control unit 13 receives various information on the state of the battery module 11 acquired from a BMS (Battery Management System) provided along with the battery module 11 (for example, the entire battery module 11 or individual battery cells). It is preferable to control the charging and discharging of the battery module 11 based on the voltage value, current value, temperature, charge rate (SOC: State of charge, etc.). The individual charge / discharge control unit 13 may be a part of the BMS. The individual charge / discharge control unit 13 may be integrated with the micro inverter 12.

  The charge / discharge instruction unit 20 is composed of an arithmetic device such as a CPU and a storage device such as a semiconductor memory, for example. To do. The individual charge / discharge control unit 13 controls the operation of the battery module 11 and the micro inverter 12 based on an instruction from the charge / discharge instruction unit 20. In addition, the charge / discharge instruction | indication part 20 acquires the various information regarding the state of the battery module 11 from the separate charge / discharge control part 13, if needed, and charge and discharge with respect to the separate charge / discharge control part 13 based on the said information Instruct.

  The charge / discharge instruction unit 20 is an instruction given from a device that adjusts the supply and demand of power, such as a power conditioner (an instruction to charge and store surplus power in the power storage device 1X, an instruction to compensate for insufficient power by discharging the power storage device 1X) In response, the individual charge / discharge control unit 13 is instructed to charge and discharge so that the instruction is achieved. The charge / discharge instruction unit 20 may be a part of a power conditioner. The charge / discharge instruction unit 20 monitors the AC power state of the AC power line A, the generator state, the load state, etc., and performs independent control so that the supply and demand of power is adjusted. May be.

  At this time, the charge / discharge instruction unit 20 individually determines charging and discharging of the battery modules 11 included in each of the micro batteries 10X, and instructs the individual charge / discharge control unit 13 included in each of the micro batteries 10X. Further, the charge / discharge instruction unit 20 is configured to individually charge or discharge the battery modules 11 that are charged or discharged simultaneously (in other words, the number of battery modules 11 that are not charged and discharged simultaneously is increased). An instruction is given to the discharge controller 13.

  Here, the effect obtained when the charge / discharge instruction unit 20 instructs the individual charge / discharge control unit 13 as described above will be described with reference to the drawings. FIG. 2 is a conceptual diagram of a charge / discharge method showing a comparison between a charge / discharge method for a battery module in a conventional power storage device and a charge / discharge method for a battery module in the power storage device according to the first embodiment of the present invention. .

  FIG. 2A is a schematic diagram showing a method for charging and discharging a battery module in a conventional power storage device as proposed in Patent Document 1 described above. Moreover, FIG.2 (b) is the schematic diagram which showed the charging / discharging method of the battery module 11 in the electrical storage apparatus 1X which concerns on 1st Embodiment of this invention.

  The hatched area shown in the battery module block in FIGS. 2A and 2B represents the magnitude of DC power that is charged and discharged by the battery module, and the battery module may be charged and discharged. The percentage (%) when the maximum power that can be made is 100% is also shown. Similarly, hatched areas shown in the inverter and microinverter blocks in FIGS. 2A and 2B represent the magnitude of power converted by the inverter and microinverter, and the maximum converted power is 100. The percentage (%) is also shown. Further, each of FIGS. 2A and 2B charges and discharges power corresponding to 20% of the entire battery module when the power storage device includes five battery modules having equal performance. This is an example of the case.

  As shown in FIG. 2A, in the conventional power storage device, one inverter is provided for a plurality (five) of battery modules. Therefore, a large inverter is required to cope with the case where a plurality of battery modules are charged and discharged with the maximum power. Therefore, in FIG. 2A, when all the battery modules are charged and discharged with the maximum power (100%), the maximum conversion power (100%) of the inverter is assumed.

  At this time, as shown in FIG. 2A, if charging and discharging are performed with electric power corresponding to 20% of the entire battery module, electric power converted by the inverter is as low as about 20%.

  Therefore, in the conventional power storage device, when the electric power charged and discharged in the whole battery module is small, the electric power converted by the inverter is also small, so that the conversion efficiency in the inverter is deteriorated (see FIG. 6). Note that even if the rate at which each battery module is charged and discharged can be arbitrarily set (for example, the power charged and discharged by one battery module is set to 100% and the rest is turned off). This is an unavoidable problem in the conventional power storage device that occurs (if possible).

  On the other hand, as shown in FIG. 2B, in the power storage device 1 </ b> X according to the first embodiment of the present invention, one microinverter 12 is provided for one battery module 11. Therefore, the microinverter 12 that needs to be able to cope with the case where one battery module 11 is charged and discharged with the maximum power does not need to be configured with a large inverter. Therefore, in FIG. 2B, when one battery module 11 is charged and discharged with the maximum power (100%), the maximum conversion power (100%) of the micro inverter 12 is assumed.

  In the power storage device 1X according to the first embodiment of the present invention, the charge / discharge instruction unit 20 instructs the individual charge / discharge control unit 13 to reduce the number of battery modules 11 that are charged or discharged simultaneously. Therefore, as in the example shown in FIG. 2B, when charging and discharging is performed with the power corresponding to 20% of the total in the five battery modules 11, one battery module 11 is charged with 100% power. As a result, the remaining four battery modules 11 are turned off. At this time, similarly to the battery module 11, the micro inverters 12 provided one-to-one with respect to the battery module 11 operate at 100%, and the remaining four are turned off.

  Therefore, in the power storage device 1X according to the first embodiment of the present invention, even if the electric power charged and discharged in the entire battery module is small, the electric power converted by the micro inverter 12 is large. The conversion efficiency can be increased (see FIG. 6).

  As described above, in the power storage device 1X according to the first embodiment of the present invention, since each of the micro batteries 10X includes the micro inverter 12, all the battery modules that the conventional power storage device includes are all at once. A large-sized inverter for coping with charging and discharging with electric power can be eliminated. Further, since the charge / discharge instruction unit 20 individually determines charging and discharging of the battery modules 11 included in each of the micro batteries 10X, the appropriate battery modules 11 are charged and discharged as necessary, and unnecessary batteries are discharged. Charging and discharging of the module 11 can be prevented. Therefore, even if it has the some battery module 11, it becomes possible to charge and discharge efficiently.

  Furthermore, in the power storage device 1X according to the first embodiment of the present invention, when it is necessary to charge or discharge a specific amount of power in the entire battery module 11, the few battery modules 11 are charged or discharged. Therefore, the direct current power that inevitably charges or discharges one battery module 11 increases. Thereby, in the microbattery 10X including the battery module 11 that performs charging or discharging, the electric power converted by the microinverter 12 is increased, so that the conversion efficiency in the microinverter 12 can be constantly increased.

  Even if the number of battery modules 11 that are charged or discharged simultaneously is reduced, if the combination of the battery module 11 and the micro inverter 12 constituting one micro battery 10X is inappropriate, the conversion efficiency in the micro inverter 12 is improved. There is concern that it will not be improved sufficiently. Specifically, for example, the maximum power that can be charged and discharged by the battery module 11 does not reach the rated conversion efficiency in the micro inverter 12.

  Therefore, each of the micro batteries 10X includes a battery module 11 having the ability to charge and discharge the minimum DC power for achieving the rated conversion efficiency in the micro inverter 12, or the conversion efficiency in the micro inverter 12 It is preferable to provide the battery module 11 having the ability to charge and discharge the minimum DC power to maximize the power.

  In addition, as described above, if the number of battery modules 11 that are charged or discharged simultaneously is reduced, there is a concern that some micro batteries 10X may be overused, resulting in an adverse effect of uneven deterioration of the battery modules 11. Is done. Specifically, there is a concern that the apparent discharge capacity of the power storage device 1X (the overall discharge capacity of the battery module 11) is rapidly reduced.

  Therefore, it is preferable that the charge / discharge instruction unit 20 instructs the individual charge / discharge control unit 13 to preferentially charge and discharge the battery module 11 that is not deteriorated. Thereby, since deterioration of the battery module 11 can be leveled, it is possible to delay the decrease in the apparent discharge capacity of the power storage device 1X.

  In this case, for example, the charge / discharge instruction unit 20 records a history of instructions to the individual charge / discharge control unit 13, and the degree of deterioration of the battery modules 11 (for example, each battery module 11 is charged and discharged in the past). Power amount or current amount, number of times of charging, number of times of discharging, etc.) may be recognized.

  Further, the control policy of preferentially charging and discharging a battery module 11 that is not deteriorated and the control policy of reducing the number of battery modules 11 that perform charging or discharging are basically compatible. However, in the special case where the control policies of both compete (for example, when the variation in the charge / discharge performance of the battery module 11 is extremely large, in order to minimize the number of battery modules 11 to be charged or discharged, the most Assuming that the deteriorated battery module 11 needs to be charged or discharged), it may be determined in advance which control policy is to be prioritized. Further, a control policy other than this (for example, a control policy that preferentially charges a battery module provided in a microbattery that can be used in other power consuming devices, as described in [2] of <deformation etc.> described later). ), And the priority of control policies to be prioritized may be determined in advance.

Second Embodiment
Next, a power storage device according to a second embodiment of the present invention will be described. The power storage device according to the second embodiment of the present invention is mostly in common with the power storage device 1X (see FIGS. 1 and 2) described in the first embodiment. Therefore, in the following, the description related to the first embodiment described above is omitted as appropriate for the power storage device according to the second embodiment of the present invention as long as there is no contradiction, and details of parts different from the first embodiment described above are omitted. Explained.

  First, an example of the configuration of a power storage device according to the second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a block diagram showing an example of the configuration of the power storage device according to the second embodiment of the present invention.

  As illustrated in FIG. 3, the power storage device 1Y according to the second embodiment of the present invention includes a plurality of micro batteries 10Ya and 10Yb. The micro batteries 10Ya and 10Yb include a battery module 11, a micro inverter 12, and individual charge / discharge control units 13Ya and 13Yb.

  Unlike the power storage device 1X (see FIG. 1) according to the first embodiment of the present invention, the power storage device 1Y according to the second embodiment of the present invention does not include the charge / discharge instruction unit 20. However, in the power storage device 1Y according to the second embodiment of the present invention, the individual charge / discharge control unit 13Ya included in any one of the micro batteries 10Ya also serves as the charge / discharge instruction unit, and in this respect, the first embodiment of the present invention. It differs from the power storage device 1X according to the embodiment. However, also in the power storage device 1Y according to the second embodiment of the present invention, the charge / discharge instruction unit 20 included in the power storage device 1X according to the first embodiment of the present invention is provided by the individual charge / discharge control unit 13Ya that also serves as the charge / discharge instruction unit. Since the same control is performed, the same effect as the power storage device 1X according to the first embodiment of the present invention can be obtained.

  And in the electrical storage apparatus 1Y which concerns on 2nd Embodiment of this invention, since it becomes unnecessary to provide the charging / discharging instruction | indication part 20 (refer FIG. 1) separately, it is possible to simplify the structure of the electrical storage apparatus 1Y.

  Here, details of the microbattery 10Ya including the individual charge / discharge control unit 13Ya also serving as the charge / discharge instruction unit and the microbattery 10Yb including the individual charge / discharge control unit 13Yb also serving as the charge / discharge instruction unit will be described. In the following description, the individual charge / discharge control unit 13Ya that also serves as the charge / discharge instruction unit is referred to as the “individual charge / discharge control unit 13Ya of the parent device”, and the individual charge / discharge control unit 13Yb that also does not serve as the charge / discharge instruction unit. These are distinguished from each other by referring to “individual charging / discharging control unit 13Yb of the slave unit”. Similarly, the micro battery 10Ya including the individual charging / discharging control unit 13Ya of the parent device is referred to as “the micro battery 10Ya of the parent device”, and the micro battery 10Yb including the individual charging / discharging control unit 13Yb of the child device is referred to as “the micro battery of the child device”. 10Yb "to distinguish them.

  The micro battery 10Ya of the parent device and the micro battery 10Yb of the child device may be configured with dedicated and different kinds of micro batteries. However, if the master microbattery 10Ya and the slave microbattery 10Yb are composed of general-purpose and the same type of microbatteries, it is not necessary to manufacture a plurality of types of microbatteries, so that the cost of the microbattery can be reduced. In addition, a used microbattery can be freely incorporated into the power storage device and reused without restriction of the parent device and the child device.

  Furthermore, in this case, if each of the individual charging / discharging control unit 13Ya of the parent device and the individual charging / discharging control unit 13Yb of the child device stores in advance a program necessary to operate as the charging / discharging instruction unit, the power storage device 1Y This is preferable because it is not necessary to separately input the program to the individual charging / discharging control unit 13Ya of the parent device after the construction of the device, and the work necessary for setting the parent device and the child device can be simplified.

  However, when the micro battery 10Ya of the master unit and the micro battery 10Yb of the slave unit are configured with general-purpose and the same type of micro battery as described above, which micro battery is the master unit and which micro battery is the slave unit. It will be necessary to decide.

  For example, a switch for selecting a parent device and a child device may be provided on a general-purpose micro battery, and the user may determine the parent device and the child device of the micro battery by manually switching the switch. In this case, the individual charging / discharging control unit 13Ya of the parent device and the individual charging / discharging control unit 13Yb of the child device are wired or wireless (especially in the vicinity of allowing communication only within the size range of a general power storage device casing) You may recognize micro battery 10Yb of the subunit | mobile_unit which is the object which instruct | indicates charge and discharge by performing communication by distance wireless communication. Further, the user or manufacturer of the power storage device 1Y uses, for example, the serial number of the micro battery 10Yb of the slave unit (a code for identifying individual micro batteries used for communication with other micro batteries) as the master unit. By directly inputting to the micro battery 10Ya, the individual charge / discharge control unit 13Ya of the parent device may recognize the micro battery 10Yb of the child device that is a target for instructing charging and discharging.

  In addition, for example, the individual charge / discharge control units communicate with each other by wire or wireless (particularly, short-range wireless communication that allows communication only within the range of the size of a general power storage device housing). You may determine automatically the separate charging / discharging control part 13Ya of a machine. In this case, the power storage device 1Y can be automatically constructed only by combining a plurality of micro batteries.

  Further, in this case, each of the individual charge / discharge control units determines the parent device and the child device based on a rule that can narrow down the parent device to one. For example, the rule may be a rule determined independently of the characteristics of the micro battery, such as the smallest serial number of the micro battery or the smallest serial number generated at random during communication. Further, for example, as the rule, based on the characteristics of the micro battery, such as the estimated life of the micro battery (particularly, the battery module 11) is the longest, the manufacturing date of the micro battery is the newest, and the discharge capacity of the battery module 11 is the largest. The rules to be decided are listed.

  However, when adopting a rule determined based on the characteristics of the microbattery, each of the individual charge / discharge control units must be able to acquire data including information on the characteristics of the microbattery. In this regard, for example, if the configuration described in [1] of <deformation and the like> described later and FIG. 5 is employed, each of the individual charge / discharge control units can acquire the data (device data).

<Deformation, etc.>
[1] In the power storage devices 1X and 1Y according to the first and second embodiments of the present invention described above, each of the micro batteries 10X, 10Ya, and 10Yb records data for reference by the charge / discharge instruction unit. You may comprise so that a data recording part may be provided. An example of the structure of the power storage device in this case will be described with reference to the drawings. FIG. 4 is a block diagram showing a modification of the power storage device according to the first embodiment of the present invention, and FIG. 5 is a block diagram showing a modification of the power storage device according to the second embodiment of the present invention.

  A power storage device 1X ′ that is a modification of the power storage device according to the first embodiment of the present invention shown in FIG. 4 and a power storage device 1Y ′ that is a modification of the power storage device according to the second embodiment of the present invention shown in FIG. The only difference in configuration is whether the charge / discharge instruction unit 20 ′ is provided separately (see FIG. 4) or whether the individual charge / discharge control unit 13Ya ′ of the master unit also serves as the charge / discharge instruction unit (see FIG. 5). The operations of the charge / discharge instruction unit 20 ′ and the individual charge / discharge control unit 13Ya ′ of the parent device are the same. Therefore, here, only the power storage device 1X ′, which is a modification of the power storage device according to the first embodiment of the present invention shown in FIG. 4, will be described, and the description will be given for the power storage according to the second embodiment of the present invention shown in FIG. 5. The description of the power storage device 1Y ′ is omitted as appropriate for the power storage device 1Y ′ that is a modification of the device.

  In the power storage device 1 </ b> X ′ illustrated in FIG. 4, the data recording unit 14 included in each of the micro batteries 10 </ b> X ′ records device data including information regarding devices that configure the micro battery 10 </ b> X ′ including the data recording unit 14. . For example, the usage history of the battery module 11 (for example, the amount and number of times of charging and discharging in the past), the temperature history of the usage environment, specifications (for example, manufacturer, model, battery cell type / number / connection method, various ratings) Value), discharge capacity measured at a specific point in time (for example, when recovered as second-hand goods, point of reuse, etc.), basic characteristics (for example, a manufacturer's charge test) Information such as the correlation between the number of cycles and the deterioration of the discharge capacity, the correlation between the temperature of the use environment and the deterioration of the discharge capacity, etc. can be included in the device data. In addition, it is not restricted to the battery module 11, The information regarding the micro inverter 12 can also be contained in apparatus data.

  The charge / discharge instruction unit 20 ′ acquires device data from each of the data recording units 14, and recognizes the deterioration state of the battery module 11 by performing a calculation for estimating the deterioration state of the battery module 11 as necessary. To do. For example, the charge / discharge instruction unit 20 ′ collates the use history and temperature history with basic characteristics (correlation between the use history and temperature history and deterioration of the discharge capacity), or refers to the actually measured discharge capacity at a specific time. By doing so, the deterioration state of the battery module 11 is recognized. Note that the charge / discharge instruction unit 20 ′ may recognize the entire deterioration state of the microbattery 10 </ b> X ′ by taking into account the deterioration state of the micro inverter 12 without being limited to the battery module 11.

  As a result, the charge / discharge instruction unit 20 ′ is necessary for performing control that preferentially charges and discharges the battery module 11 that is not deteriorated as described in the first embodiment. Alternatively, it is possible to recognize the respective deterioration states of the entire microbattery 10X ′. In particular, in this modification, there is a past deterioration of the battery module that the charge / discharge instruction unit 20 ′ is not aware of, such as a deterioration state of a battery module included in a used microbattery used in another power storage device in the past. In addition, it becomes possible for the charge / discharge instruction unit 20 'to recognize.

  In addition, the data recording unit 14 also records various information related to the state of the battery module 11 (for example, information acquired from the BMS by the individual charge / discharge control unit 13 ′) via the individual charge / discharge control unit 13 ′. The data recording unit 14 may acquire the various information from the charge / discharge instruction unit 20 ′ instead of the individual charge / discharge control unit 13 ′, or may acquire the various information from the battery module 11 or the BMS. .

  As described above, when the data recording unit 14 acquires and records various types of information related to the state of the battery module 11, the device data can always be in the latest state. Therefore, when the microbattery 10X ′ is removed from the power storage device 1X ′ on the assumption that it is reused by another power storage device, some editing is performed on the device data recorded by the data recording unit 14 included in the microbattery 10X ′. (For example, adding information such as a use history separately recorded by the charge / discharge instruction unit 20 ′ to the device data to update the device data to the latest state) can be made unnecessary. . Therefore, it becomes possible to easily reuse the microbattery 10X ′.

[2] The power storage devices 1X and 1Y according to the first and second embodiments of the present invention are other power consuming devices other than the AC power line A and the power storage devices 1X and 1Y (for example, electric motorcycles, power tools, portable power supplies, etc. ), And may be provided with micro batteries 10X, 10Ya, 10Yb for supplying power to the power consuming device when attached to the power consuming device. However, in the case of the power storage device 1Y according to the second embodiment of the present invention, it is preferable that the micro battery that can be used in other power consuming devices is set to be the micro battery 10Yb of the slave unit.

  In this case, the battery module 11 included in the microbatteries 10X and 10Yb that can be used in other power consuming devices removed from the AC power line A is sufficiently charged, and the other battery modules 11X and 10Yb to which the microbatteries 10X and 10Yb are attached. It is preferable to make the power consuming device sufficiently usable because the convenience of the other power consuming device can be improved.

  Therefore, when the micro batteries 10X and 10Yb that can be used in other power consuming devices are connected to the AC power line A to form the power storage devices 1X and 1Y, the charge / discharge instruction unit 20 or the individual charge / discharge control unit of the master unit 13Ya may instruct the individual charge / discharge control units 13, 13Ya, 13Yb so that the battery modules 11 included in the micro batteries 10X, 10Yb are preferentially charged.

  Note that the microbatteries 10X and 10Yb may be configured so that the battery module 11 detachable from the microbatteries 10X and 10Yb can be used in other power consuming devices. Also in this case, the charging / discharging instruction unit 20 or the individual charging / discharging control unit 13Ya of the master unit is configured so that the battery module 11 that can be used in other power consuming devices is preferentially charged. What is necessary is just to instruct 13Ya and 13Yb.

  In addition, the control policy of preferentially charging the battery modules 11 included in the micro batteries 10X and 10Yb that can be used in other power consuming devices and the control policy of reducing the number of battery modules 11 that perform charging or discharging are as follows: Basically it is compatible. However, in a special case where the control policies of both compete (for example, when the variation in the charge / discharge performance of the battery module 11 is extremely large, in order to minimize the number of battery modules 11 to be charged, other power Assuming that it is necessary to charge the battery module 11 included in another microbattery instead of the microbatteries 10X and 10Yb that can also be used in consumer devices, it is determined in advance which control policy is to be prioritized. You may keep it. Furthermore, other control policies (for example, a control policy for preferentially charging and discharging a battery module 11 that has not deteriorated as described at the end of <first embodiment>) should be given priority. The order of control policies may be determined in advance.

[3] Contrary to the modification of the power storage device of [2] above, the battery module provided in the microbatteries 10X and 10Yb that can be used in other power supply devices (for example, power generation devices such as solar cells and engine generators). 11 may be preferentially discharged. Although it is necessary to appropriately read “charge” in the description of [2] above as “discharge”, the description of [2] is also applicable to a modified example of this power storage device.

  Further, the modified examples [2] and [3] are not rejected and can be implemented simultaneously. Specifically, one power storage device includes a microbattery that can be used in other power consuming devices and a microbattery that can also be used in other power supply devices, and a microbattery that can also be used in other power consuming devices. The battery module provided may be preferentially charged, and the battery module provided in a microbattery that can be used in other power supply devices may be preferentially discharged.

[4] In the power storage devices 1X and 1Y according to the first and second embodiments of the present invention, when the AC power line A is configured to be interconnected to the commercial power system, the commercial power system and the power storage device 1X. , 1Y are connected to each other, but there is a possibility that a state where the commercial power system is interrupted due to a trouble or the like (hereinafter referred to as “independent operation state”) may occur. And when an independent operation state arises, since the restoration | reconstruction construction | work of a commercial power system is prevented because alternating current power flows in into a commercial power system from AC power line A, it will become a problem.

  Therefore, the power storage devices 1X and 1Y have a single operation state detection device that detects the single operation state. If it is detected that the single operation state is detected, the AC power line A and the commercial power system are disconnected, It is preferable to stop the micro batteries 10X and 10Yb.

  For example, the micro inverter 12 included in each of the micro batteries 10X, 10Ya, and 10Yb outputs an active signal and is in a single operation state by analyzing the state of the AC power in the AC power line A into which the active signal is injected. A single operation state detection device for detecting In this case, when it is detected that the single operation state detection device provided in a certain micro inverter 12 is in the single operation state, the information is charged via the individual charge / discharge control units 13, 13 Ya, and 13 Yb that control the micro inverter 12. This is transmitted to the discharge instruction unit 20 or the individual charge / discharge control unit 13Ya of the master unit. Then, the charging / discharging instruction unit 20 or the individual charging / discharging control unit 13Ya of the master unit instructs the disconnection of the relay connecting the AC power line A and the commercial power system, the instruction to stop the converter, all the micro batteries 10X, An instruction to stop 10Ya and 10Yb is given.

  However, in this case, if the microinverters 12 included in each of the plurality of microbatteries 10X, 10Ya, and 10Yb output active signals all at once, the active signals interfere to reduce the detection accuracy of the isolated operation state, Problems such as an active signal adversely affecting the power supplied from the grid may occur.

  Accordingly, it is preferable that in the power storage devices 1X and 1Y, only the micro inverter 12 included in any one of the micro batteries 10X, 10Ya, and 10Yb is configured to output an active signal.

  For example, in the power storage device 1Y according to the second embodiment, only the microinverter 12 included in the parent microbattery 10Ya outputs an active signal, and the microinverter 12 included in the child microbattery 10Yb does not output an active signal. It may be. Furthermore, at this time, the individual charging / discharging control unit 13Ya of the parent device may give an instruction to prohibit the output of the active signal from the micro battery 12 to the individual charging / discharging control unit 13Yb of the child device.

  Further, for example, in the power storage device 1X according to the first embodiment, the micro battery 10X (hereinafter, “representative micro battery”) determined by the same method as the parent micro battery 10Ya in the power storage device 1Y according to the second embodiment. Only the microinverter 12 included in the microbattery 10X may output an active signal, and the microinverter 12 included in the other microbattery 10X may not output the active signal. Further, at this time, the charge / discharge instruction unit 20 gives an instruction to prompt the output of an active signal by the micro inverter 12 to the individual charge / discharge control unit 13X included in the representative micro battery 10X, and to the other micro batteries 10X. Thus, an instruction to prohibit the output of the active signal by the microinverter 12 may be given.

[5] In the power storage devices 1X and 1Y according to the first and second embodiments of the present invention, when the AC power line A is not connected to the commercial power system (when the power storage devices 1X and 1Y are operating independently) ), AC power serving as a reference with a stable voltage and frequency is not supplied to the AC power line A. Therefore, depending on the type and specification of the inverter circuit in the micro inverter 12 included in each of the micro batteries 10X, 10Ya, and 10Yb, there may be a problem that the AC power in the AC power line A becomes unstable.

  This problem will be specifically described. First, a general inverter includes a voltage control type that outputs AC power having a constant voltage and frequency, and a current control type that outputs a predetermined current so as to follow the voltage and frequency of the output AC power. There are types. Here, the voltage control type inverter becomes unstable due to interference with the AC power of the output destination. On the other hand, the current control type inverter cannot be used unless the power and frequency of the AC power of the output destination to be followed are stable. Therefore, when the power storage devices 1X and 1Y operate independently, the AC power in the AC power line A can become unstable regardless of whether the micro inverter 12 is a current control type or a voltage control type.

  As one method for solving this problem, the power storage devices 1X and 1Y each include a voltage-controlled micro-inverter (particularly one having a relatively large inverter capacity) for outputting reference AC power. It is conceivable to configure each of the microbattery and at least one microbattery provided with a current-controlled microinverter for following the reference AC power. However, in this case, the power storage devices 1X and 1Y need to include two types of microbatteries, and when the power storage devices 1X and 1Y operate, it is necessary to operate a microbattery including a voltage-controlled micro inverter. Therefore, the configuration and operation of the power storage devices 1X and 1Y can be restricted.

  Therefore, it is preferable that the power storage devices 1X and 1Y be configured so that each of the micro batteries 10X, 10Ya, and 10Yb includes the micro inverter 12 having both voltage control type and current control type characteristics. Note that the microinverter 12 having both voltage control type and current control type characteristics includes, for example, a microinverter configured to be switchable between the voltage control type and the current control type, A microinverter that performs operations having both characteristics of the current control type (specifically, for example, output based on a reference value related to voltage, frequency, and power and a measured value of an output destination as proposed in WO2013 / 008413) Inverter that determines the current to be).

[6] In the power storage devices 1X and 1Y according to the first and second embodiments of the present invention, in FIGS. 1 and 3, each of the micro batteries 10X, 10Ya, and 10Yb includes the micro inverter 12, and the common AC power line A However, each of the micro batteries 10X, 10Ya, and 10Yb may include a micro converter (individual power conversion unit) and be connected to a common DC power line (power line). In addition to the micro batteries 10X, 10Ya, and 10Yb, a load that consumes DC power and a power generation device that supplies DC power (for example, a solar cell) may be connected to the DC power line. Further, the DC power line may be configured to be connected to the commercial power system through a relay, an inverter, or the like.

  Further, the micro batteries 10X, 10Ya, and 10Yb may include both the micro inverter 12 and the micro converter, and may be configured to selectively input / output AC power and DC power.

  INDUSTRIAL APPLICABILITY The present invention can be used for a power storage device including a plurality of micro batteries each having a battery module that charges and discharges DC power, and a micro battery constituting the power storage device.

1X, 1Y, 1X ′, 1Y ′: Power storage devices 10X, 10Ya, 10Yb, 10X ′, 10Ya ′, 10Yb ′: Micro battery 11: Battery module 12: Micro inverter (individual power conversion unit)
13, 13Ya, 13Yb, 13 ', 13Ya', 13Yb ': Individual charge / discharge control unit (13Ya, 13Ya': Individual charge / discharge control unit also serving as a charge / discharge instruction unit)
14: Data recording unit 20, 20 ': Charge / discharge instruction unit A: AC power line (power line)

Claims (12)

A power storage device comprising a plurality of micro batteries that are electrically connected to a common power line,
A charge / discharge instruction unit that instructs charging and discharging for each of the micro batteries,
Each of the microbatteries
A battery module for charging and discharging DC power; and
An individual power converter that converts DC power discharged by the battery module and outputs power to the power line, and converts power input from the power line to DC power charged by the battery module;
In accordance with an instruction from the charge / discharge instruction unit, an individual charge / discharge control unit that controls charging and discharging of the battery module, and
The charge / discharge instruction unit individually determines charging and discharging of the battery module included in each of the micro batteries, and instructs the individual charge / discharge control unit included in each of the micro batteries. Power storage device.   2. The power storage device according to claim 1, wherein the charge / discharge instruction unit instructs the individual charge / discharge control unit to reduce the number of the battery modules that are charged or discharged simultaneously.   Each of the said microbatteries is equipped with the said battery module which has the capability to charge and discharge the minimum direct-current power for achieving the rated conversion efficiency in the said separate electric power conversion part, The said battery module is characterized by the above-mentioned. The power storage device described in 1.   Each of the said microbatteries is provided with the said battery module which has the capability to charge and discharge the minimum direct current | flow electric power for maximizing the conversion efficiency in the said separate electric power converter. The power storage device described in 1.   The charge / discharge instruction unit instructs the individual charge / discharge control unit to preferentially charge and discharge the battery module that is not deteriorated. The power storage device described. Each of the microbatteries further comprises a data recording unit that records device data including information indicating a deterioration state of the battery module,
The charge / discharge instruction unit recognizes a deterioration state of the battery module included in each of the micro batteries by acquiring the device data from the data recording unit included in each of the micro batteries. Item 6. The power storage device according to Item 5.   At least one of the micro batteries has the battery module, the individual power conversion unit, and the individual charge / discharge control unit integrated with each other, and is detachable integrally with the power line. The power storage device according to any one of claims 1 to 6. The microbattery that is detachable with respect to the power consuming device other than the power line and the power storage device and that supplies power to the power consuming device when attached to the power consuming device is connected to the power line. And constituting the power storage device,
The power storage device according to claim 7, wherein the charge / discharge instruction unit instructs the individual charge / discharge control unit to preferentially charge the battery module included in the microbattery. The power line is configured to be interconnected to a commercial power system,
Each of the individual power conversion units outputs an active signal for detecting an isolated operation state in which the power line and the commercial power system are interconnected but the commercial power system is in a power failure state It has an operating state detection device,
The charge / discharge instruction unit instructs the individual charge / discharge control unit included in any one of the micro batteries to output only the active signal from the individual power conversion unit included in the micro battery. The power storage device according to any one of claims 1 to 8.   The power storage device according to any one of claims 1 to 9, wherein the individual charge / discharge control unit included in any one of the micro batteries also serves as the charge / discharge instruction unit. The individual charge / discharge control unit included in each of the micro batteries stores a program necessary for operating as the charge / discharge instruction unit,
The said individual charging / discharging control part with which each of the said microbattery determines the said individual charging / discharging control part which serves as the said charging / discharging instruction | indication part by communicating with each other. Power storage device. A microbattery that is electrically connected to a common power line to form one power storage device,
A battery module for charging and discharging DC power; and
An individual power converter that converts DC power discharged by the battery module and outputs power to the power line, and converts power input from the power line to DC power charged by the battery module;
An individual charge / discharge control unit for controlling charging and discharging of the battery module,
The individual charge / discharge control unit stores a program necessary to operate as a charge / discharge instruction unit that instructs charging and discharging to each of the other micro batteries constituting the same power storage device,
As a result of communication with the individual charge / discharge control unit included in another microbattery that constitutes the same power storage device, the individual charge / discharge control unit that has been operated as the charge / discharge instruction unit The charging and discharging of the battery module included in each of the microbatteries to be configured is individually determined, and the individual charge / discharge control unit included in the other microbattery configuring the power storage device is instructed. Micro battery to be used.

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