JP2016019350A - Power storage system - Google Patents

Abstract

In a power storage system for charging a plurality of storage batteries, a circuit configuration is simplified.
The power storage system 100 receives power from an external power source PS, outputs DC power via a converter 10, and has a charging device 1 having a communication function and a plurality of connectable storage batteries 3, 5 , Any one set of storage batteries and the management device 4 or 6 thereof and the connection device 2 for connecting the power line and the communication line to each other between the charging device 1.
[Selection] Figure 7

Description

  The present invention relates to a power storage system that stores power of a commercial system power supply or privately generated power in a secondary battery.

The power of the commercial system power supply and the power of solar power generation can be stored in a storage battery that is a secondary battery. Thereby, not only a storage battery can be used as an emergency power supply but also a storage battery can be actively used as a countermeasure for peak shift, for example.
Typical storage batteries include stationary storage batteries and in-vehicle batteries such as electric vehicles (EV) and plug-in hybrid electric vehicles (PHEV).

JP 2014-3863 A

In the conventional power storage system as described above, in order to connect a plurality of types of storage batteries to a charging device, each storage battery may be provided with a DC / DC converter, and further an insulated DC / DC converter may be provided (for example, patents). Reference 1 FIG. 1).
However, when the number of converters such as DC / DC converters increases in this way, the circuit configuration of the entire power storage system becomes complicated and the product cost increases. Moreover, since the converter has a conversion loss, the power loss of the entire device increases according to the number of converters.

  In view of such conventional problems, an object of the present invention is to simplify a circuit configuration in a power storage system that charges a plurality of storage batteries.

  The power storage system of the present invention receives power from an external power source, outputs DC power via a converter, and has a communication device, a charging device having a communication function, and any one of a plurality of connectable storage batteries and its storage battery And a connection device for connecting a power line and a communication line to each other between the management device and the charging device.

  ADVANTAGE OF THE INVENTION According to this invention, the converter for every storage battery can be abbreviate | omitted, and it can be set as the electrical storage system of the circuit structure which was simple and reduced the power loss.

It is a single line connection diagram of the electrical storage system concerning a 1st embodiment. It is a single line connection diagram of the electrical storage system concerning a 2nd embodiment. It is a single line connection diagram of the electrical storage system concerning a 3rd embodiment. It is a single line connection diagram of the electrical storage system concerning a 4th embodiment. It is a single line connection diagram of the electrical storage system concerning a 5th embodiment. It is a single line connection diagram of the electrical storage system concerning a 6th embodiment. FIG. 2 is a single line connection diagram of a power storage system in which the charging device in FIG. 1 is more generalized.

[Summary of Embodiment]
The gist of the embodiment of the present invention includes at least the following.

  (1) This power storage system receives power from an external power source, outputs DC power via a converter, and has a communication device, a charging device having a communication function, and any one of a plurality of connectable storage batteries, A connection device for connecting a power line and a communication line is provided between the management device and the charging device.

  In the power storage system configured as in (1) above, a plurality of storage batteries are not simultaneously connected to the charging device. That is, a converter corresponding to a storage battery for handling each storage battery individually as in the case where a plurality of storage batteries are connected in parallel is not required, and the charging device and the storage battery can be simply connected only through the connection device. it can. Therefore, a converter for each storage battery can be omitted, and a power storage system having a simple and inexpensive circuit configuration can be obtained. Moreover, the omission of the converter for each storage battery reduces the conversion loss correspondingly and contributes to the reduction of power loss as a whole. Note that, by connecting the communication line, the charging device can grasp information on the connected storage battery and appropriately control the converter. Further, for example, overcharge and overdischarge of the storage battery can be prevented based on the information.

(2) Moreover, the storage battery in the electrical storage system of (1) may include a stationary storage battery and a storage battery of an electric propulsion vehicle.
This configuration is suitable when a stationary storage battery charging system is added to the charging system of the electric propulsion vehicle, and the storage capacity can be easily increased.

(3) Moreover, in the electrical storage system of (1) or (2), a charging device can also include a solar power generation device.
In this case, the output of solar power generation can be stored during the daytime even when the commercial power supply is interrupted. Further, even when a part of the storage battery is an electric propulsion vehicle and is disconnected from the power storage system, it can be stored in the remaining storage battery (for example, a stationary storage battery).

(4) Further, the power storage system of (2) may include an electric circuit that feeds power from the commercial power supply to the AC input charger mounted on the electric propulsion vehicle via the connection device.
In this case, the charging of the electric propulsion vehicle can be performed simultaneously with the charging of the stationary storage battery.

(5) Moreover, in the electrical storage system in any one of (1)-(4), the said connection apparatus can also be provided in the inside of the said charging device.
In this case, it is easy to configure so that the charging device detects the one of the connected storage batteries with the smaller remaining amount and automatically switches the connection.

(6) In the power storage system according to any one of (1) to (5), the connection device is a single charging cable provided with a connector that can be commonly used for connection with the plurality of storage batteries. May be.
In this case, the function of the connecting device can be realized easily and reliably.

(7) The power storage system of (2) may include an electric circuit that supplies control power to the charging device from a management device that is provided along with the stationary storage battery.
In this case, for example, even when a power failure occurs in a commercial system power supply, even if other external power supplies cannot be used, a control power supply is provided from the management device to the charging device, and for example, the storage battery of the electric propulsion vehicle is charged by the connecting device. If power can be supplied to the battery, the storage battery can be used as an emergency power source.

[Details of the embodiment]
Hereinafter, it will be described in detail with reference to the drawings.

<< First Embodiment >>
FIG. 1 is a single-line connection diagram of the power storage system according to the first embodiment. In the figure, the power storage system 100 includes a charging device 1 and a connection device 2. Two types (or two of the same type) of storage batteries 3 and 5 are additionally provided with BMS (Battery Management System) 4 and 6 as management devices, respectively. Of the straight lines representing connections, the thick lines represent power lines (main circuit wires), the middle lines represent communication lines, and the dotted lines represent control lines. In addition, although the example where two storage batteries 3 and 5 exist is shown here, it can also be set to 3 or more (the same applies to other embodiments below). As the storage batteries 3 and 5, various secondary batteries, such as a lead storage battery, a lithium ion battery, and a molten salt battery, can be used, for example.

  The charging device 1 receives power from an AC commercial power supply 7 that is an external power supply. The charging device 1 has an AC / DC converter 11 that converts alternating current into direct current, a DC / DC converter 12 that converts a direct current voltage, which is an output thereof, into a direct current voltage suitable for charging the storage batteries 3 and 5, and a communication function. And a communication unit 13. The communication unit 13 can acquire the information of the storage battery 3 or 5 from the BMS 4 or 6 and give it to the DC / DC converter 12. The storage batteries 3 and 5 and the BMSs 4 and 6 may also be considered as components of the power storage system 100.

The AC / DC converter 11 and the DC / DC converter 12 in the charging device 1 are bidirectional. When discharging the storage batteries 3 and 5, the output voltage converted in the reverse direction by the DC / DC converter 12 can be converted into an AC voltage by the AC / DC converter 11.
In the present embodiment and the embodiments described later, charging of the storage battery will be mainly described, but the same applies to discharging in the reverse direction.

  The connection device 2 includes switches S3 and S5 for opening and closing power lines corresponding to the storage batteries 3 and 5, and switches S4 and S6 for opening and closing communication lines corresponding to the BMSs 4 and 6. The output line of the DC / DC converter 12 branches and is connected to the storage batteries 3 and 5 via the switches S3 and S5. The lines connecting the communication unit 13 and the BMSs 4 and 6 are provided individually, and switches S4 and S6 are interposed in the middle.

  The switches S3 to S6 are controlled by a control unit (not shown) in the DC / DC converter 12. When the switch S3 is closed by the control, the switch S5 is open. Conversely, when the switch S5 is closed, the switch S3 is open. That is, the switch S3 and the switch S5 are controlled so as not to be closed at the same time. Therefore, either one of the storage batteries 3 and 5 is charged, and both are not charged at the same time. The communication switches S4 and S6 may be opened and closed in synchronization with the switches S3 and S6, respectively, but are not necessarily limited to such synchronized operations. That is, the switches S4 and S6 may be closed at the same time, or may be always closed for monitoring the storage batteries 3 and 5.

  In the power storage system 100 as described above, based on information from the BMS 4 or 6, the DC / DC converter 12 can close the switch S3 or S5 and charge the storage battery 3 or 5.

  In the power storage system 100 configured as described above, the plurality of storage batteries 3 and 5 are not simultaneously connected to the charging device 1. That is, a DC / DC converter corresponding to a storage battery for handling each storage battery individually as in the case where a plurality of storage batteries 3 and 5 are connected in parallel is not necessary, and the charging device 1 and the storage battery are connected via the connection device 2 only. 3 and 5 can be easily connected. Therefore, the DC / DC converter for each of the storage batteries 3 and 5 can be omitted, and the power storage system 100 having a simple and inexpensive circuit configuration can be obtained. Further, the omission of the DC / DC converter reduces the conversion loss correspondingly and contributes to the reduction of power loss as a whole. In addition, the charging device 1 can grasp the information of the connected storage batteries 3 and 5 and can control the DC / DC converter 12 appropriately by connecting the communication lines. Further, for example, overcharge and overdischarge of the storage batteries 3 and 5 can be prevented based on the information.

<< Second Embodiment >>
FIG. 2 is a single line connection diagram of the power storage system 100 according to the second embodiment. The difference from FIG. 1 is that the storage battery 3 is a stationary battery and the storage battery 5 is a storage battery mounted on an electric propulsion vehicle such as EV, PHEV, etc. (typically referred to as EV). In addition, the charging device 1 is provided with a DC / DC converter 14 that performs MPPT (Maximum Power Point Tracking) control for photovoltaic power generation. The photovoltaic power generation panel 8 is connected to the DC / DC converter 14, and the output of the DC / DC converter 14 is input to the DC / DC converter 12.

  Also in the power storage system 100 of FIG. 2, when the switch S3 is closed, the switch S5 is open. Conversely, when the switch S5 is closed, the switch S3 is open. That is, the switch S3 and the switch S5 are controlled so as not to be closed at the same time. Therefore, either one of the storage batteries 3 and 5 is charged, and both are not charged at the same time. The communication switches S4 and S6 may be opened and closed in synchronization with the switches S3 and S6, respectively, but are not necessarily limited to such synchronized operations. That is, the switches S4 and S6 may be closed at the same time, or may be always closed for monitoring the storage batteries 3 and 5.

  In the power storage system 100 as described above, based on information from the BMS 4 or 6, the DC / DC converter 12 can close the switch S3 or S5 and charge the storage battery 3 or 5.

  In the power storage system 100 configured as shown in FIG. 2, the same effects as those of the power storage system 100 in FIG. 1 can be obtained. Moreover, the configuration as shown in FIG. 2 is suitable when a charging system for the stationary storage battery 3 is added to the charging system for the storage battery 5 of the electric propulsion vehicle, and the storage capacity can be easily increased. For example, if the connecting device 2 is provided between the EV storage battery 5 and the charging device 1 that charges the storage battery 5 and the stationary storage battery 3 is added, the storage system 100 that can charge two types of storage batteries 3 and 5. Can be easily constructed.

  In addition, the power storage system 100 of FIG. 2 includes a solar power generation device (solar power generation panel 8, DC / DC converter 14). The output can be stored. Further, even when the EV storage battery 5 is out of the electric propulsion vehicle and disconnected from the power storage system 100, the remaining stationary storage battery 3 can be charged.

<< Third Embodiment >>
FIG. 3 is a single line connection diagram of the power storage system 100 according to the third embodiment. The difference from FIG. 2 is that the EV storage battery 5 is provided with a charging terminal 5d for DC charging and a charger 5a for AC charging. By connecting an AC electrical path to the charger 5a, it becomes possible to charge the battery using a household plug-in method.
Further, the connection device 2 is provided with a switch S7 that opens and closes an AC charging circuit, and the switch S7 is controlled to be opened and closed by the DC / DC converter 12. The AC charging circuit is connected to the commercial power supply 7.

  In the power storage system 100 configured as shown in FIG. 3, the same effects as those of the power storage system 100 of FIG. 1 can be obtained. 3 can charge the EV storage battery 5 and the stationary storage battery 3 simultaneously.

<< 4th Embodiment >>
FIG. 4 is a single line connection diagram of the power storage system 100 according to the fourth embodiment. The difference from FIG. 2 is that the DC / DC converter 12 from the BMS 4 is provided with a control power transfer circuit 9 and a backflow prevention diode 9d is provided on the circuit.
In this case, for example, even when the commercial system power supply 7 is out of power and solar power cannot be used (at night), the control power is provided from the BMS 4 to the charging device 1 and is switched by a command from the DC / DC converter 12. By closing S <b> 5 and S <b> 6, power is supplied to the charging device 1, and the EV storage battery 5 can be used as an emergency power source by reverse operation (discharging operation) of the charging device 1.

<< 5th Embodiment >>
FIG. 5 is a single-line connection diagram of the power storage system 100 according to the fifth embodiment. The difference from FIG. 1 is that the connection device 2 is provided inside the charging device 1. The connection device 2 can also be part of the charging device 1 in this way.
In this case, two output electric circuits are prepared directly from the charging device 1. For example, the state of the two storage batteries 3 and 5 can be grasped by always connecting the two storage batteries 3 and 5 to the charging device 1 and keeping the switches S4 and S6 closed at all times. Therefore, for example, during charging, if the charging device 1 detects the lower remaining amount of the connected storage batteries 3 and 5 by the communication unit 13, it is automatically connected to the lower remaining battery. It is easy to configure to switch between.

  2, 3, and 4, similarly, the connection device 2 can be taken into the charging device 1.

<< 6th Embodiment >>
FIG. 6 is a single-line connection diagram of the power storage system 100 according to the sixth embodiment. This is, for example, a practical configuration in which the connection device 2 in the configuration of FIG. 1 is replaced with a single charging cable 2c. The charging cable 2c is provided with a connector 2cn that can be commonly used for connection with the plurality of storage batteries 3 and 5 at the end. The connector 2cn of the charging cable 2c can physically connect only one storage battery. Then, by attaching or detaching the connector 2cn, one of the two storage batteries 3.5 can be charged. Since the charging cable 2c is one, the two storage batteries 3 and 5 are not charged simultaneously.
That is, in this case, the function of the connection device can be realized easily and reliably by the charging cable 2c.

<Others>
The circuit configurations of the above embodiments can be combined as appropriate. Moreover, although the stationary storage battery and the EV storage battery are illustrated in FIGS. 2 to 4, basically, the type of the storage battery is not limited as illustrated in FIG. 1.

In addition, as the circuit configuration of each of the above embodiments, the DC / DC converter is included in the charging device 1 alone, but the functions of the AC / DC converter and the DC / DC converter are combined into one. You can also.
For example, FIG. 7 is a single-line connection diagram of a power storage system 100 in which the charging device 1 in FIG. 1 is more generalized. The difference from FIG. 1 is that a converter 10 for converting a voltage / current provided from the external power supply PS into a predetermined DC voltage is provided in the charging device 1. Further, the converter 10 can convert the direct current power output from the storage battery 3 or 5 into desired alternating current power or direct current power at the time of a power failure of the external power source PS.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Charging device 2 Connection device 2c Charging cable 2cn Connector 3 Storage battery 4 BMS (Management device)
5 storage battery 5a charger 5d charging terminal 6 BMS (management device)
7 Commercial system power supply 8 Solar power generation panel 9 Electric circuit 9d Diode 10 Converter 11 AC / DC converter 12 DC / DC converter 13 Communication unit 14 Converter 100 Power storage system PS External power supply

Claims (7)

A charging device that receives power from an external power source and outputs DC power via a converter, and has a communication function;
A storage system comprising: a plurality of connectable storage batteries, and a connection device that connects a power line and a communication line to each other between any one of the storage batteries and a management device thereof and the charging device.   The power storage system according to claim 1, wherein the storage battery includes a stationary storage battery and a storage battery of an electric propulsion vehicle.   The power storage system according to claim 1, wherein the charging device includes a solar power generation device.   The power storage system according to claim 2, further comprising: an electric circuit that feeds power from the commercial power supply to the AC input charger mounted on the electric propulsion vehicle via the connection device.   The power storage system according to any one of claims 1 to 4, wherein the connection device is provided inside the charging device.   The power storage system according to any one of claims 1 to 5, wherein the connection device is a single charging cable having a connector that can be commonly used for connection with the plurality of storage batteries at the end.   The electrical storage system of Claim 2 provided with the electrical circuit which supplies a control power supply to the said charging device from the management apparatus provided accompanying the said stationary storage battery.

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