JP7365883B2 - Connection device for power storage equipment - Google Patents

Description

The present application relates to a connection device for power storage equipment.

Conventional power storage systems used in industrial electrical equipment and the like are comprised of a plurality of built-in storage batteries or capacitors (hereinafter referred to as "power storage devices") and a control circuit. When the capacity of the power storage system increases or the built-in power storage equipment deteriorates, it is necessary to add or replace the power storage equipment. For example, when adding a new power storage device that does not store power, there is a risk that an inrush current will flow due to the potential difference with the existing power storage device. In order to avoid such problems, a system has been proposed in which a variable resistor and a resistance control section are used in the control circuit of the power storage system itself to reduce the rush current (see, for example, Patent Document 1).

JP2015-12725A (Figure 4)

However, conventional power storage systems must have a structure that incorporates the above-mentioned variable resistor and resistance control section into their own control circuit or the control circuit inside the power storage device, which poses the problem of increasing costs. Ta.

The present application was made in order to solve the above-mentioned problems, and the present application does not require a variable resistor and a resistance control section to be installed in the power storage system or the control circuit of the power storage device, and when adding or replacing the power storage device, the power storage device can be easily controlled. It is an object of the present invention to provide a connection device for power storage equipment that can be used to reduce inrush current between power storage devices and can be removed and used for other power storage systems after completion of expansion or replacement work.

The power storage device connection device disclosed in the present application is a connection device for connecting a second power storage device to a first power storage device in parallel, and the first power storage device is connected to a power supply terminal of the first power storage device. a second connection terminal connected to the power supply terminal of the second power storage device, and a first resistor connected between the first connection terminal and the second connection terminal; A potential difference detection circuit that detects a potential difference between the first connection terminal and the second connection terminal, and a display that displays the potential difference detected by the potential difference detection circuit, the display being indicated on the display. When the potential difference falls within a pre-calculated value range, the power terminal of the first power storage device and the power terminal of the second power storage device are connected, and the first connection terminal and the second connection are established. The terminal is removable .

When adding or replacing a second power storage device to a first power storage device, a first connection terminal connected to a power terminal of the first power storage device and a power terminal of the second power storage device a second connection terminal connected to the first connection terminal, a first resistor connected between the first connection terminal and the second connection terminal, and a second connection terminal connected to the first connection terminal and the second connection terminal; By using the device of the present application, which includes a potential difference detection circuit that detects the potential difference between the two, and a display that displays the potential difference detected by the potential difference detection circuit, it is possible to prevent intrusion between power storage devices when adding or replacing power storage devices. Connection work can be done with reduced current. Furthermore, when the potential difference between the power storage devices becomes close to 0, the power supply terminals of the power storage devices can be directly connected and the device of the present invention can be disconnected. Can be used in power storage systems.

1 is a block diagram showing the entire power supply equipment system according to Embodiment 1. FIG. FIG. 3 is a diagram illustrating a procedure for connecting power storage devices using the connection device according to the first embodiment. FIG. 3 is a diagram illustrating a procedure for connecting power storage devices using the connection device according to the first embodiment. FIG. 3 is a diagram illustrating a procedure for connecting power storage devices using the connection device according to the first embodiment. FIG. 3 is a diagram illustrating a procedure for connecting power storage devices using the connection device according to the first embodiment. FIG. 7 is a circuit diagram illustrating a state in which a connection device for a power storage device according to a second embodiment is connected. FIG. 7 is a circuit diagram showing a state in which a connection device for a power storage device according to a third embodiment is connected; 3 is a circuit diagram of a switching power supply circuit according to Embodiment 3. FIG.

Embodiment 1.
FIG. 1 is a block diagram showing the entire power supply equipment system according to the first embodiment. In FIG. 1, an AC commercial power source 1 is converted to DC by an AC/DC converter 2, and supplies power to a DC load 4, a power storage system 5, and a DC/AC converter 6 via a DC power line 3. do. Power is also supplied to an AC load 7 via a DC/AC converter 6 . The power storage system 5 is normally charged through the DC power line 3, and when the commercial power supply 1 is out of power, it is discharged through the DC power line 3 to back up the power for the DC load 4 and the AC load 7. In FIG. 1, the power storage system 5 includes a first power storage device 51, and a second power storage device 52 is currently being added using the connection device 8.

Hereinafter, a case where a second power storage device 52 is added to the first power storage device 51 of the power storage system 5 will be described as an example. However, when the number of power storage devices in the power storage system 5 is two or more from the beginning, or when replacing the power storage devices in the power storage system, the connection device 8 can be used in a similar manner.

2A to 2D are diagrams illustrating a connection procedure for adding a second power storage device 52 to a first power storage device 51 using the connection device 8 according to the first embodiment. FIG. 2A shows a state before the connection device 8 of the power storage device is connected. In this embodiment, the power terminals of the power terminal 511 of the first power storage device 51 and the power terminal 521 of the second power storage device 52 to be added are not directly connected. Therefore, in FIG. 2A, the connection device 8 is first placed between the power supply terminals 511 and 521.

Next, as shown in FIG. 2B, the first connection terminal 81 of the connection device 8 is connected to the power supply terminal 511, and the second connection terminal 82 is connected to the power supply terminal 521. The configuration and operation of the connection device 8 will be explained with reference to FIG. 2B. The connection device 8 includes a first resistor having a fixed resistance value R1 between a first connection terminal 81 on the first power storage device 51 side and a second connection terminal 82 on the second power storage device 52 side. It has a container 83. If the potential difference between the first power storage device 51 before expansion and the second power storage device 52 to be expanded is V1, the first power storage device 51 and the second power storage device are connected to this first resistor 83. 52, a current I1 flows from the first power storage device 51 to the second power storage device 52. This potential difference V1 is equal to the potential difference between the first connection terminal 81 and the second connection terminal 82 located at both ends of the first resistor 83, and is detected by the potential difference detection circuit 84 and displayed on the display 85.

The relationship between the resistance value of the first resistor 83 R1, the potential difference V1 across the first resistor 83, and the current I1 flowing through the first resistor 83 is I1=V1/R1. This current flows from either the first power storage device 51 or the second power storage device 52, whichever has a higher voltage to the lower one, charges the lower power storage device, and after a certain connection time T1, the first power storage device 51 or the second power storage device 52 is charged. The current flows until power storage device 51 and second power storage device 52 have the same potential.

If the power supply terminal 511 of the first electricity storage device 51 and the power supply terminal 521 of the second electricity storage device 52 are directly connected with the initial potential difference remaining without using this connection device 8, the initial current I1 will rush. It will flow as an electric current. If the initial potential difference V1 of the power storage device is 20V and the internal resistance of the power storage device is 0.1Ω, a current I1 of 200A will flow, and at the level of a normal electric wire, heating and fusing may occur. If the resistance value R1 of the first resistor 83 is 20 Ω, the rush current I1 flowing through the connecting device 8 can be suppressed to 1A. Therefore, by first connecting the first connection terminal 81 of the connection device 8 to the power supply terminal 511 of the first power storage device 51 and the second connection terminal 82 to the power supply terminal 521 of the second power storage device 52, The connection work to the connection device 8 can be performed while keeping the rush current I1 low.

The potential difference measured by the potential difference detection circuit 84 is displayed on a display 85. After connecting the connecting device 8, the value displayed on the display 85 is initially the initial potential difference V1 between the first power storage device 51 and the second power storage device 52, and then the value changes as time passes. It's decreasing. After the connection time T1 has elapsed, the potential difference V1 displayed on the display 85 becomes approximately 0.

In FIG. 2C, after confirming that the potential difference V1 displayed on the display 85 is approximately 0, the power terminal 511 of the first power storage device 51 and the power terminal 521 of the second power storage device 52 are connected to the connecting wire 53. Connect directly. Since the potential difference between the first power storage device 51 and the second power storage device 52 is approximately 0, the current flowing through the connection wire 53 during connection becomes small, and there is no problem in attaching the connection wire 53.

As a guideline for the potential difference V1 to be approximately 0 when connecting the connection line 53, the potential difference V1 is approximately ±0.1V, and the current flowing through the connection line 53 is approximately 1A. After connecting the connection wire 53, the first connection terminal 81 of the connection device 8 is removed from the power supply terminal 511, and the second connection terminal 82 is removed from the power supply terminal 521, so that the connection device 8 can be removed from the power storage system 5. Become. In this way, the work of adding the second power storage device 52 to the existing first power storage device 51 is completed while reducing the inrush current between the power storage devices.

In FIG. 2D, since the power terminal 511 of the first power storage device 51 and the power terminal of the second power storage device 52 are connected by the connection wire 53, the first connection terminal 81 of the connection device 8 is The second connection terminal 82 is disconnected from the power terminal 521 of the second power storage device 52 from the power terminal 511 of the power storage device 51 . In this way, the connecting device 8 can be removed after completing the expansion work, and thus can be used for the expansion work or replacement work of another power storage system.

The resistance value R1 of the first resistor 83 used in the connection device 8 satisfies R1>(Vmax) ² /W1, where Vmax is the maximum voltage of the power storage device. Here, W1 indicates the rated power value of the first resistor 83. However, since the surface temperature of the first resistor 83 becomes high when used at the rated power, R1=3×(Vmax) ² /W1 is calculated with a margin of about three times.

In the first embodiment, the case where the second power storage device 52 is added to the existing first power storage device 51 has been described, but the case where the first power storage device 51 is replaced with the second power storage device 52 is also explained. In the same procedure, by switching the circuit when the potential difference V1 becomes almost 0, the existing first power storage device 51 is replaced with a new second power storage device 52 while reducing the inrush current between the power storage devices. able to work.

Embodiment 2.
Embodiment 2 is a modification of Embodiment 1, and FIG. 3 is a circuit diagram showing a power storage device connection device 8 according to Embodiment 2. Embodiment 2 will be described assuming that a second power storage device 52 is added to the first power storage device 51 of the power storage system 5, as in the first embodiment. In FIG. 3, a bypass circuit 88 in which a switch 86 and a second resistor 87 are connected in series is added to the connection device 8 in parallel with the first resistor 83. The other configurations are the same as in the first embodiment.

When adding the second power storage device 52 to the power storage system 5 in addition to the first power storage device 51, first, the connection device 8 is connected. At this time, it is assumed that the switch 86 is open. The first connection terminal 81 of the connection device 8 is connected to the first power storage device 51, and then the second connection terminal 82 is connected to the second power storage device 52 to be newly connected. At this time, if there is a potential difference V1 between the first power storage device 51 and the second power storage device 52, the potential difference V1 is between the first connection terminal 81 and the second connection terminal 82, that is, the first resistance occurs at both ends of the vessel 83.

Assuming that the resistance value of the first resistor 83 is R1, when a potential difference V1 occurs between both ends of the first resistor 83, a current of I1=V1/R1 flows. This current flows from one of the first power storage device 51 and second power storage device 52 to the one with a higher voltage to the one with a lower voltage, and the lower power storage device is charged. Therefore, after a certain connection time T1, the second power storage device The current flows until the first power storage device 51 and the second power storage device 52 have the same potential.

At this time, as in the first embodiment, since the resistance value R1 of the first resistor 83 is sufficiently large, the connection work to the connection device 8 can be performed while keeping the rush current I1 low.

When the potential difference V1 is large, the connection time T1 becomes long, so in order to shorten this time, in the second embodiment, a bypass circuit 88 including a switch 86 and a second resistor 87 is provided. .

The potential difference measured by the potential difference detection circuit 84 is displayed on a display 85. After connecting the connecting device 8, the value displayed on the display 85 is initially the initial potential difference V1 between the first power storage device 51 and the second power storage device 52, and then the value changes as time passes. It's decreasing. The switch 86 is closed when the potential difference V1 displayed on the display 85 decreases to a predetermined potential difference V2.

Closing switch 86 causes a current I2 to flow through second resistor 87. That is, after connecting the connecting device 8, measure the potential difference V1 displayed on the display 85, and close the switch 86 when the potential difference drops to a predetermined potential difference V2, thereby increasing the current flowing through the connecting device 8 to I1+I2, and reducing the potential difference. The connection time T1 at which V1 becomes 0 can be accelerated. When the switch 86 is closed, the first resistor 83 and the second resistor 87 are connected in parallel, and if the second resistor 87 has a fixed resistance value R2, the combined resistance value is R1× R2/(R1+R2).

Thereafter, after the potential difference V1 of the display device 85 becomes approximately 0, the process is similar to that in Embodiment 1, so a description thereof will be omitted.

Note that the resistance value R2 of the second resistor 87 is determined by the same method as the resistance value R1 derived in the first embodiment. From the relationship between the potential difference V2 between the first power storage device 51 and the second power storage device 52 at the timing of closing the switch 86 and the rated power value W2 of the second resistor 87, R2>(V2) ² /W2. . In addition, the resistance value becomes about three times as high considering the temperature rise, and becomes R2=3×(V2) ² /W2.

Further, the larger the potential difference V2 that closes the switch 86, the shorter the connection time T1 can be, and is determined by the resistance value R2 of the second resistor 87 as V2=√(R2×W2/3).

Therefore, according to Embodiment 2 of the present application, in addition to the effects described in Embodiment 1, it is possible to shorten the connection time T1 at which the potential difference is approximately 0. This has the effect of shortening the time required to complete the work.

Further, in the second embodiment, a case is shown in which there is one bypass circuit 88, but a plurality of bypass circuits 88 may be provided in parallel. Although it increases the cost, by increasing the number of resistors using the bypass circuit 88, it becomes possible to deal with a wider range of potential differences.

Furthermore, in the second embodiment, the resistance value of the second resistor is fixed, but a variable resistor may be used. In that case, instead of the switch 86, the resistance value is variable according to the potential difference V1. A control device may be installed to control the resistance value of the resistor. This allows the resistance value to be switched more smoothly. Further, the same effect can be obtained even if a variable resistor is used as the first resistor of the first embodiment.

In the second embodiment, it is assumed that the operator operates the switch 86, but the potential difference detection circuit 84 is provided with a function of determining the potential difference V1, and the switch is automatically activated when V1 becomes equal to or less than V2. An automatic circuit for closing 86 may be provided. Further, when the number of resistors is increased or when the resistors are replaced with variable resistors, the automatic circuit using the potential difference detection circuit 84 may similarly be used for control. By automating the process, it is possible to save the effort of monitoring changes in the potential difference V1 using the display 85.

Embodiment 3.
Embodiment 3 is a modification of Embodiment 1, and FIG. 4 is a circuit diagram showing a connection device 8 between a power storage system and a power storage device according to Embodiment 3. Embodiment 3 will be described assuming that a second power storage device 52 is added to the first power storage device 51 of the power storage system 5, as in the first embodiment. In FIG. 4, the connecting device 8 is provided with a switching power supply circuit 90 instead of the first resistor 83. The other configurations are the same as in the first embodiment.

Switching power supply circuit 90 functions similarly to first resistor 83 in the first embodiment. That is, it functions to eliminate the potential difference between the first power storage device 51 and the second power storage device 52. FIG. 5 shows a circuit diagram of the switching power supply circuit 90. In FIG. 5, a switching power supply circuit 90 includes switch elements 91, 92, 93, and 94, diodes 95, 96, 97, and 98, an inductor 99, and a power supply that controls the switch elements 91 to 94 according to a predetermined program. It is composed of a control section 100.

In FIG. 5, the operation of the power supply control unit 100 when supplying current from the first connection terminal 81 to the second connection terminal 82 is as follows. First, switch elements 91 and 93 are turned on, and current is supplied from first connection terminal 81 to inductor 99 to store magnetic energy. Next, when switch elements 91 and 93 are turned off, the magnetic energy stored in inductor 99 is supplied as a current to second connection terminal 82 through diodes 96 and 98. Furthermore, when supplying current from the second connection terminal 82 to the first connection terminal 81, the current is supplied by the switch elements 92 and 94 and the diodes 95 and 97. In this way, energy transfer by current occurs without loss of energy.

If the switching power supply circuit 90 shown above is used in the connection device 8, the magnitude of the current flowing through the inductor 99 can be controlled by changing the on/off time of the switching elements 91 to 94, so that the inrush current The connection work to the connection device 8 can be performed while keeping I1 low. Thereafter, the power supply control unit 100 controls the current so that the current flows from the higher voltage to the lower one of the first power storage device 51 and the second power storage device 52, thereby charging the lower power storage device. After a certain connection time T1, current can be allowed to flow until the potential difference between the first power storage device 51 and the second power storage device 52 becomes approximately zero. Further, a potential difference detection circuit 84 that detects the potential difference between the first connection terminal 81 and the second connection terminal 82 is linked to the power supply control unit 100 to reduce the initial inrush current when the potential difference is large, and increase the subsequent current. By controlling the power supply control unit 100 in this way, it becomes possible to shorten the connection time T1 as in the second embodiment.

After the potential difference V1 of the display device 85 becomes approximately 0, the process is the same as in the first embodiment, so a description thereof will be omitted.

As described above, since the switching power supply circuit 90 is used in the third embodiment, it has the characteristic of transferring energy more efficiently than the case where the first resistor 83 is used. Energy loss is reduced. Furthermore, it becomes possible to shorten the connection time T1 during which the potential difference becomes approximately 0, thereby bringing about the effect of shortening the time required to complete the work.

Therefore, according to Embodiment 3 of the present application, in addition to the effects shown in Embodiments 1 and 2, a connection device for power storage equipment with less energy loss can be obtained.

In each of the embodiments of the present application, a storage battery is used as the power storage device, but it goes without saying that a similar circuit can be constructed using a device that stores electricity, such as a capacitor or a capacitor, and the same effect can be obtained. do not have. Furthermore, a fuse or a circuit breaker may be added as appropriate to protect the component devices when an overcurrent flows through each circuit.

In addition, in the first to third embodiments, it was explained that the potential difference V1 is confirmed by the operator using the display 85, but instead of the display 85, a notification sound such as a buzzer indicating that the potential difference has become almost 0 is used. It is also possible to provide a notification device that emits a notification signal using voice guidance, flashing indicator lights, etc., or a combination thereof. In that case, the connection work by the operator can be carried out more efficiently.

Although this application describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments may be applicable to a particular embodiment. The present invention is not limited to, and can be applied to the embodiments alone or in various combinations. Accordingly, countless variations not illustrated are envisioned within the scope of the technology disclosed herein. For example, this includes cases where at least one component is modified, added, or omitted, and cases where at least one component is extracted and combined with components of other embodiments.

1 commercial power supply, 2 AC/DC converter, 3 DC power line, 4 DC load, 5 electricity storage system, 51 first electricity storage device, 511 power supply terminal, 52 second electricity storage device, 521 power supply terminal, 6 DC/AC Converter, 7 AC load, 8 Connection device, 81 First connection terminal, 82 Second connection terminal, 83 First resistor, 84 Potential difference detection circuit, 85 Display, 86 Switch, 87 Second resistor , 88 bypass circuit, 90 switching power supply circuit, 91, 92, 93, 94 switch element, 95, 96, 97, 98 diode, 99 inductor, 100 power supply control section

Claims (10)

A connection device for connecting a second power storage device to a first power storage device in parallel,
a first connection terminal connected to a power supply terminal of the first power storage device;
a second connection terminal connected to the power supply terminal of the second power storage device;
a first resistor connected between the first connection terminal and the second connection terminal;
a potential difference detection circuit that detects a potential difference between the first connection terminal and the second connection terminal;
a display that displays the potential difference detected by the potential difference detection circuit;
Equipped with
When the potential difference shown on the display falls within a pre-calculated value range, the power terminal of the first power storage device and the power terminal of the second power storage device are connected to the first connection terminal. and a connection device for a power storage device, wherein the second connection terminal is removably provided . A connection device for connecting a second power storage device to a first power storage device in parallel,
a first connection terminal connected to a power supply terminal of the first power storage device;
a second connection terminal connected to the power supply terminal of the second power storage device;
a first resistor connected between the first connection terminal and the second connection terminal;
a potential difference detection circuit that detects a potential difference between the first connection terminal and the second connection terminal;
a notification device that issues a notification signal in response to the potential difference detected by the potential difference detection circuit;
Equipped with
Connecting the power supply terminal of the first power storage device and the power supply terminal of the second power storage device to the second power storage device in response to a notification signal issued by the notification device indicating that the potential difference has fallen within a pre-calculated value range. A connection device for a power storage device , wherein one connection terminal and the second connection terminal are removably provided . The connection of the power storage device according to claim 1 or 2, further comprising a bypass circuit in which a switch and a second resistor are connected in series between the first connection terminal and the second connection terminal. Device. 4. The power storage device connection device according to claim 3, wherein a plurality of said bypass circuits are provided in parallel. 5. The power storage device connection device according to claim 3, further comprising a control device that closes the switch of the bypass circuit in accordance with the potential difference detected by the potential difference detection circuit. 3. The power storage device connection device according to claim 1, wherein the first resistor is a variable resistor. 4. The power storage device connection device according to claim 3, wherein the second resistor is a variable resistor. 8. The power storage device connection device according to claim 6, further comprising a control device that changes the resistance value of the variable resistor according to the potential difference detected by the potential difference detection circuit. A connection device for connecting a second power storage device to a first power storage device in parallel,
a first connection terminal connected to a power supply terminal of the first power storage device;
a second connection terminal connected to the power supply terminal of the second power storage device;
a switching power supply circuit connected between the first connection terminal and the second connection terminal;
a potential difference detection circuit that detects a potential difference between the first connection terminal and the second connection terminal;
a display that displays the potential difference detected by the potential difference detection circuit;
Equipped with
When the potential difference shown on the display falls within a pre-calculated value range, the power terminal of the first power storage device and the power terminal of the second power storage device are connected to the first connection terminal. and a connection device for a power storage device, wherein the second connection terminal is removably provided . A connection device for connecting a second power storage device to a first power storage device in parallel,
a first connection terminal connected to a power supply terminal of the first power storage device;
a second connection terminal connected to the power supply terminal of the second power storage device;
a switching power supply circuit connected between the first connection terminal and the second connection terminal;
a potential difference detection circuit that detects a potential difference between the first connection terminal and the second connection terminal;
a notification device that issues a notification signal in response to the potential difference detected by the potential difference detection circuit;
Equipped with
Connecting the power supply terminal of the first power storage device and the power supply terminal of the second power storage device to the second power storage device in response to a notification signal issued by the notification device indicating that the potential difference has fallen within a pre-calculated value range. A connection device for a power storage device , wherein one connection terminal and the second connection terminal are removably provided .

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