WO2020075301A1

WO2020075301A1 - Storage battery device

Info

Publication number: WO2020075301A1
Application number: PCT/JP2018/038198
Authority: WO
Inventors: 黒田　和人; 関野　正宏; 英生山崎; 岳史大澤; 敏彦正岡
Original assignee: 株式会社東芝
Priority date: 2018-10-12
Filing date: 2018-10-12
Publication date: 2020-04-16

Abstract

A storage battery device according to an embodiment of the present invention comprises: a first battery unit that comprises a plurality of battery cells connected in series, and that supplies power via a pair of first charging-discharging terminals; a second battery unit that comprises a plurality of battery cells connected in series, has one second charging-discharging terminal connected to the high-potential first charging-discharging terminal of the first battery unit, and supplies high-voltage power via the low-potential first charging-discharging terminal and a high-potential second charging-discharging terminal in tandem with the first battery unit; a first DC voltage converter that converts power, supplied from the first battery unit via the pair of first charging-discharging terminals, to DC voltage, and is capable of supplying low-voltage power; and a second DC voltage converter that converts power, supplied from the second battery unit via the pair of second charging-discharging terminals, to DC voltage, is connected to a low-voltage power supply terminal in parallel with the first DC voltage converter, and is capable of supplying low-voltage power. As a result, it is possible to simultaneously supply low-voltage power and high-voltage power while maintaining reliability.

Description

Storage battery

The embodiment of the present invention relates to a storage battery device.

In recent years, in automobiles, in order to increase the power consumption of electrical components and to utilize regenerative energy, the power supply voltage inside the vehicle has increased to 12 V, which has been generally used until now, for in-vehicle devices (auxiliaries) and electrical components. A study is underway to turn it into a voltage (36 to 48V). For example, a rated voltage of 48V can provide higher output and lower current consumption compared to existing 12V systems, thus increasing efficiency in some systems.

On the other hand, in order to utilize regenerative energy, the use of lithium-ion batteries is expanding as a storage element that can withstand repeated charging and discharging with a small capacity.

JP, 2009-277647, A JP, 2001-136735, A

However, since it takes time for all the in-vehicle equipment and electrical components to support high voltage, it is considered to supply both low voltage system power (12V system power) and high voltage system power. . On the other hand, low voltage system power (12V system power) is also expected as power for maintaining the minimum safety function required for a vehicle.

The present invention has been made in view of the above, and an object thereof is to provide a storage battery device capable of simultaneously supplying low-voltage system power and high-voltage system power while maintaining reliability.

The storage battery device of the embodiment is a storage battery device that is installed in a vehicle and supplies electric power to an in-vehicle device, and has a plurality of battery cells connected in series between a pair of first charging / discharging terminals. A first battery unit that supplies power via a first charge / discharge terminal, and a plurality of battery cells connected in series between a pair of second charge / discharge terminals, and a pair of second charge / discharge terminals are provided. While supplying electric power, one second charging / discharging terminal is connected to the first charging / discharging terminal on the high potential side of the first battery unit, and the first charging / discharging terminal on the low potential side cooperates with the first battery unit. And a second battery unit that supplies high-voltage system power via the second charging / discharging terminal on the high potential side, and a DC voltage conversion of the power supplied from the first battery unit via the pair of first charging / discharging terminals. And can supply low-voltage system power through the low-voltage system power supply terminal 1 DC voltage converter and DC voltage conversion of electric power supplied from the second battery unit via the pair of second charging / discharging terminals, and connected in parallel to the first DC voltage converter at the low voltage system power supply terminal And a second DC voltage converter capable of supplying low voltage system power via the low voltage system power supply terminal.

FIG. 1 is a schematic block diagram of a vehicle storage battery system according to an embodiment. FIG. 2 is a schematic configuration block diagram of the storage battery device. FIG. 3 is a schematic configuration diagram of the DC-DC converter. FIG. 4 is a processing flowchart of the embodiment.

Next, embodiments will be described in detail with reference to the drawings.
FIG. 1 is a schematic block diagram of a vehicle storage battery system according to an embodiment.
The vehicular storage battery system 10 functions as a generator 12G that is driven by the engine 11 and is capable of generating power, or functions as an electric motor (motor) 12M that is supplied with electric power and assists the driving of the engine 11. Power device 12, a storage battery device 13 that supplies power to the vehicle-mounted device, a controller 14 that measures the state of charge (voltage, charging current, and temperature) of the storage battery device 13 and controls the storage battery device 13, and a storage battery device. A first load group 15 to which low voltage system power (for example, 12V system power) is supplied from 13; and a second load group 16 to which high voltage system power (for example, 48V system power) is supplied from the storage battery device 13, Is equipped with.
In the above configuration, the electric power device 12 is included in the second load group 16 when it functions as the electric motor 12M.

Here, the configuration of the storage battery device 13 will be described.
FIG. 2 is a schematic configuration block diagram of the storage battery device.
The storage battery device 13 includes a control circuit 21 that controls the storage battery device 13 as a whole, a first battery unit 22 that mainly supplies low-voltage system power, and a state (SOC, voltage, charging current, and temperature) of the first battery unit 22. Status of the first monitoring circuit 23 that monitors and notifies the control result to the control circuit 21, the second battery unit 24 that cooperates with the first battery unit 22 to supply high-voltage power, and the state of the second battery unit 24. It has a second monitoring circuit 25 for monitoring (SOC, voltage, charging current and temperature) and notifying the control circuit 21 of the monitoring result, and an input / output terminal T1 and an input / output terminal T2. ) A first DC / DC converter 26 for performing conversion, a first input / output terminal T11 connected to the low potential side electrode of the first battery unit 22, and a second input / output terminal T11 connected to the high potential side electrode of the first battery unit 22. In and out A second DC / DC converter 27 having a terminal T21 and a second input / output terminal T22 connected to the high potential side terminal of the second battery unit 24, for performing DC / DC (direct current / direct current) conversion; The ground terminal TG connected to the low potential side electrode of the one battery unit 22 and the first input / output terminal T11, and the input / output terminal T1 of the first DC / DC converter 26 and the first input / output terminal T12 of the second DC / DC converter. A low voltage system power supply terminal TL to be connected, a high voltage system power supply terminal TH connected to one end of the circuit breaker 28, a start signal terminal TW to which a start signal WU is input from the controller 14 to the control circuit 21, The control circuit 21 includes a communication terminal TC for communicating with the controller 14.

In the above configuration, the first battery unit 22 and the second battery unit 24 have the same configuration, and a plurality of battery cells 30 are connected in series.

In the case of this configuration, for example, if the rated output voltage of the first battery unit 22 and the second battery unit 24 is 24 V, 24 V is output between the ground terminal TG and the second input / output terminal T2, and the first DC / The DC converter 26 performs DC / DC conversion (step-down) on this, and outputs 12V (low voltage system power) between the ground terminal TG and the low voltage system power supply terminal TL.
Similarly, 24V is output between the second input / output terminal T21 and the second input / output terminal T22, and 12V is output between the first input / output terminal T11 and the first input / output terminal T12. 48 V (high voltage system power) is output between the ground terminal TG and the high voltage system power supply terminal TH.

In the above configuration, the battery cell 30 is preferably a lithium-ion secondary battery or a nickel-hydrogen secondary battery because it has excellent output characteristics. Further, from the viewpoint of high weight energy density, the lithium ion secondary battery is more preferable.

Further, as the battery cell 30, among lithium ion secondary batteries, a positive electrode having a larger operating voltage range than the maximum voltage of the cell is an iron phosphate-based positive electrode and a negative electrode is a carbon-based lithium ion secondary battery or a positive electrode is 3d. A lithium ion secondary battery in which the negative electrode is a transition metal lithium oxide (eg, lithium manganate oxide, lithium nickel oxide, lithium cobalt oxide, etc.) and the negative electrode is lithium titanate oxide is more preferable.

Furthermore, when the smoothness of the negative electrode potential during charging / discharging is high, the potential difference between the cells is small, and the controllability of cross current and cell balance is excellent. Therefore, the above-mentioned positive electrode is a 3d transition metal lithium oxide (for example, lithium manganate oxide). , Lithium nickel oxide, lithium cobalt oxide), a ternary (eg, Li (Ni—Mn—Co) O ₂ ) lithium ion secondary battery in which a part of lithium cobalt oxide is replaced with nickel and manganese. However, a lithium ion secondary battery in which the negative electrode is a lithium titanate oxide (for example, Li ₄ Ti ₅ O ₁₂ ) is more preferable.

Here, the configuration of the battery cell 30 will be described in more detail.
In this case, a case where a lithium ion battery cell is used as the battery cell 30 will be described as an example.

A first mode of the battery cell 30 includes a lithium metal compound containing at least one metal element selected from the group consisting of cobalt, nickel and manganese, and the lithium metal compound is Li _a Ni _b Co _c Mn _d O. ₂ (provided that the molar ratios a, b, c and d are 0 ≦ a ≦ 1.1, b + c + d = 1) and a negative electrode containing a titanium-containing metal composite oxide. And a non-aqueous electrolyte containing a non-aqueous solvent.

A second mode of the battery cell 30 includes a lithium metal compound containing at least one metal element selected from the group consisting of cobalt, nickel and manganese, and the lithium metal compound is Li _a Ni _b Co _c Mn. a positive electrode having a positive electrode active material-containing layer represented by _d O ₄ (where molar ratios a, b, c and d are 0 ≦ a ≦ 1.1, b + c + d = 2), and a titanium-containing metal composite oxide. It is configured as a non-aqueous electrolyte secondary battery including a negative electrode containing the same and a non-aqueous electrolyte containing a non-aqueous solvent.

Further, in the case of configuring the battery cell 30 of the first and second aspects, the average particle diameter of the primary particles of lithium titanium oxide is 1 μm or less, and the specific surface area of the negative electrode layer by the BET method is 3 to 50 m ^2. It is desirable that it be in the range of / g.

Further, the lithium titanium oxide is represented by Li _{4 + x} Ti ₅ O ₁₂ (x is −1 ≦ x ≦ 3) or Li _{2 + x} Ti ₃ O ₇ (x is −1 ≦ x ≦ 3). desirable.
Furthermore, the titanium-containing metal composite oxide is a metal composite oxide containing Ti and at least one element selected from the group consisting of P, V, Sn, Cu, Ni and Fe. desirable.

Next, the configurations of the first DC / DC converter 26 and the second DC / DC converter 27 will be described.
In this case, since the first DC / DC converter 26 and the second DC / DC converter 27 have the same configuration, the second DC / DC converter 27 will be mainly described.

FIG. 3 is a schematic configuration diagram of the second DC-DC converter.
The second DC / DC converter 27 is a push-pull insulation type DC-DC converter, and includes an insulation transformer 31.

The first input / output terminal T12 connected to the first battery unit 22 is connected to the first intermediate tap 31T1 which is an intermediate tap on the primary winding side of the isolation transformer 31, and the first intermediate tap 31T1 is connected to the first battery unit 22 at one end thereof. One end of the switch 32 is connected, and one end of the second switch 33 is connected to the other end of the primary winding.

The other end of the first switch 32 and the other end of the second switch 33 are connected to the first input / output terminal T11, respectively.
Further, a current stabilizing capacitor 34 is connected between the first input / output terminal T11 and the first input / output terminal T12.

In addition, the second input / output terminal T22 connected to the second battery unit 24 is connected to the second intermediate tap 31T2, which is an intermediate tap on the secondary winding side of the insulation transformer 31, and is connected to one end of the secondary winding. Is connected to one end of a third switch 35 and the other end of the secondary winding is connected to one end of a fourth switch 36.
The other end of the third switch 35 and the other end of the fourth switch 36 are connected to the second input / output terminal T21, respectively.

Further, one end is connected to the second intermediate tap 31T2, and the coil 37 having the other end is connected to the second input / output terminal T22.
Furthermore, between the connection point between the coil 37 and the second input / output terminal T21 and between the second input / output terminal T22, a capacitor 38 that functions in cooperation with the coil 37 and functions as a low-pass filter is connected.

The second DC / DC converter 27 also includes a current sensor 39 for detecting an output current to the second battery unit 24, a control signal from the control circuit 21, a detected voltage of the first battery unit 22, and a detected second battery. A conversion operation circuit 40 that performs DC / DC conversion by controlling the first switch 32 to the fourth switch 36 based on the output current to the second battery unit 24 detected by the voltage and current sensor 39 of the unit 24. I have it.

Further, as indicated by the reference numeral in parentheses in FIG. 3, the input / output terminal T1 of the first DC / DC converter 26 corresponds to the first input / output terminal T12 of the second DC / DC converter 27, and the second DC / DC converter An input / output terminal (not shown) corresponding to the first input / output terminal T11 in 27 is connected to the ground terminal TG.
Similarly, the input / output terminal T2 of the first DC / DC converter 26 corresponds to the second input / output terminal T22 of the second DC / DC converter 27, and corresponds to the second input / output terminal T21 of the second DC / DC converter 27. The non-input / output terminal is connected to the ground terminal TG.

FIG. 4 is a processing flowchart of the embodiment.
The control circuit 21 determines whether or not the failure notification for notifying that the first battery unit 22 is in the failure state has been received from the first monitoring circuit 23 (step S11).

In the determination of step S11, when the failure notification notifying that the first battery unit 22 is in the failure state has not been received from the first monitoring circuit 23 (step S11; No), the control circuit 21 performs the second monitoring. It is determined whether or not a failure notification for notifying that the second battery unit 24 is in a failure state has been received from the circuit 25 (step S12).
In the determination of step S12, when the failure notification notifying that the second battery unit 24 is in the failure state has not been received from the second monitoring circuit 25 (step S12; No), the first DC / DC converter 26 and the The 2DC / DC converter 27 is driven and controlled to supply low-voltage system power (for example, 12V) from both (step S13).

As a result, even when the low-voltage system power is output and supplied by the first load group 15, the cell balance of the first battery unit 22 and the second battery unit 24 can be maintained similarly, and the first battery unit 22 and the second battery unit 22 can be maintained. Even when the two-battery unit 24 cooperates to supply high-voltage system power (for example, 48 V), it is possible to suppress a decrease in the effective storage capacity of the first battery unit 22 and the second battery unit 24.

Subsequently, the control circuit 21 determines whether or not the activation signal WU is being received from the ECU (not shown) of the vehicle body (step S14).

In the determination of step S14, when the activation signal WU is being received from the ECU (not shown) of the vehicle body (step S14; Yes), the control circuit 21 turns on the circuit breaker 28 (step S15).
As a result, low voltage system power (for example, 12V) is supplied between the ground terminal TG and the low voltage system power supply terminal TL, and at the same time, the ground terminal TG and the high voltage system power supply terminal TH are connected. In between, high voltage system power (for example, 48 V) is supplied.
Therefore, when the failure notification is not received from both the first monitoring circuit 23 and the second monitoring circuit 25, the first battery unit 22 and the high voltage system power are output regardless of whether the low voltage system power or the high voltage system power is output. Similarly, the cell balance of the second battery unit 24 can be maintained, and the reduction of the effective storage amount at the time of high-voltage system power output can be suppressed.

On the other hand, in the determination of step S14, when the activation signal WU is not being received from the ECU (not shown) of the vehicle body from the controller 14 (step S14; No), the breaker 28 is opened (or the open state is maintained). (Step S16), the process proceeds to step S11 again, and the above-described process is performed.

On the other hand, in the determination of step S11, when the failure notification for notifying that the first battery unit 22 is in the failure state is received from the first monitoring circuit 23 (step S11; Yes), the control circuit 21 causes the first DC The / DC converter 26 is stopped (step S17).
Next, the control circuit 21 determines whether or not the failure notification for notifying that the second battery unit 24 is in the failure state has been received from the second monitoring circuit 25 (step S18).

When it is determined in step S18 that the failure notification notifying that the second battery unit 24 is in the failure state has not been received from the second monitoring circuit 25 (step S18; No), the second DC / DC converter 27 is driven. Then, control is performed so as to supply low-voltage power (for example, 12 V) (step S19).
Therefore, at this time, it is possible to supply the low voltage system power via the ground terminal TG and the low voltage system power supply terminal TL.
Then, the process proceeds to step S22.
In the determination of step S18, when the failure notification notifying that the second battery unit 24 is in the failure state is received from the second monitoring circuit 25 (step S18; Yes), the control circuit 21 causes the second DC / DC. The converter 27 is stopped (step S25).
Therefore, at this time, the power supply is disabled.

In the determination of step S12, when the failure notification notifying that the second battery unit 24 is in the failure state is received from the second monitoring circuit 25 (step S12; Yes), the control circuit 21 causes the second DC / DC. The converter 27 is stopped (step S20).

In this case, since the failure notification notifying that the first battery unit 22 is in the failure state has not been received from the first monitoring circuit 23, the control circuit 21 drives the first DC / DC converter 26, Control is performed so as to supply low voltage system power (for example, 12 V) (step S21).

Subsequently, since the control circuit 21 cannot supply the high-voltage power, the control circuit 21 requests the controller 14 to open the circuit breaker 28 (step S22). It should be noted that the request for permitting the opening of the circuit breaker 28 is not performed when the cell voltage or the cell temperature is in a state immediately before the occurrence of the dangerous event, but the circuit breaker 28 is immediately opened.

Then, the control circuit 21 determines whether or not the controller 14 permits the circuit breaker 28 to open the circuit breaker (step S23).
If it is determined in step S23 that the controller 14 has not yet permitted the circuit breaker to open (step S23; No), the control circuit 21 again shifts the process to step S22 and enters the standby state.

When it is determined in step S23 that the controller 14 permits the circuit breaker to open (step S23; Yes), the control circuit 21 opens the circuit breaker 28 (step S24), and the process proceeds to step S11 again. To do.

As described above, according to the present embodiment, it is possible to supply the low voltage system power and the high voltage system power at the same time, and at least one of the first battery unit 22 and the second battery unit 24 is supplied. When the power cannot be supplied, it is possible to continue supplying the low-voltage power through the corresponding DC voltage converter (DC / DC converter), improving the reliability of the low-voltage power supply. Can be made.

Furthermore, the cell balance of the battery cells forming each of the first battery unit 22 and the second battery unit 24 due to the difference in the usage frequency of the first battery unit 22 and the second battery unit 24 can be constantly maintained, The charge / discharge capacity of the storage battery device, in particular, the charge / discharge capacity of high-voltage power can be secured for a long time.

The program executed by the storage battery device of the present embodiment is a file in an installable format or an executable format, and can be read by a computer such as a semiconductor storage device such as a CD-ROM, a DVD (Digital Versatile Disk), or a USB memory. It is provided by being recorded in a recording medium.

Further, the program executed by the storage battery device of the present embodiment may be stored in a computer connected to a network such as the Internet and provided by being downloaded via the network. In addition, the program executed by the storage battery device of the present embodiment may be provided or distributed via a network such as the Internet.
Further, the program executed by the storage battery device according to the present embodiment may be incorporated in a ROM or the like in advance and provided.

Although some embodiments of the present invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. These new embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the invention described in the claims and equivalents thereof.

Claims

A storage battery device mounted on a vehicle to supply electric power to an in-vehicle device,
A first battery unit having a plurality of battery cells connected in series between a pair of first charging / discharging terminals, and supplying electric power via the pair of first charging / discharging terminals;
A plurality of battery cells connected in series are provided between a pair of second charge / discharge terminals, and power is supplied via the pair of second charge / discharge terminals, and one of the second charge / discharge terminals is the first battery. One battery unit is connected to the first charge / discharge terminal on the high potential side, and cooperates with the first battery unit to connect the first charge / discharge terminal on the low potential side and the second charge / discharge terminal on the high potential side. A second battery unit for supplying high-voltage system power via
First DC voltage conversion capable of DC voltage conversion of electric power supplied from the first battery unit via the pair of first charging / discharging terminals, and supplying low voltage system electric power via the low voltage system electric power supply terminal A vessel,
DC voltage conversion of electric power supplied from the second battery unit via the pair of second charging / discharging terminals is performed, and the low voltage system power supply terminal is connected in parallel with the first DC voltage converter. A second direct-current voltage converter capable of supplying the low-voltage power through a low-voltage power supply terminal;
Storage battery device equipped with.
The first battery unit and the second battery unit have the same rated output voltage and rated power capacity,
Electric power that the first battery unit outputs via the pair of first charge / discharge terminals and the first DC voltage converter, and the second battery unit outputs the pair of second charge / discharge terminals and the second DC voltage. The output power through the converter, equipped with a control circuit to control the same,
The storage battery device according to claim 1.
In the first battery unit and the second battery unit, the same type of battery cells are used as the battery cells,
The storage battery device according to claim 2.
The first battery unit and the second battery unit have the same configuration,
The storage battery device according to claim 2 or 3.
A first monitoring circuit for monitoring the first battery unit;
A second monitoring circuit for monitoring the second battery unit;
A circuit breaker provided in a power supply path for supplying high-voltage power,
The control circuit, based on the monitoring results of the first monitoring circuit and the second monitoring circuit, when at least one of the first battery unit and the second battery unit is in a failure state, Open the circuit breaker,
The storage battery device according to claim 2 or 3.
The control circuit, based on the monitoring results of the first monitoring circuit and the second monitoring circuit, when at least one of the first battery unit and the second battery unit is in a failure state, Among the first DC voltage converter and the second DC voltage converter, the DC voltage converter corresponding to the battery unit in the failed state is put into an inoperative state.
The storage battery device according to claim 5.