JP7200915B2 - storage system - Google Patents

Description

TECHNICAL FIELD This disclosure relates to a power storage system, and more particularly to a power storage system suitable for preventing damage to a monitoring device.

Conventionally, as shown in FIG. 9, a main battery 2' including power storage units BC(1)' to BC(N)', which are a plurality of cells connected in series, and power storage units BC(1)' to BC( N)', a battery monitoring unit 22' of the battery ECU 20', and a plurality of voltage detection lines L( 0)′ to L(N)′ (see, for example, Patent Document 1). The voltage detection lines L(0)' to L(N)' are provided with fuses FU(0)' to FU(N)', respectively.

JP 2016-134962 A

However, in the power storage system 1' as disclosed in Patent Document 1, due to the influence of submersion in water, etc., the fuse FU(0)' on one end side of the power storage units BC(1)' to BC(N)' connected in series and the other fuse FU(0)' If the fuse FU(N)' on the end side is left and the other fuses are blown, the battery ECU 20' will receive a high voltage (in FIG. The added voltage of the main battery 2' is applied, and there is a possibility that the internal circuit of the battery ECU 20' is damaged.

This disclosure has been made to solve the above-described problems, and an object thereof is to provide a power storage system capable of preventing damage to the monitoring device.

A power storage system according to this disclosure includes an assembled battery in which a plurality of battery units are connected in series, a monitoring device that monitors the voltage of the battery units, a plurality of voltage detection lines that respectively connect the battery units to the monitoring device, and a plurality of interrupters provided for each of the plurality of voltage detection lines and capable of interrupting the current flowing through the voltage detection lines. The plurality of circuit breakers are set to have a large current when the circuit breaker interrupts the current in order from the circuit breaker at one end of the battery units connected in series to the circuit breaker at the other end.

According to such a configuration, when the current flowing through the voltage detection line connecting the assembled battery and the monitoring device is interrupted, the current at the other end where the interrupting device interrupts the current is set to be small. The current is interrupted in order from the interrupting device toward the interrupting device on the one end side to which the current is set to be large when the interrupting device interrupts the current. Therefore, it is possible to prevent a large current from flowing through the monitoring device. As a result, it is possible to provide a power storage system capable of preventing damage to the monitoring device.

According to this disclosure, it is possible to provide an electricity storage system capable of preventing damage to the monitoring device.

1 is a circuit diagram showing a configuration of a vehicle equipped with a power storage system according to this embodiment; FIG. 2 is a circuit diagram showing the outline of the configuration of a main battery and a battery ECU of this embodiment; FIG. FIG. 10 is a first diagram showing an example of the flow of blowing a fuse when a short circuit occurs in this embodiment; FIG. 10 is a second diagram showing an example of the flow of blowing a fuse when a short circuit occurs in this embodiment; FIG. 11 is a third diagram showing an example of the flow of blowing a fuse when a short circuit occurs in this embodiment; FIG. 11 is a fourth diagram showing an example of the flow of blowing of a fuse when a short circuit occurs in this embodiment; FIG. 11 is a fourth diagram showing an example of the flow of blowing of a fuse when a short circuit occurs in this embodiment; FIG. 5 is a circuit diagram showing the outline of the configuration of a main battery and a battery ECU of a second embodiment; FIG. 10 is a diagram showing an example of melting of a fuse when a conventional short circuit occurs.

[First embodiment]
Hereinafter, embodiments of the disclosure will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

FIG. 1 is a circuit diagram showing the configuration of a vehicle equipped with a power storage system 1 according to this embodiment. Referring to FIG. 1, the vehicle includes a main battery 2 as a power storage device, a battery ECU (Electronic Control Unit) 20, a system main relay 4, an auxiliary DC/DC converter 6, a voltage converter 12, It includes a smoothing capacitor 3 , voltage sensors 13 and 21 , a vehicle driving section 14 and a control device 30 .

The vehicle drive unit 14 includes a vehicle drive motor, an engine, a gear mechanism, drive wheels, and the like. Voltage converter 12 is provided between main battery 2 and vehicle drive unit 14 and performs voltage conversion. Auxiliary equipment DC/DC converter 6 steps down the voltage (for example, 200 V) of main battery 2 and supplies the auxiliary equipment load circuit with a DC voltage (for example, 14 V) as a power supply voltage.

Voltage sensor 21 detects voltage VL across smoothing capacitor 3 and outputs it to control device 30 . Voltage converter 12 boosts the voltage across the terminals of smoothing capacitor 3 when main battery 2 is discharged. Voltage sensor 13 detects voltage VH boosted by voltage converter 12 and outputs it to control device 30 .

System main relay 4 is controlled to be in a conducting/non-conducting state in accordance with a control signal provided from control device 30 .

Battery ECU 20 includes a current sensor that detects a current IB flowing through main battery 2 and a voltage sensor that detects a voltage VB of the main battery in order to monitor the state of charge of main battery 2 .

Voltage converter 12 is controlled by control device 30 to operate as a step-down circuit when power is generated by the engine or by braking by the motor in vehicle drive unit 14 . At this time, main battery 2 is charged.

FIG. 2 is a circuit diagram showing a schematic configuration of main battery 2 and battery ECU 20 of this embodiment. Referring to FIG. 2 , power storage system 1 includes a main battery 2 and a battery ECU 20 . Main battery 2 includes a plurality of power storage units BC(1) to BC(N) connected in series. As the power storage units BC(1) to BC(N), for example, secondary batteries such as lead-acid batteries, nickel-hydrogen batteries, and lithium-ion batteries, and single batteries such as large-capacity capacitors such as electric double-layer capacitors can be used. can. Battery ECU 20 includes Zener diodes D( 1 ) to D(N) and a battery monitoring unit 22 .

A voltage detection line L(M−1) connects between the power storage units BC(M−1) and BC(M) and the battery monitoring unit 22 . Voltage detection line L(M) connects between power storage units BC(M) and BC(M+1) and battery monitoring unit 22 . The same applies to the other voltage detection lines L(1) to L(M-2) and L(M+1) to L(N).

Fuses FU(0) to FU(N) are provided on voltage detection lines L(0) to L(N), respectively. It cuts off the current by being fused. The rated current value is the allowable current value for each of the fuses FU(0) to FU(N). Thus, the battery ECU 20 is protected by providing the fuses FU(0) to FU(N).

[Characteristics of this disclosure]
In the power storage system 1 described above, under the influence of a situation in which the voltage detection lines L(0) to L(N) are short-circuited (for example, submerged in water), the power storage units BC(1) to BC(N) connected in series If the fuse FU(0) on one end and the fuse FU(N) on the other end of the battery ECU 20 are blown, a high voltage (storage units BC(1) to BC(N)) is applied to the battery ECU 20. voltage of the main battery 2) is applied, and there is a risk that the internal circuit of the battery ECU 20 will be damaged.

Therefore, the plurality of fuses FU(0) to FU(N) are sequentially connected from the fuse on one end of the power storage units BC(1) to BC(N) connected in series to the fuse on the other end. Set a large current when the fuse cuts off the current.

Thus, when the current flowing through the voltage detection lines L(0) to L(N) connecting the main battery 2 and the battery ECU 20 is interrupted, the current at which the fuse interrupts the current is set small. Current is interrupted in order from the fuse on the other end side to the fuse on the one end side, which is set to have a large current when the fuse interrupts the current. Therefore, it is possible to prevent a large current from flowing through the battery ECU 20 . As a result, damage to the battery ECU 20 can be prevented.

Referring back to FIG. 2, in this disclosure, a plurality of fuses FU(0)-FU(N) are connected from fuse FU(N) at one end of power storage units BC(1)-BC(N) to fuse FU(N) at the other end. A larger current is set in order toward the fuse FU(0) on the end side when the fuse cuts off the current.

That is, of fuse FU(0) to fuse FU(N), fuse FU(0) is the most difficult to blow, fuse FU(N) is the easiest to blow, and fuse FU(0) to fuse FU(N) It is made easy to melt in the order of going to.

FIGS. 3 to 7 are first to fifth diagrams respectively showing an example of the blowing flow of fuses FU(0) to FU(N) when a short circuit occurs in this embodiment. Referring to FIG. 3, when voltage detection lines L(1) to L(N) are all short-circuited, a current path including at least one of power storage units BC(1) to BC(N) ( For example, a current flows along the path indicated by current I in FIG.

The positive terminal side of the storage unit BC(N) has the highest potential in the main battery 2 . Therefore, after the short circuit occurs, the current I first flows from the positive terminal side of the power storage unit BC(N). Then, the flowing current I flows from the voltage detection line L(N) to the voltage detection line L(N−1) from the short-circuited portion inside the battery ECU 20 or outside the battery ECU 20 .

Referring to FIG. 4, when the current value of current I exceeds the rated current value of fuse FU(N), this rated current value is made lower than the rated current value of fuse FU(N−1). Therefore, the fuse FU(N-1) is not blown, but the fuse FU(N) is blown.

Referring to FIG. 5, when fuse FU (M+2) is melted, the positive terminal side of power storage unit BC (M+1) is the highest in main battery 2 . Therefore, the current II flows from the positive terminal side of the power storage unit BC(M+1). Then, the current II that has flowed out flows from the voltage detection line L(M+1) to the voltage detection line L(M) from the short-circuited location inside the battery ECU 20 or outside the battery ECU 20 .

When the current value of the current II exceeds the rated current value of the fuse FU(M+1), the rated current value is lower than the rated current value of the fuse FU(M), so the fuse FU(M) The fuse FU(M+1) is blown without blowing.

Referring to FIG. 6, when fuse FU(2) is melted, the positive terminal side of power storage unit BC(1) is the highest in main battery 2. Referring to FIG. Therefore, the current III flows from the positive terminal side of the power storage unit BC(1). Then, the current III that has flowed out flows from the voltage detection line L(1) to the voltage detection line L(0) from the short-circuited location inside or outside the battery ECU 20 .

Referring to FIG. 7, when the current value of current III exceeds the rated current value of fuse FU(1), this rated current value is lower than the rated current value of fuse FU(0). , fuse FU(0) is not blown, but fuse FU(1) is blown. After that, a short circuit causes a potential difference across the fuse FU(0), and when the current value due to this potential difference exceeds the rated current value of the fuse FU(0), the fuse FU(0) is blown.

In this manner, the fuses FU(0) to FU(N) are blown in order from the fuse FU(N) to the fuse FU(0). As a result, the battery ECU 20 is not subjected to the full voltage of the main battery 2, which is the sum of the voltages of the power storage units BC(1) to BC(N), for a long period of time, thereby preventing the battery ECU 20 from being damaged. .

[Second embodiment]
In the first embodiment, the voltage detection lines L(0) to L(N) are provided with fuses FU(0) to FU(N), respectively. In the second embodiment, voltage detection lines L(0) to L(N) are provided with resistance elements R(0) to R(N) in addition to fuses FU(0) to FU(N), respectively. make it

Further, in the first embodiment, the plurality of fuses FU(0) to FU(N) are arranged from the fuse FU(N) on one end of the power storage units BC(1) to BC(N) to the fuse on the other end. In order toward FU(0), a larger current is set when the fuse cuts off the current.

In the second embodiment, it is assumed that the fuses FU(0) to FU(N) have the same current value when breaking the current, that is, have the same fusing characteristics. On the other hand, resistance elements R(0) to R(N) move from resistance element R(N) on one end side of power storage units BC(1) to BC(N) toward resistance element R(0) on the other end side. in order to increase the resistance value.

FIG. 8 is a circuit diagram showing a schematic configuration of the main battery 2 and the battery ECU 20 of the second embodiment. Referring to FIG. 8, power storage system 1A of the second embodiment includes main battery 2 and battery ECU 20, like power storage system 1 of the first embodiment.

A voltage detection line L(M−1) connects between the power storage units BC(M−1) and BC(M) and the battery monitoring unit 22 . Voltage detection line L(M) connects between power storage units BC(M) and BC(M+1) and battery monitoring unit 22 . The same applies to the other voltage detection lines L(1) to L(M-2) and L(M+1) to L(N).

Fuses FU(0) to FU(N) and resistance elements R(0) to R(N) are provided in voltage detection lines L(0) to L(N), respectively, and fuses FU(0) to FU( When the current flowing through N) exceeds the rated current value, the current is interrupted by fusing. In the second embodiment, the fuses FU(0) to FU(N) have the same rated current value. On the other hand, resistance elements R(0) to R(N) move from resistance element R(N) on one end side of power storage units BC(1) to BC(N) toward resistance element R(0) on the other end side. The resistance value is set to be large in order.

As a result, a plurality of breaking devices configured by combinations of the fuses FU(0) to FU(N) and the resistance elements R(0) to R(N) of the second embodiment are equivalent to the fuses of the first embodiment. Similar to the plurality of circuit breakers respectively composed of FU(0) to FU(N), the circuit breakers are arranged in order from the circuit breaker at one end of the storage units BC(1) to BC(N) to the circuit breaker at the other end. In addition, the current is set large when the interrupting device interrupts the current.

In other words, the fuse FU(0) and resistor FU(0) and resistor The breaking device made up of the element (0) is the most difficult to blow, the breaking device made up of the fuse FU (N) and the resistance element R (N) is the easiest to blow, and the fuse FU (0) and the resistance element R ( 0) to the breaking device made up of the fuse FU(N) and the resistance element R(N).

As a result, in the second embodiment, as in the first embodiment, the cutoff device composed of the fuse FU(N) and the resistance element R(N) is switched to the fuse FU(0) and the resistance element R(0). The isolator blows in order towards the configured isolator. As a result, the battery ECU 20 is not subjected to the full voltage of the main battery 2, which is the sum of the voltages of the power storage units BC(1) to BC(N), for a long period of time, thereby preventing the battery ECU 20 from being damaged. .

[Modification]
(1) In the above-described embodiment, as described with reference to FIG. 2, the power storage units BC(0) to BC(N) are composed of single cells. However, without being limited to this, the power storage units BC(0) to BC(N) may be formed by connecting a plurality of cells in parallel.

(2) In the above-described embodiment, battery ECU 20 includes Zener diodes D(1) to D(N) and battery monitoring unit 22 . However, the battery ECU 20 is not limited to this, and may have any configuration as long as it can detect the voltage between the voltage detection lines L(0) to L(N). configuration may be used.

(3) In the above-described embodiments, in the first embodiment, the plurality of fuses FU(0) to FU(N) are the fuses FU on one end side of the power storage units BC(1) to BC(N). A larger current is set in order from (N) toward the fuse FU(0) on the other end side when the fuse cuts off the current.

Further, in the second embodiment, a plurality of breaker devices each composed of a combination of fuses FU(0) to FU(N) and resistance elements R(0) to R(N) are provided in the power storage unit BC(1). ) to BC(N), the current is set to be large when the current is interrupted by the interrupting device in order from the interrupting device on the one end side to the interrupting device on the other end side.

However, it is not limited to this, and a plurality of circuit breakers are arranged in order from the circuit breaker on the one end side of the battery units connected in series to the circuit breaker on the other end side, and when the circuit breaker blocks the current. Other configurations may be used as long as the current is set large.

Specifically, in the second embodiment, the fuses FU(0) to FU(N) have the same rated current value. However, a plurality of breaker devices configured by respective combinations of fuses FU(0) to FU(N) and resistance elements R(0) to R(N) are used for power storage units BC(1) to BC(N). If the current is set to be large when the current is interrupted by the circuit breaker in order from the circuit breaker on one end to the circuit breaker on the other end, the ratings of the fuses FU(0) to FU(N) The current values may not be the same. For example, in the second embodiment, as in the first embodiment, the plurality of fuses FU(0) to FU(N) are the fuses FU ( N) to the fuse FU(0) on the other end side, the current when the fuse cuts off the current may be set to be large.

(4) In the above-described embodiment, as shown in FIG. 1, the power storage system 1 is included in the vehicle. However, the power storage system 1 is not limited to this, and the power storage system 1 may be included in another machine different from the vehicle, or may be used alone without being included in the machine.

[summary]
(1) As shown in FIGS. 2 and 8, the power storage system 1, 1A includes a main battery 2 in which a plurality of power storage units BC(1) to BC(N) are connected in series, and a power storage unit BC(1). to BC(N); a plurality of voltage detection lines L(0) to L(N) connecting the battery ECU 20 to the power storage units BC(1) to BC(N); A plurality of breakers are provided in each of the plurality of voltage detection lines L(0) to L(N) and capable of interrupting the current flowing through the voltage detection lines L(0) to L(N). As shown in FIGS. 2 and 8, the circuit breakers are arranged in order from the circuit breaker at one end of the power storage units BC(1) to BC(N) connected in series to the circuit breaker at the other end. , the current is set large when the interrupter interrupts the current.

As a result, when the current flowing through the voltage detection lines L(0) to LO(N) connecting the main battery 2 and the battery ECU 20 is interrupted, the current at which the interrupting device interrupts the current is set small. The current is interrupted in order from the interrupting device on the other end side where the current is interrupted to the interrupting device on the one end side to which the current is set to be large when the interrupting device interrupts the current. Therefore, it is possible to prevent a large current from flowing through the battery ECU 20 . As a result, damage to the battery ECU 20 can be prevented.

(2) As shown in FIG. 2 of the first embodiment, the breaker is fuses FU(0) to FU(N).

(3) As shown in FIG. 8 of the second embodiment, the breaker is a combination of fuses FU(0) to FU(N) and resistance elements R(0) to R(N).

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present disclosure is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning of equivalents of the scope of the claims.

Reference Signs List 1, 1A power storage system, 2 main battery, 3 smoothing capacitor, 4 system main relay, 6 auxiliary DC/DC converter, 12 voltage converter, 13, 21 voltage sensor, 14 vehicle drive unit, 20 battery ECU, 22 battery Monitoring Unit, 30 Controller, BC(0) to BC(N) Storage Unit, D(1) to D(N) Zener Diode, FU(0) to FU(N) Fuses, L(0) to L(N) ) voltage detection lines, R(0) to R(N) resistive elements.

Claims (1)

an assembled battery in which a plurality of battery units are connected in series;
a monitoring device that monitors the voltage of the battery unit;
a plurality of voltage detection lines respectively connecting between the battery units and the monitoring device;
a plurality of interrupting devices provided in each of the plurality of voltage detection lines and capable of interrupting current flowing through the voltage detection lines;
The plurality of interrupting devices are arranged in order from the interrupting device on one end side of the battery units connected in series toward the interrupting device on the other end side so that the current is larger when the interrupting device interrupts the current. A power storage system that has been set up.

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