JPWO2020026499A1 - Storage battery unit and fire detection method for storage battery unit - Google Patents

Abstract

In order to establish a method for quickly and accurately detecting a fire in a storage battery unit from among the devices already in use without adding equipment, the state of the storage battery unit consisting of multiple storage battery cells is monitored and charged / discharged. The control unit that controls has a function of monitoring the temperature state of each of the plurality of storage battery cells and determining the temperature difference between the storage battery cells, and the storage battery cell having a detection temperature equal to or higher than the first threshold value is said to be concerned. The breaker connected in series with the cell is opened, the detected temperature of the cell is compared with the detected temperature of the storage battery cell other than the cell, and the temperature difference between the two is equal to or greater than the second threshold value. , If at least one of the rate at which the detection temperature of the cell rises is equal to or higher than the third threshold value or the maximum value of the detection temperature of the cell is equal to or higher than the fourth threshold value is satisfied, the storage battery It is determined that a fire has been detected in the unit.

Description

The present invention relates to a storage battery unit and a fire detection method for the storage battery unit, and is particularly suitable for a storage battery unit mounted on a railway vehicle.

Railroad vehicles are transportation systems that consume less energy than other transportation systems such as automobiles. On the other hand, there is increasing interest in environmental issues such as global warming, and further energy conservation is required for railway vehicles.

As part of such energy conservation in the field of railway vehicles, energy conservation efforts are being made by applying battery technology.

For example, by mounting a storage battery unit and a main converter on a pneumatic vehicle and using the motor as a generator during brake operation, regenerative braking is performed to recover the kinetic energy of the vehicle as electrical energy, and the power obtained by the regenerative braking is performed. A hybrid pneumatic vehicle has been proposed in which the storage battery unit is charged and used during power driving.

In addition, the main converter that drives the railway vehicle is equipped with a storage battery unit that can charge and discharge electric power, and the storage battery unit absorbs the electric power that cannot be returned to the overhead line during regenerative braking, and the electric power is used during regenerative operation. Absorbents and the like have been studied and put into practical use.

As an example of a storage battery unit for a railroad vehicle, a plurality of battery modules (hereinafter referred to as "modules") equipped with a storage battery cell (hereinafter referred to as "cell") represented by a lithium ion battery and the state of the module are monitored. However, there is a unit having a control unit that controls charging and discharging. A temperature detection element represented by a thermistor is attached to each storage battery cell to constantly monitor the temperature state.

In a railway vehicle equipped with a battery (storage battery), there is a risk that the cell will ignite and a fire will occur if it receives a strong impact. In Patent Document 1, as an operation after detecting a vehicle fire, a fire sensor for detecting a fire and a gas detection sensor for detecting smoke inside the battery unit are used, and these sensors detect a fire or smoke inside the battery unit. If this happens, the necessity of opening / closing the air supply / exhaust port of the battery box housing or charging / discharging operation is determined for the battery unit in consideration of the presence or absence of an emergency operation command, and the main conversion device is stopped / operated. The technique to judge is shown.

Japanese Unexamined Patent Publication No. 2012-129136

In a railway vehicle equipped with a battery (storage battery), there is a risk that the cell will ignite and a fire will occur if it receives a strong impact. From the viewpoint of safety in railway operation, in the event of a fire, it is necessary to promptly notify the crew and stop the vehicle. For that purpose, a method for detecting a fire quickly and accurately is required.

On the other hand, railroad vehicles equipped with batteries (storage batteries) have a much larger number of equipment and systems than ordinary vehicles. Therefore, it is desirable to establish a method for detecting a fire from among the devices already in use without adding new devices.

In order to solve the above problems, the storage battery unit according to the present invention includes a control unit that monitors the state of the storage battery unit composed of a plurality of storage battery cells and controls charging / discharging, and the control unit is the temperature of each of the plurality of storage battery cells. It has a function of monitoring the state and determining the temperature difference between the storage battery cells, and opens the breaker connected in series with the storage battery cells whose detection temperature is equal to or higher than the first threshold value. Then, the detection temperature of the cell is compared with the detection temperature of the storage battery cell other than the cell, and the temperature difference between the two is equal to or larger than the second threshold value, or the detection temperature of the cell rises at a third speed. It is characterized in that it is determined that a fire outbreak of the storage battery unit has been detected if at least one of the threshold value or higher or the maximum value of the detection temperature of the cell is equal to or higher than the fourth threshold value is satisfied. And.

According to the present invention, it is possible to quickly and accurately detect a fire in a storage battery unit by using a temperature detection value from a temperature detector attached to a cell. In addition, since the temperature detector attached to the cell for monitoring the temperature of the cell is also used for fire detection, fire detection can be performed without adding new equipment.

It is a figure which shows the main circuit configuration of the railroad vehicle which carries the storage battery unit which concerns on this invention. It is a figure which shows an example of a DC power supply source. It is a figure which shows the internal structure of a storage battery unit. It is a figure which shows the flowchart from the temperature detection value of the thermistor to the fire detection of a storage battery unit in Example 1. FIG. It is a figure which shows the flowchart from the temperature detection value of the thermistor to the fire detection of a storage battery unit in Example 2. FIG. It is a figure which shows the flowchart from the fire detection which concerns on Examples 1 and 2 to the judgment of a train operation.

Hereinafter, Examples 1 and 2 will be described in detail with reference to FIGS. 1 and 2 as embodiments of the present invention.

The first embodiment will be described with reference to FIGS. 1 to 4 and 6.
FIG. 1 is a diagram showing a main circuit configuration of a railway vehicle equipped with a storage battery unit according to the present invention.
When powering the vehicle, the electric power charged in the storage battery unit (104) is converted into three-phase alternating current by the inverter (102) to power the traction motor (103). When the electric power stored in the storage battery unit (104) is insufficient, the electric power is additionally supplied from the DC power supply source (101) to the inverter (102) and the storage battery unit (104) is charged. When braking the vehicle, the traction motor (103) is operated to generate electricity, converted by the inverter (102), and then charged to the storage battery unit (104).

Further, an auxiliary power supply device (105) is attached between the inverter (102) and the DC power supply source (101) separately from the storage battery unit (104) to generate electric power for interior lighting and air conditioning.

The storage battery unit (104) includes a storage battery unit control unit (106), and can exchange information with each other with the inverter (102) and the cab monitoring device (107). A typical example of the storage battery is a lithium ion battery, but the storage battery is not limited to this.

FIG. 2 is a diagram showing an example of a DC power supply source (101).
The engine (201) is operated to generate AC power by a directly connected generator (202), and this AC power is converted into DC power by a converter (203) and supplied.

FIG. 3 is a diagram showing the internal structure of the storage battery unit (104) shown in FIG.
Since railroad vehicles have larger DC voltage and current values than automobiles, a plurality of cells (311 to 318) are connected in parallel and in series to support high voltage and large current. In the first embodiment, the storage battery unit (104) is first branched into two parallel circuits, and each parallel circuit is composed of a series circuit in which four cells (311 to 314 and 315 to 318) are connected in series. ..

Further, the breakers 1 and 2 (331 and 332) are connected in series to each of the parallel circuits. In the first embodiment, the breakers 1 and 2 (331 and 332) are housed in the storage battery unit (104). However, the breaker may be connected on the circuit between the main converter and each cell, and the physical location where the device is housed does not matter.

Further, one thermistor (321 to 328) is attached to each cell (311 to 318) as a temperature detecting element. Therefore, the element is not limited to the thermistor as long as it has a temperature detection function, but as an example, a case where a thermistor is adopted is used. The thermistor (321-328) constantly detects the temperature of the cell surface and transmits the temperature detection signal to the storage battery unit control unit (106) shown in FIG. Further, it is desirable that the wiring from the tip of the thermistor (321 to 328) to the storage battery unit control unit (106) is covered with an aluminum sheet or the like in order to improve durability against high temperature and flame.

FIG. 4 is a diagram showing a flowchart from the temperature detection value of the thermistor attached to each cell to the detection of a fire in the storage battery unit in the first embodiment. Since the flowchart of fire detection in each cell is common, FIG. 4 shows fire detection for cells 1 to 3 (311 to 313).

In the following, the fire detection in the cell 1 (311) will be taken as an example and will be described in order according to the flowchart. Further, since the main body of the processing is common to the storage battery unit control unit (106), the notation of the main body will be omitted below.

In step 11 (S11), it is determined whether or not the temperature detection value of the thermistor 1 (321) is equal to or higher than the first determination threshold value t1 ° C. If NO, that is, if the temperature detection value of the thermistor 1 (321) is less than the first determination threshold value t1 ° C., the cell 1 (311) is determined to be normal, and the process ends. However, since the process of this step 11 (S11) is an infinite loop, the temperature detection value of the thermistor 1 (321) is updated again every control cycle, and the process is started.

If YES, that is, if the temperature detection value of the thermistor 1 (321) is equal to or higher than the first determination threshold value t1 ° C., in step 12 (S12), the breaker of the series circuit including the cell 1 (311) ( In FIG. 3, the breaker 1 (331)) is opened, and the series circuit including the cell 1 (311) is separated from the main body of the storage battery unit (104) to cut off the current.

Then, in step 13 (S13), it is determined whether or not at least one of the following three conditions i) to iii) is satisfied.
i) The temperature difference between the detected temperature of cell 1 (311) and the detected temperature of cell 8 (318), which is physically farthest from the cell 1 (311), is the second determination threshold value t2 ° C. Whether or not it is the above (in short, the cell selected here is the cell installed at the position physically farthest from the cell to be detected).
ii) Whether or not the speed of temperature rise per unit time of the temperature detection value of thermistor 1 (321) (that is, the detection temperature of cell 1 (311)) is equal to or higher than the third determination threshold value t3 ° C./s.
iii) Whether or not the maximum value of the temperature detection value of the thermistor 1 (321) (that is, the detection temperature of cell 1 (311)) is equal to or higher than the fourth determination threshold value t4 ° C.

If YES (satisfying at least one of the above three conditions), it is detected in step 14 (S14) that a fire has occurred in cell 1 (311). If NO, the breaker 1 (331) remains open and is in a standby state until the process is completed and the storage battery unit control unit (106) resets it.

After the breaker 1 (331) is opened, no current flows through the cell 1 (311). Therefore, if the cause of the temperature rise is an overcurrent, the temperature rise stops and the other cells 2 to 8 (311) ( The temperature difference from 312-318) should be almost eliminated. However, if cell 1 (311) has a fire, it is expected that the temperature difference from other cells 2 to 8 (312 to 318) will widen even if the current is cut off.

Since the railroad vehicle has a plurality of cells in the storage battery unit, the physical distance from the farthest (that is, the farthest) cell is large. Therefore, it is unlikely that the temperature of the cell at the farthest position (cell 8 corresponds to cell 1) rises due to the cell that caused the fire, and the temperature difference between the two cells is the second. The fire detection of the target cell can be performed by determining whether or not the determination threshold value is t2 ° C. or higher.

However, it cannot be denied that the cell at the farthest position may also have a fire at the same time. Therefore, in order to cope with such a situation and improve the reliability of fire detection, the speed of temperature rise of the target cell should be equal to or higher than the third determination threshold value t3 ° C./s as described in ii) and iii) above. Alternatively, the fact that the maximum detection temperature of the target cell is equal to or higher than the fourth determination threshold value t4 ° C. is also incorporated into the conditions for fire detection, and if at least one of the above three conditions is satisfied, it is detected as a fire. I will try to deal with it.

FIG. 4 shows the process from the temperature detection value of the thermistor to the determination of the fire detection of the cell for cells 1 (311) to 3 (313), but the remaining cells 4 (314) to 8 (318). ) Is the same. As a result, when at least one or more of cells 1 (311) to 8 (318) are finally determined to be cell fire detection in step 15 (S15), it is determined to be fire detection of the storage battery unit (104). To.

FIG. 6 is a diagram showing a flowchart from fire detection of the storage battery unit to determination of train operation. This flowchart is common to the first embodiment and the second embodiment described later.
In step 16 (S16), the storage battery unit control unit (106) determines the presence or absence of fire detection in the storage battery unit (104), and if the fire detection in the storage battery unit (104) is determined (YES), step 17 (YES). In S17), the fire detection information is transmitted to the cab monitoring device (107). On the other hand, if the determination is not made (NO), since the process of this step 17 (S17) is an infinite loop, the fire detection determination is repeated every control cycle.

Next, in step 18 (S18), from the information of the vehicle information control device (not shown), the current position of the train is a train stop danger section such as an underground section, a tunnel section or a bridge section, a densely populated area or passengers. It is determined whether or not the train falls under an inappropriate stop section for stopping a train that has caused a fire, such as a stop avoidance section such as a station where the train is located. This determination may be made by the vehicle driving control device (not shown) that receives the vehicle position information from the cab monitor device (107) and the vehicle information control device (not shown), or the fire detection information and the vehicle. A crew member such as a driver may perform the operation by looking at the cab monitoring device (107) that receives (displays) vehicle position information from the information control device (not shown).

If YES, in step 19 (S19), the storage battery unit (104) is released from the main circuit, and DC power is supplied until it reaches the outside of the stop section that is inappropriate for stopping the train that caused the fire. Using the source (101), the train continues to run and returns to step 18 (S18). The process of step 19 (S19) may also be performed by the vehicle driving control device (not shown), or may be manually performed by a crew member such as a driver.

If NO, in step 20 (S20), the storage battery unit (104) is released from the main circuit, the inverter (102) is promptly stopped, and a train stop command is issued. This process may also be performed by the vehicle driving control device (not shown), or may be manually performed by a crew member such as a driver.

The second embodiment will be described with reference to FIG. In the second embodiment, the conditions for detecting the fire in the cell are different from those in the first embodiment, but the other operation modes are the same and are omitted. The apparatus configuration is the same as that of the first embodiment shown in FIGS. 1 to 3.

FIG. 5 is a diagram showing a flowchart from the temperature detection value of the thermistor attached to each cell to the detection of a fire in the storage battery unit in the second embodiment. As in the first embodiment, cell 1 (311) will be taken as an example for description. Further, since the main body of the processing is common to the storage battery unit control unit (106), the notation of the main body will be omitted below.

In step 11 (S11) and step 12 (S12), the second embodiment has the same processing mode as that of the first embodiment. Simply, the temperature detection value of the thermistor 1 (321) is equal to or higher than the first determination threshold value t1 ° C. Whether or not (S11) is determined, and if YES, the breaker 1 (331) of the series circuit of the storage battery unit (104) including the cell 1 (311) is opened, and the series circuit including the cell 1 (311) is opened. The current is cut off by disconnecting from the main circuit (S12).

Then, in step 23 (S23), it is determined whether or not at least one of the following three conditions iv), ii) and iii) is satisfied.
iv) When the temperature difference between the detected temperature of cell 1 (311) and the average value of the detected temperatures of cells 2 to 8 (312 to 318) other than cell 1 (311) is the fifth determination threshold value t5 ° C. or higher. Whether or not there is
ii) Whether or not the speed of temperature rise per unit time of the temperature detection value of thermistor 1 (321) (that is, the detection temperature of cell 1 (311)) is equal to or higher than the third determination threshold value t3 ° C./s.
iii) Whether or not the maximum value of the temperature detection value of the thermistor 1 (321) (that is, the detection temperature of cell 1 (311)) is equal to or higher than the fourth determination threshold value t4 ° C.

If YES, it is detected in step 14 (S14) that a fire has occurred in cell 1 (311), as in the first embodiment.

As described above, in the first embodiment, the detection temperature of the cell 1 (311) and the cell 8 (318 with respect to the cell 1 (311)) which is physically farthest from the cell 1 (311). )) Was determined whether or not the temperature difference from the detected temperature was equal to or higher than the second determination threshold value t2 ° C., but in Example 2, the detected temperature of cell 1 (311) and other than cell 1 (311) were determined. The difference is that it is determined whether or not the temperature difference from the average value of each detected temperature in cells 2 to 8 (312 to 318) is equal to or higher than the fifth determination threshold value t5 ° C.

In the second embodiment, when a fire broke out in cell 1 (311), it happened to be in the cell at the physically farthest position (cell 8 (318) with respect to cell 1 (311)). Even if a fire has occurred, the fire can be detected by comparing the detected temperature of cell 1 (311) with the average value of each detected temperature of all the remaining cells other than cell 1 (311). ..

However, if a fire breaks out in cell 1 (311), the temperature of the cells around cell 1 (311) is also considered to rise. Therefore, the fifth determination threshold value t5 ° C. adopted in Example 2 is the fifth. Set to a value larger than the determination threshold value t2 ° C. of 2. In any case, as in the first embodiment, the speed of temperature rise of the target cell itself is equal to or higher than the third determination threshold value t3 ° C./s, or the maximum value of the detected temperature of the target cell is the fourth determination threshold value. The fact that the temperature is t4 ° C. or higher is also intended to improve the reliability of fire detection by incorporating it into the conditions for fire detection.

101: DC power supply source, 102: Inverter, 103: Traction motor,
104: Storage battery unit, 105: Auxiliary power supply, 106: Storage battery unit control unit,
107: Driver's cab monitoring device, 201: Engine, 202: Generator, 203: Converter,
311: Battery cell 1, 312: Battery cell 2, 313: Battery cell 3,
314: Storage battery cell 4, 315: Storage battery cell 5, 316: Storage battery cell 6,
317: Battery cell 7, 318: Battery cell 8, 321: Thermistor 1,
322: Thermistor 2, 323: Thermistor 3, 324: Thermistor 4,
325: Thermistor 5, 326: Thermistor 6, 327: Thermistor 7,
328: Thermistor 8, 331: Breaker 1, 332: Breaker 2

Claims (9)

A storage battery unit equipped with multiple storage battery cells.
It is equipped with a control unit that monitors the status of the storage battery unit and controls charging and discharging.
The control unit is a storage battery unit having a function of monitoring the temperature state of each of the plurality of storage battery cells and determining the temperature difference between the storage battery cells. The storage battery unit according to claim 1.
When at least one of the temperature detection signals from each of the temperature detection elements attached to each of the plurality of storage battery cells reaches a detection temperature equal to or higher than the first threshold value, the control unit reaches the detection temperature equal to or higher than the first threshold value. A storage battery unit characterized by opening a breaker connected in series with the storage battery cell. The storage battery unit according to claim 2.
The control unit uses the storage battery cell whose detection temperature is equal to or higher than the first threshold value as a target cell.
(1) The detection temperature of the target cell is compared with the detection temperature of the storage battery cell other than the target cell, and the temperature difference between the two is equal to or greater than the second threshold value. (2) The rate of increase of the detection temperature of the target cell. Is equal to or greater than the third threshold value. (3) The maximum value of the detection temperature of the target cell is equal to or greater than the fourth threshold value. A storage battery unit characterized in that it is determined that a fire has been detected in the storage battery unit. The storage battery unit according to claim 3.
The storage battery unit according to (1), other than the target cell, is the storage battery cell at a position physically farthest from the target cell in the storage battery unit. The storage battery unit according to claim 2.
The control unit uses the storage battery cell whose detection temperature is equal to or higher than the first threshold value as a target cell.
(1) The detection temperature of the target cell is compared with the average value obtained from the detection temperatures of all the storage battery cells other than the target cell, and the temperature difference between the two is equal to or greater than the fifth threshold value. (2) The target The rate of increase in the detection temperature of the cell is equal to or higher than the third threshold value (3) The maximum value of the detection temperature of the target cell is equal to or higher than the fourth threshold value. A storage battery unit characterized in that it is determined that a fire has been detected in the storage battery unit if one of the above conditions is satisfied. The storage battery unit according to any one of claims 3 to 5.
When the control unit determines that a fire has occurred in the storage battery unit, the control unit transmits information regarding the fire to the monitoring device. The storage battery unit according to any one of claims 3 to 6, which is mounted on a railroad vehicle.
When the control unit determines that a fire has occurred in the storage battery unit, it determines whether or not the current position of the railcar is an inappropriate section for stopping, and if it is an inappropriate section, the relevant section. The storage battery unit is released from the main circuit, a command is issued to run the railroad vehicle until it passes through the inappropriate section and stop using another power supply source, and if it is not the inappropriate section, the storage battery unit is not used. A storage battery unit for rolling stock, which is characterized by issuing a command to stop the rolling stock by releasing the main circuit. A railway vehicle equipped with the storage battery unit according to any one of claims 1 to 7. It is a fire detection method for a storage battery unit equipped with multiple storage battery cells.
The detection temperature of the target cell is compared with the detection temperature of the storage battery cell other than the target cell, with at least one storage battery cell having a detection temperature equal to or higher than the first threshold value among the plurality of storage battery cells as the target cell. , The first step of determining whether the temperature difference between the two is greater than or equal to the second threshold.
A second method of comparing the detected temperature of the target cell with the average value obtained from the detected temperatures of all the storage battery cells other than the target cell, and determining whether or not the temperature difference between the two is equal to or greater than the fifth threshold value. Steps and
A third step of determining whether or not the rate of increase in the detection temperature of the target cell is equal to or higher than the third threshold value, and
The fourth step of determining whether or not the maximum value of the detected temperature of the target cell is equal to or higher than the fourth threshold value, and
A fire detection method for a storage battery unit, comprising a fifth step of determining that a fire has been detected in the storage battery unit if at least one of the first to fourth steps is satisfied.

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