JP7484615B2 - Vehicle battery state detection method and detection control device - Google Patents

Description

The present invention relates to a method for detecting the state of a vehicle battery and a detection control device.

To prevent batteries installed in vehicles from catching fire, it is necessary to prevent thermal runaway caused by an increase in temperature due to an abnormal battery reaction, or damage caused by an increase in internal pressure due to gas generation. To do this, it is desirable to monitor both the temperature and strain of the battery. Temperature increases can be detected by thermocouples, and strain (increase in internal pressure) can be detected by pressure sensors. However, doing both of these things would result in extremely complicated electrical wiring, etc.

In response to this, it is known to use optical fiber to measure temperature and strain. This is a measurement technique that utilizes the fact that a detection unit (sensor) that generates reflected light of a Brad wavelength in response to incident light is provided in the optical fiber, and that the Brad wavelength changes according to the temperature and strain of the detection unit. However, since the wavelength changes due to both a temperature change and the occurrence of strain, it is not possible to distinguish which is the source of the wavelength change.

Patent document 1 describes a method of determining the temperature-compensated strain of a battery by providing a first optical sensor that detects strain within an optical fiber and a second optical sensor that detects temperature without being affected by strain, and correcting the value of the first optical sensor with the temperature value obtained from the second optical sensor.

JP 2015-198085 A

In the case of the method described in Patent Document 1, in order to obtain temperature compensation strain, it is necessary to provide an optical sensor for temperature compensation in one optical fiber separately from an optical sensor for strain detection. Also, since the temperatures at the locations on the battery where the two optical sensors are placed are not necessarily the same, it cannot necessarily be said that strain can be detected with high accuracy.

The objective of the present invention is to detect the temperature and strain of a battery with high accuracy without providing a compensation optical sensor in the optical fiber.

To solve the above problem, the present invention determines the temperature compensation strain of the detection site based on the outside air temperature and the wavelength of the reflected light when there is no change in the battery temperature, and determines the strain compensation temperature of the detection site from the temperature compensation strain and the wavelength of the reflected light when there is a change in temperature. The details are explained below.

The method for detecting the state of a vehicle battery disclosed herein is a method for detecting the temperature and distortion of a battery cell mounted on a vehicle, comprising the steps of:
an optical sensor that reflects incident light and whose wavelength changes in response to changes in shape and temperature, said optical sensor being fixed to an optical fiber at a detection portion of the battery cell where the temperature and distortion of the battery cell are to be detected;
A wavelength measuring device for measuring the wavelength;
An outside air temperature sensor for measuring an outside air temperature of the vehicle,
measuring the wavelength and the outside air temperature when the vehicle is parked and not using the battery cell;
determining a temperature compensation strain of the detection portion based on the wavelength and the outside air temperature measured during parking;
measuring the wavelength of the reflected light by the wavelength measuring device when the battery cell is in use;
The method further comprises a step of determining a strain-compensated temperature of the detection portion based on the wavelength and the temperature-compensated strain measured during use of the battery cell.

The present disclosure also provides a vehicle battery state detection control device that detects the temperature and distortion of a battery cell mounted in a vehicle, comprising:
an optical sensor that reflects incident light and whose wavelength changes in response to changes in shape and temperature, said optical sensor being fixed to an optical fiber at a detection portion of the battery cell where the temperature and distortion of the battery cell are to be detected;
a light source for injecting light into the optical fiber;
A wavelength measuring device for measuring the wavelength;
An outside air temperature sensor for measuring an outside air temperature of the vehicle;
a calculation device that calculates the temperature and strain of the detection site based on the wavelength and the outside air temperature,
The calculation device acquires the wavelength measured by the wavelength measuring device and the outside air temperature measured by the outside air temperature sensor when the vehicle is parked and the battery cell is not being used, and calculates a temperature compensation distortion of the detection location based on the wavelength and the outside air temperature, and acquires the wavelength measured by the wavelength measuring device when the battery cell is in use, and calculates a distortion compensation temperature of the detection location based on the wavelength and the temperature compensation distortion.

Both the detection method and the detection control device described above are based on the premise that the battery cell is not in use (no charging or discharging) when the vehicle is parked, so there is no temperature change at the detection location of the battery cell, and the outside air temperature measured by the outside air temperature sensor can be regarded as the temperature of the detection location. It is preferable to measure the wavelength several hours (e.g., 2 or 3 hours) after charging or discharging of the battery cell has stopped. After such a time has passed, the temperature of the battery cell will usually be the same as the outside air temperature.

The wavelength of the reflected light obtained when the vehicle is parked reflects the effects of distortion and temperature at the detection site of the battery cell. The detection method and detection control device obtain temperature information from an outside air temperature sensor to determine the temperature compensation distortion at the detection site. In short, the temperature influence appearing in the wavelength of the reflected light is corrected with the outside air temperature to determine the temperature compensation distortion.

On the other hand, the wavelength of the reflected light obtained when the battery cell is in use is also affected by the distortion and temperature of the detection site. The detection method and detection control device employ the previously determined temperature compensation distortion as distortion information for determining the distortion compensation temperature of the detection site. In short, the distortion-influenced portion of the wavelength of the reflected light is corrected with the temperature compensation distortion to determine the distortion compensation temperature.

In this way, with the above detection method and detection control device, temperature information for determining the temperature compensation distortion is obtained from the outside air temperature when the vehicle is parked, and the above temperature compensation distortion is used as distortion information for obtaining the distortion compensation temperature, so that the temperature and distortion of the battery cell can be detected with high accuracy without providing a separate optical sensor for compensation in the optical fiber.

In one embodiment of the detection method and detection control device, temperature dependency data of the wavelength of the reflected light by the optical sensor is provided, and the temperature corresponding to the wavelength measured while the vehicle is parked is calculated based on the temperature dependency data, and the temperature compensation distortion is calculated from the wavelength shift amount corresponding to the temperature difference between the temperature and the outside air temperature measured while the vehicle is parked.

In other words, the wavelength shift equivalent to the difference between the temperature measured by the optical sensor and the temperature measured by the outside air temperature sensor is converted into strain. This makes it possible to accurately determine the temperature compensation strain of the detection area of the battery cell.

In one embodiment of the detection method, after the optical sensor is fixed to the detection portion of the battery cell, the wavelength and the outside air temperature are measured before the first use of the battery cell is started, the temperature corresponding to the wavelength is obtained based on the temperature dependency data, and the temperature dependency data is corrected so that the temperature corresponds to the outside air temperature, and the temperature compensation distortion is calculated using the corrected temperature dependency data.

When an optical fiber sensor is attached to the detection site of a battery cell, if the optical sensor is not distorted, the temperature obtained from the wavelength of the reflected light based on the temperature dependency data is expected to match the outside air temperature. If this match is not observed, it can be assumed that a load is applied when the optical sensor is attached, causing distortion.

Therefore, after the optical sensor is fixed to the detection portion, and before the first use of the battery cell is started, the temperature corresponding to the above wavelength is found based on the temperature-dependent data, and the temperature-dependent data is corrected so that this temperature matches the above-mentioned outside air temperature. In other words, the temperature value of the temperature-dependent data is corrected by the amount of mounting distortion occurring in the optical sensor. This makes it possible to accurately find the temperature compensation distortion.

In one embodiment of the detection method and detection control device, a wavelength shift amount corresponding to the previous value of the temperature compensation strain is subtracted from the wavelength detected when the battery cell is in use, and the strain compensation temperature is calculated from the wavelength after this subtraction based on the temperature dependency data.

In other words, the wavelength of the reflected light is corrected with the wavelength shift of the previously calculated temperature compensation strain to determine the temperature. This makes it possible to accurately determine the strain compensation temperature of the detection site of the battery cell.

In one embodiment of the detection method and the detection control device,
The battery cell is a hexahedral rectangular cell,
a coolant passage for cooling the battery cell extending along at least one of six faces of the battery cell;
The detection sites are provided in a central region of the widest of the six faces of the battery cell and in a region farther from the refrigerant passage than the central region, and the optical sensors are provided at these detection sites.

The central region of the widest surface of a hexahedral battery cell is the area that is likely to become distorted when the internal pressure of the battery cell rises. In addition, the area of the battery cell that is far from the refrigerant passage is the area that is likely to become hot when the temperature inside the cell rises due to an abnormality in the battery reaction, etc. According to the above embodiment, optical sensors are arranged at detection sites in both of these areas, so that the temperature rise and distortion of the battery cell can be detected early and countermeasures can be taken.

In one embodiment of the detection method and the detection control device,
two coolant passages for cooling the battery cells extending along the opposing faces of the battery cells,
The optical fiber has a portion arranged on a surface extending from one side of both refrigerant passages of the battery cell to the other side of the both refrigerant passages, and a plurality of the optical sensors are provided at intervals in this portion.

This makes it possible to grasp the temperature distribution occurring in the battery cell between the opposing refrigerant passages. This makes it easy to control the temperature of the battery cell to a target temperature by adjusting the refrigerant flow rate in both refrigerant passages, or to prevent localized temperature unevenness.

According to the present invention, the temperature information for determining the temperature compensation strain is obtained from the outside air temperature when the vehicle is parked, and the above-mentioned temperature compensation strain is used as the strain information for obtaining the strain compensation temperature. This makes it easy to detect the temperature and strain of the battery cell with high accuracy without providing a separate optical sensor for compensation in the optical fiber.

FIG. 2 is a perspective view of a vehicle battery state detection control device. FIG. 11 is a graph showing an example of temperature dependency data of the wavelength of reflected light. FIG. 11 is a graph showing an example of data showing the relationship between the distortion of a battery cell and the wavelength shift. FIG. 4 is a flow diagram of a temperature compensation distortion calculation process. FIG. 4 is a flow diagram of a distortion compensation temperature calculation process.

The following describes the embodiments of the present invention with reference to the drawings. The following description of the preferred embodiment is merely exemplary in nature and is not intended to limit the present invention, its applications, or its uses.

In the vehicle battery state detection control device shown in Figure 1, 1 is a chargeable and dischargeable battery cell mounted on the vehicle, which in this embodiment is a hexahedral rectangular cell. The vehicle is mounted with multiple battery cells 1 as a battery module in which the front surface 1a and rear surface 1b, which have the largest surface area, are arranged side by side facing each other. In this battery module, the multiple battery cells 1 are connected in series. The vehicle is a parallel type hybrid vehicle. The battery cells 1 are used to supply power to the motor that drives the vehicle, and to store the kinetic energy generated when the vehicle is braked as electrical energy.

The battery module is provided with an upper refrigerant passage 2 and a lower refrigerant passage 3 that extend in the direction in which the battery cells 1 are arranged along the upper surface 1c and the lower surface 1d of the battery cells 1, which are opposed to each other. A refrigerant (cooling water) flows through both refrigerant passages 2 and 3, and this refrigerant cools the battery cells 1 from above and below. The refrigerant, whose temperature rises due to cooling the battery cells 1, is cooled by heat exchange with the outside air via a heat exchanger.

A single optical fiber 4 having multiple optical sensors 6 for detecting the temperature and distortion of each battery cell 1 is attached to the multiple battery cells 1. One end of the optical fiber 4 is connected to a light source (wavelength swept light source) 5 that inputs light to the optical fiber 4. The optical sensor 6 is an FBG (fiber Bragg grating) sensor in which a diffraction grating is engraved into the optical fiber 4, and reflects light of a Bragg wavelength, which is a specific wavelength component proportional to the spacing of the diffraction grating, in response to the incident light from the light source 5.

<Installation of optical fiber>
In this embodiment, the optical fiber 4 is attached to the front surface 1a (or the rear surface 1b), which is the surface of each battery cell 1 with the largest area extending from one side to the other side of the refrigerant passages 2, 3. On the front surface 1a of each battery cell 1, the optical fiber 4 extends in a zigzag manner (in the shape of a sine curve) from one side edge of the front surface 1a to the other side edge, going back and forth between one side and the other side of the refrigerant passages 2, 3.

The optical fiber 4 also extends in a zigzag pattern from the other side edge of one battery cell 1 to the other side edge of the front surface 1a of the adjacent battery cell 1, and from the other side edge of the front surface 1a to one side edge. The optical fiber 4 also extends in a zigzag pattern from one side edge of the front surface 1a of the adjacent battery cell 1 to one side edge of the front surface 1a of the next adjacent battery cell 1, and from one side edge of the front surface 1a to the other side edge. By repeating this zigzag arrangement pattern, one optical fiber 4 is provided in a zigzag pattern on the front surfaces 1a of all the battery cells 1 in the battery module.

As a result of the zigzag arrangement, the optical fiber 4 has a portion on the front surface 1a of each battery cell 1 that extends from one side of the refrigerant passages 2, 3 to the other side. A number of optical sensors 6 are provided at intervals on this portion. In other words, a number of detection sites 7 for detecting the temperature and distortion are provided at intervals on the front surface 1a of each battery cell 1 from one side of the refrigerant passages 2, 3 to the other side, and an optical sensor 6 is fixed to each of the detection sites 7.

In addition, detection sites 7 are provided in the central region C of the front surface 1a of the battery cell 1 and in a region F that is farther from the refrigerant passages 2 and 3 than the central region C, and optical sensors 6 are fixed to these detection sites 7.

<Means for measuring Bragg wavelength and ambient temperature>
The Bragg wavelength of the light reflected by the optical sensor 6 changes according to the temperature and distortion of the optical sensor 6. In other words, when an external force is applied to the optical sensor 6 or the temperature changes, the spacing of the diffraction grating changes, and as a result, the Bragg wavelength changes. Therefore, by observing this change in the Bragg wavelength, it is possible to detect the temperature and distortion of the detection portion 7 of the battery cell 1 where the optical sensor 6 is fixed.

To measure the Bragg wavelength, a wavelength measuring device (photoreceiver) 11 is connected midway between the light source 5 and the optical sensor 6 closest to the light source 5 via an optical fiber 12 and an optical circulator 13. The wavelength measuring device 11 and an outside air temperature sensor 15 are connected to a calculation device 14. The outside air temperature sensor 15 is installed in the vehicle and measures the outside air temperature of the vehicle. The calculation device 14 calculates the temperature and strain of each detection site 7 of each battery cell 1 based on the Bragg wavelength obtained from each optical sensor 6 and the outside air temperature obtained from the outside air temperature sensor 15.

In this embodiment, a wavelength multiplexing method is used to observe the reflection spectra of multiple optical sensors 6 with one wavelength measuring device 11. That is, the multiple optical sensors 6 are formed so that their Bragg wavelengths do not overlap even if they shift due to temperature changes and distortion. Note that instead of the wavelength multiplexing method, a time multiplexing method or a frequency multiplexing method can also be used. In this case, the Bragg wavelengths of the multiple optical sensors 6 may be the same.

<Calculation device>
The arithmetic unit 14 includes a microcomputer and a memory (e.g., an EEPROM, a flash memory). The memory includes temperature dependency data (wavelength-temperature map) of the Bragg wavelength shown in FIG. 2 and data on the shift of the Bragg wavelength due to distortion (wavelength shift-distortion map) shown in FIG. 3. The wavelength-temperature map is a map in which the relationship between the Bragg wavelength and the temperature change of the optical sensor 6 is experimentally determined in advance and stored electronically, since the Bragg wavelength changes in response to the temperature change of the optical sensor 6. The wavelength shift-distortion map is a map in which the relationship between the Bragg wavelength and the temperature change of the optical sensor 6 is experimentally determined in advance and stored electronically, since the Bragg wavelength shifts in response to the distortion of the optical sensor 6.

The calculation device 14 performs the correction process of the wavelength-temperature map, and the calculation process of the temperature compensation strain ε and the strain compensation temperature T1 of each detection site 7 based on the Bragg wavelength measured by the wavelength measuring device 11 and the outside air temperature measured by the outside air temperature sensor 15. The calculation process of the temperature compensation strain ε and the strain compensation temperature T1 will be explained first.

(Calculation of temperature compensation strain ε)
When the vehicle is parked and not in use with the battery cells 1, the calculation device 14 acquires the Bragg wavelength λ' measured by each optical sensor 6 using the wavelength measurement device 11 and the outside air temperature T of the vehicle measured by the outside air temperature sensor 15. However, the Bragg wavelength λ' and the outside air temperature T are measured after a predetermined time (three hours in this embodiment) has elapsed since the start of parking, during which the temperature of the battery cells 1 becomes equal to the outside air temperature.

The computing device 14 derives the wavelength-corresponding temperature T' from the wavelength-temperature map (Figure 2) based on the measured Bragg wavelength. The computing device 14 derives the wavelength shift Δλ corresponding to the temperature difference ΔT from the wavelength-temperature map, and derives the temperature-compensated strain ε of each detection site 7 from the wavelength shift-strain map (Figure 3) based on this wavelength shift Δλ.

(Calculation of strain compensation temperature T1)
The computing device 14 calculates the strain compensation temperature T1 while the vehicle is running using the battery cell 1. First, a wavelength shift Δλ1 corresponding to the strain ε1 is derived from the wavelength shift-strain map (FIG. 3) based on the previous value ε1 of the temperature compensation strain ε at each detection site 7. The wavelength shift Δλ1 is subtracted from the blood wavelength λ2 obtained by the optical sensor 6 at each detection site 7, and the strain compensation temperature T1 at each detection site 7 is derived from the wavelength-temperature map (FIG. 2) based on the wavelength λ3 corrected by the subtraction.

(Correction of wavelength-temperature map)
When the optical sensor 6 is fixed to the detection site 7 of the battery cell 1, a load may be placed on the optical sensor 6, causing distortion. In that case, the distortion will be reflected in the measurement value obtained by the wavelength measurement device 11, causing an error of the amount of the distortion to occur in the temperature-compensated strain ε and strain-compensated temperature T1 obtained by the calculation device 14.

Therefore, after the optical sensor 6 is fixed to the detection site 7 of the battery cell 1, before the first use of the battery cell 1 is started (in a parked state where the temperature of the battery cell 1 can be considered to be equal to the outside air temperature), the blood wavelength and outside air temperature are measured by the optical sensor 6 for each detection site 7. Then, based on the blood wavelength, the wavelength-corresponding temperature is derived from the wavelength-temperature map (Figure 2). If there is an optical sensor 6 for which there is a temperature difference between this wavelength-corresponding temperature and the outside air temperature, a correction is made to the wavelength-temperature map of that optical sensor 6 by changing the temperature by the temperature difference so that the wavelength-corresponding temperature matches the outside air temperature. This corrected wavelength-temperature map is used to detect the temperature compensation strain ε and the strain compensation temperature T1.

(Flow of calculation process of temperature compensation strain and strain compensation temperature)
FIG. 4 shows the flow of the temperature compensation distortion calculation process by the calculation device 14. In step S1 after the start, it is determined whether the parking time of the vehicle has exceeded three hours. If the parking time exceeds three hours, the process proceeds to step S2, where outside air temperature information (outside air temperature T) is obtained from the outside air temperature sensor 15. In the following step S3, the blood wavelength λ' reflected by the optical sensor 6 of each detection site 7 is measured and obtained by the wavelength measuring device 11. In the following step S4, the wavelength-corresponding temperature T' is derived from the wavelength-temperature map (FIG. 2) based on the blood wavelength λ'. In the following step S5, the wavelength shift Δλ is derived from the wavelength-temperature map (FIG. 2) based on the temperature difference ΔT (=T'-T) between the wavelength-corresponding temperature T' and the outside air temperature T. In the following step S6, the temperature compensation distortion ε of each detection site 7 is derived from the wavelength shift-distortion map (FIG. 3) based on the wavelength shift Δλ.

Figure 5 shows the flow of the strain compensation temperature calculation process by the calculation device 14. In step S1 after starting, it is determined whether the vehicle is running (battery cell 1 is in use) or not. If the vehicle is running, proceed to step S2, and the temperature compensation strain (previous value of temperature compensation strain) ε1 of each detection site 7 detected most recently is read. In the following step S3, the wavelength shift Δλ1 is derived from the wavelength shift-strain map (Figure 3) based on the temperature compensation strain ε1. In the following step S4, the blood wavelength λ2 reflected by the optical sensor 6 of each detection site 7 is measured and obtained by the wavelength measuring device 11. In the following step S5, the wavelength shift Δλ1 is subtracted from the blood wavelength λ2 to obtain the corrected wavelength λ3. In the following step S6, the strain compensation temperature T1 of each detection site 7 is derived from the wavelength-temperature map (Figure 2) based on the corrected wavelength λ3.

According to the above embodiment, the temperature information for determining the temperature compensation strain at the detection site 7 of the battery cell 1 is obtained from the ambient temperature sensor 15, so there is no need to provide an optical sensor for temperature compensation in the optical fiber 4. Therefore, the detection accuracy of the temperature compensation strain is not affected by the performance of the optical sensor for temperature compensation, and the temperature compensation strain can be detected stably and accurately. In addition, in detecting the strain compensation temperature, the previous value of the temperature compensation strain is used as the strain information, so the strain compensation temperature can be detected stably and accurately.

In addition, according to the above embodiment, after the optical sensor 6 is fixed to the detection site 7 of the battery cell 1, the blood wavelength and the outside air temperature are measured before the first use of the battery cell 1 is started, and the wavelength-temperature map is corrected so that the wavelength-corresponding temperature matches the outside air temperature. Therefore, even if the optical sensor 6 has an installation distortion, the temperature compensation distortion and the distortion compensation temperature can be detected with high accuracy.

In addition, according to the above embodiment, detection sites 7 are provided in the central region C (region where distortion is likely to occur) of the widest surface 1a of the battery cell 1 and in the region F far from the refrigerant passages 2 and 3 (region where high temperatures tend to occur) to detect temperature-compensated distortion and distortion-compensated temperature. Therefore, it is possible to detect the temperature rise and distortion of the battery cell 1 early on and take measures (increasing cooling of the battery cell 1, stopping use of the battery cell 1, etc.).

In addition, according to the above embodiment, on the surface 1a extending from one side to the other side of the refrigerant passages 2, 3, a plurality of detection sites 7 are provided at intervals from one side to the other side to detect temperature compensation strain and strain compensation temperature. Therefore, it becomes possible to grasp the type of temperature distribution occurring in the battery cell 1 between the opposing refrigerant passages 2, 3. Therefore, by adjusting the refrigerant flow rate in both refrigerant passages 2, 3, it becomes easy to control the temperature of the battery cell 1 to a target temperature or prevent local temperature unevenness from occurring.

In FIG. 1, three detection points 7 are provided at intervals from one side of the refrigerant passages 2 and 3 to the other side, but this is just one example. Furthermore, multiple detection points 7 can be provided at short intervals, which allows the temperature distribution of the battery cells 1 to be grasped more precisely.

REFERENCE SIGNS LIST 1 Battery cell 2 Coolant passage 3 Coolant passage 4 Optical fiber 5 Light source 6 Optical sensor 7 Detection part 11 Wavelength measuring device 14 Calculation device 15 Outside air temperature sensor

Claims (11)

A method for detecting the state of a vehicle battery, comprising the steps of: detecting a temperature and a distortion of a battery cell mounted on a vehicle,
an optical sensor that reflects incident light and whose wavelength changes in response to changes in shape and temperature, said optical sensor being fixed to an optical fiber at a detection portion of the battery cell where the temperature and distortion of the battery cell are to be detected;
A wavelength measuring device for measuring the wavelength;
An outside air temperature sensor for measuring an outside air temperature of the vehicle,
measuring the wavelength and the outside air temperature when the vehicle is parked and not using the battery cell;
determining a temperature compensation strain of the detection portion based on the wavelength and the outside air temperature measured during parking;
measuring a wavelength of the reflected light by the wavelength measuring device when the battery cell is in use;
a step of determining a strain-compensated temperature of the detection portion based on the wavelength and the temperature-compensated strain measured during use. In claim 1,
Data on the temperature dependence of wavelength of reflected light by the optical sensor is provided;
A method for detecting the state of a vehicle battery, characterized in that in the step of calculating the temperature compensation distortion, a temperature corresponding to the wavelength measured while the vehicle is parked is calculated based on the temperature dependence data, and the temperature compensation distortion is calculated from an amount of wavelength shift corresponding to a temperature difference between the calculated temperature and the outside air temperature measured while the vehicle is parked. In claim 2,
a data correction step of measuring the wavelength and the outside air temperature after the optical sensor is fixed to the detection portion of the battery cell and before the first use of the battery cell is started, determining the temperature corresponding to the wavelength based on the temperature dependence data, and correcting the temperature dependence data so that this temperature coincides with the outside air temperature, and determining the temperature compensation distortion using the corrected temperature dependence data. In claim 2 or 3,
A method for detecting the state of a vehicle battery, characterized in that in the step of calculating the distortion compensation temperature, a wavelength shift amount corresponding to a previous value of the temperature compensation distortion is subtracted from the wavelength detected when the battery cell is in use, and the distortion compensation temperature is calculated from the wavelength after subtraction based on the temperature dependence data. In any one of claims 1 to 4,
The battery cell is a hexahedral rectangular cell,
a coolant passage for cooling the battery cell extending along at least one of six faces of the battery cell;
a detection portion provided in a central region of the widest of the six faces of the battery cell and in a region farther from the refrigerant passage than the central region, and the optical sensor is provided at these detection portions. In any one of claims 1 to 5,
two coolant passages for cooling the battery cells extending along the opposing faces of the battery cells,
the optical fiber has a portion arranged to extend from one side of both refrigerant passages of the battery cell to the other side on a surface that extends from one side of both refrigerant passages of the battery cell to the other side, and a plurality of the optical sensors are provided at intervals on this portion. A vehicle battery state detection control device that detects the temperature and distortion of a battery cell mounted on a vehicle,
an optical sensor that reflects incident light and whose wavelength changes in response to changes in shape and temperature, said optical sensor being fixed to an optical fiber at a detection portion of the battery cell where the temperature and distortion of the battery cell are to be detected;
a light source for injecting light into the optical fiber;
A wavelength measuring device for measuring the wavelength;
An outside air temperature sensor for measuring an outside air temperature of the vehicle;
a calculation device that calculates the temperature and strain of the detection site based on the wavelength and the outside air temperature,
The vehicle battery state detection control device is characterized in that the calculation device acquires the wavelength measured by the wavelength measuring device and the outside air temperature measured by the outside air temperature sensor when the vehicle is parked and the battery cell is not in use, and determines the temperature compensation distortion of the detection location based on the wavelength and the outside air temperature, and acquires the wavelength measured by the wavelength measuring device when the battery cell is in use, and determines the distortion compensation temperature of the detection location based on the wavelength and the temperature compensation distortion. In claim 7,
The computing device has temperature dependency data of the wavelength of the reflected light by the optical sensor, calculates a temperature corresponding to the wavelength measured while the vehicle is parked based on the temperature dependency data, and calculates the temperature compensation distortion from an amount of wavelength shift corresponding to the temperature difference between that temperature and the outside air temperature measured while the vehicle is parked. In claim 8,
The computing device subtracts a wavelength shift amount corresponding to a previous value of the temperature compensation distortion from the wavelength measured during use of the battery cell, and calculates a distortion compensation temperature from the wavelength after subtraction based on the temperature dependence data. In any one of claims 7 to 9,
The battery cell is a hexahedral rectangular cell,
a coolant passage for cooling the battery cell extending along at least one of six faces of the battery cell;
a detection site provided in a central region of the widest of the six faces of the battery cell and in a region farther from the refrigerant passage than the central region, and the optical sensor is provided at these detection sites. In any one of claims 7 to 10,
two coolant passages for cooling the battery cells extending along the opposing faces of the battery cells,
the optical fiber has a portion arranged to extend from one side of both refrigerant passages of the battery cell to the other side on a surface that extends from one side of both refrigerant passages of the battery cell to the other side, and a plurality of the optical sensors are provided at intervals in this portion.

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