JP6569286B2 - Battery temperature estimation device - Google Patents

Description

  The present invention relates to a battery temperature estimation device for estimating the temperature of a battery in a battery unit mounted on a vehicle such as an automobile.

  For example, in a vehicle such as an automobile, a technique is known in which a storage battery (assembled battery module) including a plurality of single cells is used as a power source. In such an assembled battery, when the temperature of the unit cell becomes equal to or higher than a predetermined temperature, inconveniences such as a decrease in life occur. Therefore, in order to avoid such inconvenience, it is necessary to detect the temperature of the unit cell. Therefore, for example, a thermistor (temperature sensor) is attached to each unit cell, and the temperature of each unit cell is detected by these thermistors.

  In addition, as a prior art related to a storage battery including a plurality of single cells, a thermistor is attached to only some of the plurality of single cells, and the battery temperature detected by the thermistor and the acquired information on the assembled battery Based on the above, a technique for estimating the temperature of a unit cell that does not include a thermistor has been proposed (see, for example, Patent Documents 1 and 2).

JP 2003-185504 A JP 2014-26752 A

  However, depending on the type of the assembled battery, such as an assembled battery configured by laminating a plurality of laminated type single cells, it may be difficult to directly attach the thermistor to the single cell due to the structure. Further, when estimating the temperature of the unit cell, it is necessary to appropriately know the heat generation of the unit cell, and it is considered that there is room for improvement in technology in this respect.

  The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a battery temperature estimation device that can acquire the temperature of a battery without directly attaching a temperature sensor to the battery. It is in.

  Hereinafter, means for solving the above-described problems and the effects thereof will be described.

  The battery temperature estimation device (60) of the first invention is on a heat transfer path through which heat generated in the battery (34) is transferred, and at a position where the path length of heat transfer from the battery is small and large. Each is applied to a battery unit (10) provided with a first temperature sensor (51, 52) and a second temperature sensor (53) to estimate the temperature of the battery. The battery temperature estimation device (60) includes a first heat transfer resistor (R13, R14, R15, R33, R34, and R34) in a first path portion between the battery and the first temperature sensor in the heat transfer path. R35) is present, and a second heat transfer resistance (R20, R40) is present in the second path portion between the first temperature sensor and the second temperature sensor, and the battery in the heat transfer path Assuming that the generated heat is transferred to the first temperature sensor and the second temperature sensor through the heat transfer resistors, the difference between the detected temperatures of the first temperature sensor and the second temperature sensor is between the sensors. A temperature difference calculating means for calculating an estimated temperature difference, which is a temperature difference between the battery and the first temperature sensor, based on the temperature difference and the first heat transfer resistance and the second heat transfer resistance; 1 Temperature sensor detects the temperature difference By adding the estimated temperature difference calculated by means output, characterized in that it comprises a battery temperature calculation means for calculating the temperature of the battery.

  According to the above configuration, the first temperature sensor and the second temperature sensor are provided on the heat transfer path through which the heat generated in the battery is transmitted, and the battery and the first temperature sensor (first It is assumed that the first heat transfer resistance exists in one path portion and the second heat transfer resistance exists between the first temperature sensor and the second temperature sensor (second path portion). Under such a configuration, if the difference between the detected temperatures of the first temperature sensor and the second temperature sensor is obtained, the amount of heat transmitted through the second path portion based on the temperature difference and the second heat transfer resistance ( The amount of heat transferred to the second temperature sensor is determined. If the heat transfer amount in the second path portion and the heat transfer amount in the first path portion are associated in advance, the heat transfer amount in the first path portion (the heat transfer amount transmitted to the first temperature sensor) is also determined, As a result, the temperature difference between the battery and the first temperature sensor can be obtained based on the heat transfer amount of the first path section and the first heat transfer resistance.

  Therefore, in the above invention, the battery and the first temperature sensor are based on the difference between the detected temperatures of the first temperature sensor and the second temperature sensor (temperature difference between the sensors), the first heat transfer resistance, and the second heat transfer resistance. Temperature difference (estimated temperature difference) is calculated. Then, the battery temperature is calculated by adding the calculated estimated temperature difference to the temperature detected by the first temperature sensor. Thereby, it becomes possible to acquire the temperature of a battery, without attaching a temperature sensor directly with respect to a battery.

  In a second aspect of the invention, the battery unit includes a control board (12), the battery and the control board are electrically connected by a conductive member (44, 46), and the first temperature sensor includes: The temperature of a connection part where the conductive member and the control board are connected is detected, the second temperature sensor detects the temperature of a part of the control board separated from the connection part, and the first path part is The second path portion is configured to include the control board, and the first path portion has a heat transfer resistance (in the conductive member) as the first heat transfer resistance. R11) is included, and the second path portion includes a heat transfer resistance (R20) in the control board as the second heat transfer resistance, and the temperature difference calculating means is configured to include the conductive member. Heat transfer resistance and the control board That on the basis of the heat transfer resistance, and calculates the estimated temperature difference.

  In the configuration in which the temperature of the connection part between the conductive member and the control board is detected by the first temperature sensor, and the temperature of the part separated from the connection part in the control board is detected by the second temperature sensor, the heat transfer resistance and control in the conductive member are detected. The estimated temperature difference is calculated based on the heat transfer resistance in the substrate. In this case, the calculation accuracy of the estimated temperature difference can be improved by setting the heat transfer resistance according to each of the conductive member and the control board, and consequently the calculation accuracy of the battery temperature can be improved.

  According to a third aspect of the present invention, the first temperature sensor and the second temperature sensor are provided at positions spaced apart from each other on the control board, and the first path portion includes the first heat transfer resistor as the first heat transfer resistor, A heat transfer resistance in the conductive member, and a heat transfer resistance (R12) of a separated portion from the connection portion of the conductive member to the first temperature sensor in the control board, and the temperature difference calculating means includes: The estimated temperature difference is calculated based on the heat transfer resistances of the first path portion.

  Since each temperature sensor is provided on the control board, it is not necessary to provide a separate attachment member when attaching each temperature sensor to the heat transfer path. In such a configuration, the estimated temperature difference is calculated in consideration of the heat transfer resistance of the conductive member and the heat transfer resistance of the separated portion from the connection portion of the conductive member to the first temperature sensor on the control board. I tried to do it. In this case, the calculation accuracy of the estimated temperature difference can be further improved, and consequently the calculation accuracy of the battery temperature can be further improved.

  4th invention has the said battery in multiple numbers, and the electrically-conductive member (44,46) is respectively connected to the said mutually different battery, The said heat-transfer path | route is formed for every said electrically-conductive member, These each heat-transfer In the path, the first temperature sensor is provided for each path, and the second temperature sensor is provided in common for the path, and the temperature difference calculation means is configured to calculate the estimated temperature difference in each of the plurality of heat transfer paths. The battery temperature calculation means calculates the battery temperature by adding the estimated temperature difference to the temperature detected by the first temperature sensor in each of the plurality of heat transfer paths. .

  In the configuration in which the first temperature sensor is provided in the heat transfer path for each conductive member and the second temperature sensor is provided in the common path, an estimated temperature difference is calculated in each of the plurality of heat transfer paths, and the plurality of heat transfer paths In each of the above, the estimated temperature difference is added to the temperature detected by the first temperature sensor to calculate the battery temperature. In this case, the temperature of each battery can be calculated while suppressing an increase in the number of thermistors.

  A fifth invention includes a plurality of the batteries connected in series with each other, each of the plurality of batteries being provided with a positive electrode (35) and a negative electrode (36), and adjacent to each other in series connection. The positive electrode of one battery and the negative electrode of the other battery are connected to each other, and a conductive member (44, 46) is connected to the connecting portion. There is a first heat transfer path through which heat is transferred and a second heat transfer path through which the heat of the other battery is transferred. In the first heat transfer path, the first path portion is the positive electrode. And the conductive member. In the second heat transfer path, the first path portion is configured to include the negative electrode and the conductive member, and the first path of the first heat transfer path. In the part, as the first heat transfer resistance, the heat transfer resistance (R13) in the positive electrode and the conductive part In the first path portion of the second heat transfer path, as the first heat transfer resistance, the heat transfer resistance (R14) in the negative electrode, A heat transfer resistance (R11) in the conductive member, and as the temperature difference calculating means, a first temperature difference calculating means for calculating the estimated temperature difference in the first heat transfer path, and the second heat transfer. Second temperature difference calculation means for calculating the estimated temperature difference in the path, wherein the first temperature difference calculation means is based on the heat transfer resistance in the positive electrode and the estimated temperature of the first heat transfer path. The second temperature difference calculating means calculates the estimated temperature difference of the second heat transfer path based on the heat transfer resistance in the negative electrode, and the battery temperature calculating means In each of the heat transfer path and the second heat transfer path, the first By adding the estimated temperature difference of the temperature detected in degrees sensor and calculates the temperature of each battery.

  In the above configuration, the estimated temperature difference can be calculated with high accuracy by taking into account the heat transfer resistance of each of the two electrodes connected to each other in each battery adjacent in series. Thereby, the temperature of each battery can be calculated accurately.

  The sixth invention is characterized in that the battery has a plate shape and a plurality of stacked batteries constitute the assembled battery (31).

  In an assembled battery in which a plurality of plate-shaped batteries are stacked, it is particularly difficult to directly attach a temperature sensor to the battery because of its structure. In that respect, in the above configuration, since the battery temperature estimation device is applied to such a battery, the effect that the battery temperature can be acquired without directly attaching the temperature sensor to the battery can be obtained as a great effect.

The perspective view which shows the whole structure of a battery unit. The disassembled perspective view which decomposes | disassembles and shows the main structures of a battery unit. The perspective view of an assembled battery module. The disassembled perspective view which decomposes | disassembles and shows each component of an assembled battery module. The disassembled perspective view which decomposes | disassembles and shows each component of an assembled battery module. The front view which shows a battery assembly. The top view which shows a control board. The figure which shows a thermal network model. The figure which shows the heat-transfer resistance in each part of a heat-transfer path | route. The functional block diagram which shows the content of the battery temperature estimation process. The figure which shows a thermal network model in another form.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings. In the present embodiment, it is assumed that the power supply system is embodied in a vehicle, and this power supply system is charged and discharged in a power storage unit (power supply unit) for supplying electric power to various on-vehicle electric loads. Are sequentially controlled. The vehicle includes an engine that is an internal combustion engine, an in-vehicle ECU that controls the engine and other units, a generator (alternator) that is driven by the engine to generate power, and a power storage unit that is charged by the power generated by the generator. In particular, a lead storage battery and a lithium ion storage battery are used as the power storage unit. In the present embodiment, a Li battery unit (hereinafter simply referred to as a battery unit) that functions as a lithium ion storage battery will be described in detail.

  First, the overall configuration of the battery unit 10 will be described with reference to FIGS. 1 and 2. In the following description, for the sake of convenience, the vertical direction of the battery unit 10 is defined with reference to FIG. 1 in which the battery unit 10 is installed on a horizontal plane.

  The battery unit 10 includes, as main components, an assembled battery module 11 having a plurality of laminated unit cells, a control board 12 that controls charge / discharge of the assembled battery module 11, and the assembled battery module 11 and A housing case 13 for housing the control board 12 is provided. The housing case 13 includes a base 14 that is fixed to the mounting location of the battery unit 10, a cover 15 that is attached above the base 14, and an intermediate case 16 that is provided between the base 14 and the cover 15. The assembled battery module 11 and the control board 12 are arranged opposite to each other so that the assembled battery module 11 is on the bottom and the control board 12 is on the top, and are fixed to the base 14. Similarly, the cover 15 and the intermediate case 16 are respectively fixed to the base 14.

  Next, the configuration of each part of the battery unit 10 will be described.

  In the housing case 13, the base 14 is formed of a metal material such as aluminum. The base 14 has a bottom plate portion 21 formed in a substantially quadrangular shape, and a standing wall portion 22 provided upright from the peripheral edge portion or the substantially peripheral edge portion of the bottom plate portion 21. The bottom plate portion 21 is a placement portion on which the assembled battery module 11 is placed. In a state where the assembled battery module 11 is placed on the bottom plate portion 21, the assembled battery module 11 is surrounded by the standing wall portion 22. A heat sink 23 is attached to the base 14 for radiating heat generated in the assembled battery module 11 and the control board 12 to the outside.

  Similar to the base 14, the cover 15 is formed of a metal material such as aluminum. The cover 15 has a substantially rectangular shape and has substantially the same size as the base 14 in plan view.

  The intermediate case 16 is made of a synthetic resin material. The intermediate case 16 has an intermediate wall portion 25 that forms a substantially quadrangular ring shape in plan view. The lower end portion of the intermediate wall portion 25 is assembled to the upper end portion of the standing wall portion 22 of the base 14, and the intermediate wall portion 25 continuously extends upward from the standing wall portion 22 in the assembled state.

  Next, the assembled battery module 11 will be described. FIG. 3 is a perspective view of the assembled battery module 11, and FIGS. 4 and 5 are exploded perspective views showing the components of the assembled battery module 11 in an exploded manner. FIG. 6 is a front view showing a battery assembly constituting the assembled battery module 11.

  As shown in FIGS. 3 to 5, the assembled battery module 11 includes a battery assembly 31 having a plurality of (four in this embodiment) unit cells 33 and a battery holder to be assembled to the battery assembly 31. 32. The battery assembly 31 includes a plurality of unit cells 33 made of a laminate type battery, and the unit cells 33 are stacked one above the other.

  Each unit cell 33 has a square plate-shaped battery main body 34 (see FIG. 6) and a pair of plate-shaped electrode tabs 35 and 36 as electrode terminals connected to the battery main body 34. The battery main body 34 is accommodated in a flat container 37 made of a laminate film, and the peripheral edge of the flat container 37 is sealed to be sealed in the container 37. The battery body 34 of each unit cell 33 is provided in a state where it is stacked one above the other.

  The pair of electrode tabs 35 and 36 are respectively provided on the two opposite sides of the battery body 34. Each of these electrode tabs 35 and 36 is drawn out (extends) from the battery main body 34 toward the opposite side. Specifically, the thickness direction of the battery main body 34 (battery stacking direction in which the individual cells 33 are stacked) ) In a direction orthogonal to (hereinafter also referred to as a tab pulling direction). One of the electrode tabs 35, 36 is a positive electrode tab 35, and the other is a negative electrode tab 36. In the present embodiment, the positive electrode tab 35 is made of aluminum, and the negative electrode tab 36 is made of copper.

  As shown in FIG. 6, the unit cells 33 stacked one above the other are arranged in a direction in which the positive electrode tabs 35 and the negative electrode tabs 36 are alternated between the unit cells 33 adjacent to each other in the vertical direction. In this case, in each unit cell 33 adjacent in the vertical direction, the positive electrode tab 35 of one unit cell 33 and the negative electrode tab 36 of the other unit cell 33 face each other vertically and overlap each other, and are joined to each other at the overlapping portion. ing. Thereby, each cell 33 is connected in series.

  Among the unit cells 33 that are stacked one above the other, in the unit cell 33 arranged at the top, the positive electrode tab 35 (hereinafter referred to as “A”) is connected to the negative electrode tab 36 of the other unit cell 33. Not. Further, in the unit cell 33 arranged at the lowermost part, the negative electrode tab 36 (hereinafter referred to as “A”) is not connected to the positive electrode tab 35 of the other unit cell 33. The positive electrode tab 35A and the negative electrode tab 36A constitute the positive electrode terminal and the negative electrode terminal of a plurality of unit cells 33 (series circuit composed of) connected in series, respectively, and the tab pull-out directions are the same.

  A double-sided adhesive type adhesive tape 38 is interposed between each unit cell 33 (specifically, each battery body 34). The unit cells 33 are integrated by the adhesion of the adhesive tape 38. A rigid plate 39 made of an iron plate is attached to the uppermost unit cell 33 among the unit cells 33 by an adhesive tape 38.

  The battery holder 32 is attached to the first holding portion 41 that is assembled to the electrode tabs 35 and 36 on one side of the two opposite sides of each unit cell 33 and the electrode tabs 35 and 36 on the other side. It has the 2nd holding | maintenance part 42 assembled | attached and the connection part 43 which connects each these holding | maintenance parts 41 and 42 mutually. These parts are integrally formed of, for example, a synthetic resin material.

  The first holding portion 41 includes a plurality of (three) plate-like (three) plates that are electrically connected to the electrode tabs 35 and 36 on one side of both sides of the battery assembly 31 (two opposing sides of the unit cell 33). A bus bar 44 (44a, 44b, 44c) is provided. Each of these bus bars 44a to 44c is provided in a cantilever state such that the bus bars 44a to 44c are arranged in the battery stacking direction and the plate surfaces face up and down. The bus bars 44a to 44c are arranged in the order of the bus bar 44a, the bus bar 44b, and the bus bar 44c from the top to the bottom.

  Among the bus bars 44a to 44c, the bus bar 44a is joined to the positive electrode tab 35A in a state where the plate surface is superimposed on the positive electrode tab 35A. That is, the bus bar 44 a is connected to the positive terminal of the series circuit composed of the plurality of single cells 33. The bus bar 44b is joined to the electrode tabs 35 and 36 in a state where the plate surfaces are superimposed on the electrode tabs 35 and 36 in a joined state. The bus bar 44c is joined to the negative electrode tab 36A in a state where the plate surface is superimposed on the negative electrode tab 36A.

  The second holding portion 42 includes a plurality of (two) plate-like bus bars 44 (44d, 44e) that are electrically connected to the electrode tabs 35, 36 on the other side of both sides of the battery assembly 31. ing. Each of these bus bars 44d, 44e is also provided in a cantilever state so that it is also aligned in the battery stacking direction and the plate surface faces up and down. Of the bus bars 44d and 44e, the bus bar 44d is disposed on the upper side and the bus bar 44e is disposed on the lower side. The bus bars 44d and 44e are joined to the electrode tabs 35 and 36 with their plate surfaces superimposed on the electrode tabs 35 and 36 in a joined state.

  The first holding portion 41 is provided with three bus bars 46 (46a, 46b, 46c) connected to the bus bars 44a to 44c, respectively. In this case, the bus bar 46a is connected to the bus bar 44a, the bus bar 46b is connected to the bus bar 44b, and the bus bar 46c is connected to the bus bar 44c. The second holding part 42 is provided with two bus bars 46 (46d, 46e) connected to the bus bars 44d, 44e, respectively. In this case, the bus bar 46d is connected to the bus bar 44d, and the bus bar 46e is connected to the bus bar 44e. Each of the bus bars 46a to 46e is provided so as to extend upward, and the tip thereof is connected to the control board 12 (see FIG. 7). Thereby, it is possible to detect the terminal voltage for each single cell 33 via the bus bars 44a to 44e and the bus bars 46a to 46e connected to each other.

  The first holding unit 41 is provided with two power terminals 47 connected to the bus bar 44a. That is, these power terminals 47 are connected to a positive terminal of a series circuit composed of a plurality of single cells 33.

  Next, the structure regarding the control board 12 is demonstrated. FIG. 7 is a plan view showing the control board 12. In FIG. 7, the bus bars 46 a to 46 e and the power terminal 47 connected to the control board 12 are also illustrated.

  As shown in FIG. 7, the control board 12 is a rectangular board (rectangular board) printed board having a circuit pattern formed on the board surface. As described above, the control board 12 is assembled on the assembled battery module 11, and in the assembled state, the long side direction of the board is arranged in the tab drawing direction of the electrode tabs 35 and 36.

  Various electronic components are mounted on the board surface of the control board 12. These electronic components include a control unit 60 (CPU) that executes charge / discharge control processing of the assembled battery module 11, a switching element 56, and the like. In FIG. 7, for convenience of illustration, the control unit 60 is shown separated from the control board 12.

  The control board 12 is formed with a through hole 55 penetrating in the thickness direction at a substantially central portion thereof. The switching element 56 is arranged on one side (lower side in FIG. 7) of both sides of the through-hole 55 in the short side direction of the substrate on the control board 12, and is arranged on the other side (upper side in FIG. 7). Absent. In this case, the switching element 56 does not exist on the other side of the through hole 55 on the control board 12. Further, from the viewpoint that the switching element 56 is a heat generating element that generates heat, the region can also be referred to as an unheated region 12a in which no heat generating element exists.

  The bus bars 46a to 46c of the first holding part 41 and the bus bars 46d and 46e of the second holding part 42 are connected to the control board 12 at positions opposite to each other in the board longitudinal direction. Each of these bus bars 46 a to 46 e is connected to the control board 12 in a state of being inserted into holes 58 a to 58 e formed in the control board 12. In addition, all of these bus bars 46 a to 46 e are connected to the unheated region 12 a in the control board 12.

  Each power terminal 47 of the first holding part 41 is connected to the control board 12 in the vicinity of the connection part of the first holding part 41 with the bus bars 46a to 46c. These power terminals 47 are connected to the control board 12 in a state of being inserted into holes 59 formed in the control board 12.

  On the control board 12, the thermistor 51 that detects the temperature of the bus bar 46d (the temperature of the connection part between the control board 12 and the bus bar 46d) and the temperature of the bus bar 46e (the temperature of the connection part between the control board 12 and the bus bar 46e) And a thermistor 52 for detecting. The thermistor 51 is disposed in the vicinity of the bus bar 46d on the control board 12, and the thermistor 52 is disposed in the vicinity of the bus bar 46e on the control board 12.

  The arrangement of the thermistors 51 and 52 will be described in detail. The bus bars 46d and 46e are arranged side by side in the lateral direction of the board on the control board 12, and the thermistors 51 and 52 are arranged along the arrangement direction of the bus bars 46d and 46e. Is arranged. In this case, the thermistors 51 and 52 are arranged on the center side (same side) in the substrate longitudinal direction with respect to the bus bars 46d and 46e. The thermistors 51 and 52 are symmetrically arranged with respect to the center position of the bus bars 46d and 46e in the direction in which the bus bars 46d and 46e are arranged (the short side direction of the board). Is larger than the interval between the bus bars 46d and 46e.

  Incidentally, on the control board 12, the bus bars 46d and 46e are located farther from the switching element 56 than the bus bars 46a to 46c. For this reason, the above-described configuration in which the thermistors 51 and 52 are disposed in the vicinity of the bus bars 46d and 46e is a configuration in which the thermistors 51 and 52 are disposed in the vicinity of the bus bars 46a to 46c (in other words, the thermistors 51 and 52 provide the bus bar 46a. The thermistors 51 and 52 can be arranged at positions away from the switching element 56 (and thus the heating element) as compared with the configuration of detecting the temperature of .about.46c. Therefore, when the thermistors 51 and 52 detect the temperature of the bus bar 46, the influence of heat from the switching element 56 can be reduced.

  On the control board 12, in addition to the thermistors 51 and 52, a thermistor 53 for detecting the temperature of the control board 12 is mounted. Unlike the thermistors 51 and 52 described above, the thermistor 53 is disposed on the control board 12 at a position away from the bus bars 46d and 46e. Therefore, the thermistor 53 detects the temperature of the control board 12 with almost no influence from the temperature from the bus bars 46d and 46e.

  The thermistor 53 is arranged on the center side in the substrate longitudinal direction with respect to the bus bars 46d and 46e. That is, the thermistor 53 is disposed on the same side as the thermistors 51 and 52 with respect to the bus bars 46d and 46e, and is opposite to the bus bars 46d and 46e across the thermistors 51 and 52 when viewed in the longitudinal direction of the substrate. Is located. The thermistor 53 is disposed on the control substrate 12 at a substantially central portion in the substrate longitudinal direction. In this case, the distance between the thermistor 53 and each of the bus bars 46 a to 46 c of the first holding part 41 and the distance between the thermistor 53 and each of the bus bars 46 d and 46 e of the second holding part 42 are substantially the same.

  Further, the thermistor 53 is arranged in the non-heated area 12 a on the control board 12. For this reason, the thermistor 53 is also less affected by heat from the switching element 56.

  Each of the thermistors 51 to 53 is connected to the control unit 60. Detection results (detection temperatures) are input to the control unit 60 from the thermistors 51 to 53, respectively. And the control part 60 implements the below-mentioned temperature estimation process which estimates the temperature of each cell 33 based on the detected temperature input from each of these thermistors 51-53.

  By the way, in the configuration of the battery unit 10 described above, heat generated in each unit cell 33 (specifically, the battery main body 34) is transmitted to the control board 12 via the electrode tabs 35 and 36 and the bus bars 44 and 46. Can be considered. Accordingly, in the battery unit 10, the electrode tabs 35 and 36, the bus bars 44 and 46, and the control board 12 constitute a heat transfer path through which heat generated in each battery body 34 is transmitted. Therefore, in this embodiment, a thermal circuit network model that models the movement of heat in the heat transfer path is created, and the temperature of each battery body 34 is estimated using the thermal circuit network model. Hereinafter, a battery temperature estimation device for estimating the battery temperature will be described.

  First, a thermal circuit network model serving as a basis for battery temperature estimation will be described. FIGS. 8A and 8B are diagrams showing the thermal network model. In FIG. 8A, the thermal network model including the structure of the battery unit 10 is shown. In FIG. 8B, the thermal network model in FIG. 8A is transformed into an equivalent model. Show.

  As shown in FIG. 8A, each single battery 33 (specifically, the battery main body 34) serving as a heat source in the thermal circuit network model is arranged in a vertically stacked state as described above. Each of these unit cells 33 (33a to 33d) becomes a first unit cell 33a, a second unit cell 33b, a third unit cell 33c, and a fourth unit cell 33d in order from the upper one to the lower one. Yes. Further, in the following, for convenience, the symbols of the battery bodies 34 of the unit cells 33a to 33d are denoted by a to d, respectively.

  The heat transfer path includes a heat transfer path K1 through which heat generated in the battery bodies 34a and 34b of the first unit cell 33a and the second unit cell 33b is transmitted, and the third unit cell 33c and the fourth unit cell 33d. There is a heat transfer path K2 through which heat generated in each battery body 34c, 34d is transferred. A thermistor 51 and a thermistor 53 are provided on the heat transfer path K1. In this case, on the heat transfer path K1, the thermistor 51 is disposed at a position where the path length of heat transfer from the battery bodies 34a, 34b is small, and the thermistor 53 is positioned at a position where the path length of heat transfer from the battery bodies 34a, 34b is large. Has been placed.

  On the other hand, a thermistor 52 and a thermistor 53 are provided on the heat transfer path K2. In this case, on the heat transfer path K2, the thermistor 52 is disposed at a position where the path length of heat transfer from the battery bodies 34c, 34d is small, and the thermistor 53 is positioned at a position where the path length of heat transfer from the battery bodies 34c, 34d is large. Is arranged. As described above, the thermistor 51 and the thermistor 52 are provided for each of the heat transfer paths K1 and K2, whereas the thermistor 53 is provided in common for each of the heat transfer paths K1 and K2. Each thermistor 51, 52 corresponds to a first temperature sensor, and the thermistor 53 corresponds to a second temperature sensor.

  Subsequently, the heat transfer path K1 will be described in detail.

  As shown in FIGS. 8A and 8B, the heat transfer path K1 is a pair of electrode tabs 35 and 36 of the first unit cell 33a and the second unit cell 33b connected to each other. It has a tab path portion K1a, K1b, a bus bar path portion K1c configured to include the bus bars 44d, 46d, and a substrate path portion K1d configured by the control board 12.

  The tab path portion K1a is constituted by the negative electrode tab 36 of the first single battery 33a, and is connected to the battery body 34a. The tab path portion K1b is constituted by the positive electrode tab 35 of the second cell 33b, and is connected to the battery body 34b. A heat transfer resistance R13 exists in the tab path portion K1a, and a heat transfer resistance R14 exists in the tab path portion K1b.

  The bus bar path portion K1c is connected to each of the tab path portions K1a and K1b. The bus bar path portion K1c is a path from the connecting portion of each tab path portion K1a, K1b to the thermistor 51. Specifically, the bus bar path portion K1c includes a path portion K1e configured by the bus bars 44d and 46d, and a path portion K1f configured by a separated portion from the connection portion 62 to the thermistor 51 on the control board 12 to the bus bar 46d. (See FIG. 8B). The path portion K1e has a heat transfer resistance R11, and the path portion K1f has a heat transfer resistance R12. In this case, the sum of the heat transfer resistance R11 and the heat transfer resistance R12 becomes the heat transfer resistance R15 of the bus bar path portion K1c.

  The substrate path portion K1d is a path from the thermistor 51 to the thermistor 53. A heat transfer resistance R20 exists in the substrate path portion K1d. The heat transfer resistance in each part of the heat transfer path K1 is summarized as shown in FIG.

  The heat transfer path K2 has basically the same configuration as the heat transfer path K1. That is, the heat transfer path K2 includes a pair of tab path portions K2a and K2b configured by the electrode tabs 35 and 36 of the third cell 33c and the fourth cell 33d, and bus bars 44e and 46e. A bus bar path portion K2c and a board path portion K2d constituted by the control board 12 are provided. A heat transfer resistance R33 exists in the tab path portion K2a, and a heat transfer resistance R34 exists in the tab path portion K2b.

  The bus bar path portion K2c is a path from the connecting portion of each tab path portion K2a, K2b to the thermistor 52. The bus bar path portion K2c includes a path portion K2e configured by the bus bars 44e and 46e and a path portion K2f configured by a separated portion from the connection portion 63 to the thermistor 52 on the control board 12 to the bus bar 46e. . The path portion K2e has a heat transfer resistance R31, and the path portion K2f has a heat transfer resistance R32. In this case, the sum of the heat transfer resistance R31 and the heat transfer resistance R32 becomes the heat transfer resistance R35 of the bus bar path portion K2c.

  The substrate path portion K2d is a path from the thermistor 52 to the thermistor 53. A heat transfer resistance R40 exists in the substrate path portion K2d.

  Next, the flow of heat when heat generated in the battery main body 34 of each unit cell 33 is transmitted through the heat transfer paths K1 and K2 will be described. First, the flow of heat when heat generated in the battery bodies 34a and 34b of the first unit cell 33a and the second unit cell 33b is transmitted through the heat transfer path K1 will be described.

  As shown in FIG. 8B, the heat generated in the battery body 34a of the first unit cell 33a travels along the tab path part K1a to the bus bar path part K1c, and is generated in the battery body 34b of the second unit cell 33b. The heat travels along the tab path portion K1b and moves to the bus bar path portion K1c. In this case, if the heat transfer amount (heat transfer amount) in the tab path portion K1a is Qa and the heat transfer amount in the tab path portion K1b is Qb, the heat transfer amount in the bus bar path portion K1c and further the substrate path portion K1d is Qa + Qb.

  Assuming such a heat transfer amount, the temperature difference at both ends of the tab path portion K1a is represented by Qa × R13, and the temperature difference at both ends of the tab path portion K1b is represented by Qb × R14. Further, the temperature difference between both ends of the bus bar path portion K1c is represented by (Qa + Qb) × R15. Therefore, when the temperature of the battery body 34a of the first unit cell 33a is T1, and the temperature of the battery body 34b of the second unit cell 33b is T2, these temperatures T1 and T2 can be expressed by the following formula 1, respectively. it can. In Equation 1, Ta is a temperature detected by the thermistor 51.

また、サーミスタ５３による検出温度をＴｂとした場合、各サーミスタ５１，５３の検出温度の差はＴａ−Ｔｂで表すことができる。この検出温度の差Ｔａ−Ｔｂは、基板経路部Ｋ１ｄの両端における温度差に相当する。また、基板経路部Ｋ１ｄにおける伝熱量はＱａ＋Ｑｂとなっているため、この場合、Ｑａ＋Ｑｂを以下の式２で表すことができる。

Further, when the temperature detected by the thermistor 53 is Tb, the difference between the temperatures detected by the thermistors 51 and 53 can be expressed by Ta-Tb. This detected temperature difference Ta-Tb corresponds to a temperature difference at both ends of the substrate path portion K1d. Further, since the heat transfer amount in the substrate path part K1d is Qa + Qb, in this case, Qa + Qb can be expressed by the following formula 2.

この式２を上記式１に代入すると、下記の式３が導かれる。

Substituting Equation 2 into Equation 1 yields Equation 3 below.

これにより、伝熱経路Ｋ１上の各伝熱抵抗Ｒ１３，Ｒ１４，Ｒ１５，Ｒ２０と、伝熱経路Ｋ１上の各サーミスタ５１，５３の検出温度Ｔａ，Ｔｂとがわかれば、それらに基づき各電池本体３４ａ，３４ｂの温度Ｔ１，Ｔ２を算出することが可能となる。

Accordingly, if the heat transfer resistances R13, R14, R15, R20 on the heat transfer path K1 and the detected temperatures Ta, Tb of the thermistors 51, 53 on the heat transfer path K1 are known, each battery body is based on them. The temperatures T1 and T2 of 34a and 34b can be calculated.

  Here, the heat flow generated in each of the battery main bodies 34a and 34b of the first cell 33a and the second cell 33b will be further described. The heat generated in the battery main body 34a is converted into the tab path portion K1a and the bus bar path portion. It flows to the thermistor 53 through K1c and the substrate path portion K1d. In this case, the heat transfer path Ka through which the heat of the battery main body 34a is transmitted has a tab path portion K1a, a bus bar path portion K1c, and a substrate path portion K1d. In the heat transfer path Ka, the tab path portion K1a and the bus bar path portion K1c constitute a first path portion, and the substrate path portion K1d constitutes a second path portion. Accordingly, the heat transfer resistances R13 and R15 of the tab path portion K1a and the bus bar path portion K1c exist in the first heat transfer resistance, respectively, and the heat transfer resistance R20 of the substrate path portion K1d corresponds to the second heat transfer resistance.

  On the other hand, the heat generated in the battery body 34b flows to the thermistor 53 through the tab path portion K1b, the bus bar path portion K1c, and the board path portion K1d. In this case, the heat transfer path through which the heat of the battery body 34b is transmitted includes the tab path portion K1b, the bus bar path portion K1c, and the board path portion K1d. In the heat transfer path Kb, the tab path portion K1b and the bus bar path portion K1c constitute a first path portion, and the substrate path portion K1d constitutes a second path portion. Therefore, the heat transfer resistances R14 and R15 of the tab path portion K1b and the bus bar path portion K1c exist in the first heat transfer resistance, respectively, and the heat transfer resistance R20 of the substrate path portion K1d corresponds to the second heat transfer resistance.

  Thus, when the flow of heat is followed for each battery main body 34a, 34b, the heat transfer path K1 includes two heat transfer paths Ka, Kb respectively corresponding to the battery main bodies 34a, 34b. I understand that. In this case, each of the heat transfer paths Ka and Kb includes a tab path part K1a and K1b provided for each path, and a bus bar path part K1c and a board path part K1d provided in common to the paths. Yes.

  Incidentally, the above expression 3 (the above expression 1) is an expression corresponding to the heat transfer path Ka, and the second term of the above expression is the temperature at both ends of the bus bar path portion K1c constituting the heat transfer path Ka. This corresponds to the difference, and the third term corresponds to the temperature difference at both ends of the tab path portion K1a that similarly constitutes the heat transfer path Ka. Further, the lower expression of the above expression 3 (the above expression 1) is an expression corresponding to the heat transfer path Kb, and the second term of the lower expression is a temperature at both ends of the bus bar path portion K1c constituting the heat transfer path Kb. This corresponds to the difference, and the third term also corresponds to the temperature difference at both ends of the tab path portion K1b constituting the heat transfer path Kb.

  In this case, the heat transfer path Ka corresponds to the second heat transfer path, and the heat transfer path Kb corresponds to the first heat transfer path.

  Next, the flow of heat when heat generated in the battery main bodies 34c and 34d of the third unit cell 33c and the fourth unit cell 33d is transmitted through the heat transfer path K2 will be described. Since the heat transfer path K2 has the same configuration as the heat transfer path K1, as described above, the heat flow in the heat transfer path K2 is basically the same as the heat flow in the heat transfer path K1. is there. For this reason, only a brief explanation will be given here.

  The heat generated in the battery body 34c flows to the thermistor 53 through the tab path portion K2a, the bus bar path portion K2c, and the board path portion K2d. Therefore, the heat transfer path Kc through which the heat of the battery main body 34c is transmitted includes the tab path portion K2a, the bus bar path portion K2c, and the substrate path portion K2d. Further, the heat generated in the battery main body 34d flows to the thermistor 53 through the tab path portion K2b, the bus bar path portion K2c, and the board path portion K2d. Therefore, the heat transfer path Kd through which the heat of the battery main body 34d is transmitted includes the tab path portion K2b, the bus bar path portion K2c, and the substrate path portion K2d. Accordingly, the heat transfer path K2 includes heat transfer paths Kc and Kd corresponding to the battery bodies 34c and 34d, respectively. In heat transfer path K2, heat transfer path Kc corresponds to the second heat transfer path, and heat transfer path Kd corresponds to the first heat transfer path.

  Next, battery temperature estimation processing for estimating the temperature of each of the battery main bodies 34a to 34d using the above-described thermal circuit network model will be described. The battery temperature estimation process is performed by the control unit 60. FIG. 10 is a functional block diagram showing the contents of the battery temperature estimation process. Each functional block in FIG. 10 is realized by the control unit 60.

  Moreover, this battery temperature estimation process is implemented separately for each heat transfer path K1, K2. That is, a temperature estimation process for estimating the temperature of each battery body 34a, 34b connected to the heat transfer path K1, and a temperature estimation process for estimating the temperature of each battery body 34c, 34d connected to the heat transfer path K2. Each is implemented individually. Since each of these temperature estimation processes is the same process, the temperature estimation process for estimating the temperatures of the battery bodies 34a and 34b will be described below.

  As shown in FIG. 10, the first temperature difference calculation unit 71 subtracts the detected temperature Tb from the thermistor 53 from the detected temperature Ta from the thermistor 51, so that the difference ΔT (= Ta−Tb) between these detected temperatures Ta and Tb. Is calculated. This temperature difference ΔT corresponds to the “temperature difference between sensors”.

  Based on the temperature difference ΔT calculated by the first temperature difference calculation unit 71, the second temperature difference calculation unit 72 sets the difference (temperature difference) between the temperature T1 of the battery body 34a and the detected temperature Ta of the thermistor 51 as y1. calculate. This temperature difference y1 is expressed by the following formula 4.

温度差ｙ１は、上記式３（詳しくはＴ１に関する式）の第２項と第３項との和に相当する。また、式４中の各伝熱抵抗Ｒ１３，Ｒ１５，Ｒ２０はいずれも適合値とされ、またＱａ×Ｒ１３についても適合値とされている。なお、この場合、温度差ｙ１が「推定温度差」に相当し、第２温度差算出部７２が温度差算出手段及び第２温度差算出手段に相当する。

The temperature difference y1 corresponds to the sum of the second term and the third term of the above formula 3 (specifically, the formula related to T1). In addition, each of the heat transfer resistances R13, R15, and R20 in Equation 4 is an appropriate value, and Qa × R13 is also an appropriate value. In this case, the temperature difference y1 corresponds to an “estimated temperature difference”, and the second temperature difference calculator 72 corresponds to a temperature difference calculator and a second temperature difference calculator.

  The adding unit 73 adds the temperature difference y1 (T1-Ta) calculated by the second temperature difference calculating unit 72 and the temperature detected by the thermistor 51. Thereby, the temperature T1 of the battery main body 34a is calculated (estimated) (see also the above formula 3). The adding unit 73 corresponds to battery temperature calculation means.

  Based on the temperature difference ΔT calculated by the first temperature difference calculation unit 71, the third temperature difference calculation unit 74 sets the difference (temperature difference) between the temperature T2 of the battery body 34b and the detected temperature Ta of the thermistor 51 as y2. calculate. This temperature difference y2 is expressed by the following formula 5.

温度差ｙ２は、上記式３（詳しくはＴ２に関する式）の第２項と第３項との和に相当する。また、式５中の伝熱抵抗Ｒ１４，Ｒ１５，Ｒ２０はいずれも適合値とされ、またＱｂ×Ｒ１４についても適合値とされている。ちなみに、Ｑｂ×Ｒ１４を式４中のＱａ×Ｒ１３と比較すると、Ｑｂ×Ｒ１４はＱａ×Ｒ１３よりも大きな値として設定されている。これは、電池本体３４ａと電池本体３４ｂとで熱の発生量を比べた場合、内側に位置する電池本体３４ｂの方が熱の発生量が多くなると想定されるからである。なお、この場合、温度差ｙ２が「推定温度差」に相当し、第３温度差算出部７４が温度差算出手段及び第１温度差算出手段に相当する。

The temperature difference y2 corresponds to the sum of the second term and the third term of the above formula 3 (specifically, the formula related to T2). In addition, the heat transfer resistances R14, R15, and R20 in Equation 5 are all appropriate values, and Qb × R14 is also an appropriate value. Incidentally, when Qb × R14 is compared with Qa × R13 in Expression 4, Qb × R14 is set as a larger value than Qa × R13. This is because when the amount of heat generation is compared between the battery body 34a and the battery body 34b, it is assumed that the amount of heat generation is greater in the battery body 34b located inside. In this case, the temperature difference y2 corresponds to the “estimated temperature difference”, and the third temperature difference calculator 74 corresponds to the temperature difference calculator and the first temperature difference calculator.

  The adding unit 75 adds the temperature difference y2 (T2-Ta) calculated by the third temperature difference calculating unit 74 and the temperature detected by the thermistor 51. Thereby, the temperature T2 of the battery main body 34b is calculated (estimated) (see also the above formula 3). The adding unit 75 corresponds to battery temperature calculation means.

  As described above, in the temperature estimation process, the temperatures T1 and T2 of the battery bodies 34a and 34b are calculated for the heat transfer paths Ka and Kb of the battery bodies 34a and 34b, respectively. That is, the estimated temperature differences (T1-Ta) and (T2-Ta) are calculated by the temperature difference calculation units 72 and 74 for each of the heat transfer paths Ka and Kb, and each addition is performed based on the calculated estimated temperature difference. The temperatures 73 and 75 of the battery main bodies 34a and 34b are calculated by the units 73 and 75, respectively.

  Further, the temperature estimation process for estimating the temperatures T3 and T4 of the battery bodies 34c and 34d will be briefly described. Regarding the process, as in the temperature estimation process, the heat transfer paths Kc, The temperatures T3 and T4 of the battery bodies 34c and 34d are calculated for each Kd. That is, the estimated temperature difference is calculated by the temperature difference calculation unit (corresponding to the temperature difference calculation means) for each heat transfer path Kc, Kd, and the calculated estimated temperature difference is added to the detected temperature of the thermistor 52 by the adding unit. Thus, the temperatures T3 and T4 of the battery bodies 34c and 34d are calculated.

  According to the embodiment described in detail above, the following excellent effects can be obtained.

  The temperature of each battery body 34 was estimated using a thermal circuit network model constructed assuming the amount of heat transferred from the battery body 34. Specifically, based on the detected temperature difference between the thermistors 51 and 52 and the thermistor 53, the heat transfer resistances R13, R14 and R15 between the battery body 34 and the thermistors 51 and 52, and the heat transfer resistance R20 between the thermistors. The temperature difference between the battery body 34 and the thermistors 51 and 52 was calculated. Then, the temperature T1, T2 of the battery body 34 was calculated by adding the temperature difference between the battery body 34 and the thermistors 51, 52 to the detected temperature of the thermistors 51, 52. Thereby, the temperature of the battery main body 34 can be acquired without directly attaching the thermistor to the battery main body 34.

  In the configuration in which the battery body 34 (unit cell 33) and the control board 12 are connected by the bus bars 44 and 46, the thermistor 51 detects the temperature of the connection portion between the bus bar 46 and the control board 12, and the thermistor 53 controls the control board. 12, the temperature of the part separated from the connection portion is detected. Further, in the heat transfer paths Ka and Kb, a heat transfer resistance R11 in the bus bars 44 and 46 (path portion K1e) is set between the battery bodies 34a and 34b and the thermistor 51, and a control board is provided between the thermistors 51 and 53. The heat transfer resistance R20 at 12 (substrate path portion K1d) was set. In this case, the estimated temperature differences (T1−Ta) and (T2−Ta) are calculated based on the heat transfer resistances R11 and R20 of the bus bars 44 and 46 and the control board 12. Therefore, the calculation accuracy of the estimated temperature differences (T1−Ta) and (T2−Ta) can be improved by setting the heat transfer resistance corresponding to each of the bus bars 44 and 46 and the control board 12, and the battery temperature The calculation accuracy of T1 and T2 can be improved.

  Since the thermistors 51 and 53 are provided on the control board 12, respectively, it is not necessary to provide a separate attachment member when attaching the thermistors 51 and 53 to the heat transfer paths Ka and Kb. And in such a structure, between the battery main bodies 34a and 34b and the thermistor 51 in the heat transfer paths Ka and Kb, the heat transfer resistance R11 in the bus bars 44 and 46 (path portion K1e) and the bus bar in the control board 12 46 are set as heat transfer resistances, and the estimated temperature differences (T1−Ta), (T2−2) are set based on the heat transfer resistances R11 and R12. Ta) was calculated. In this case, the calculation accuracy of the estimated temperature difference can be further improved by taking these heat transfer resistances R11 and R12 into account, and the calculation accuracy of the battery temperature can be further improved.

  In the configuration in which the bus bars 44d, 46d (44e, 46e) are connected to the battery bodies 34a (34c) different from each other, a heat transfer path Ka (Kc) is formed for each bus bar. Therefore, in each of the heat transfer paths Ka (Kc), the thermistors 51 and 52 are provided for each path, and the thermistor 53 is provided in common for the paths. In this case, the temperature of each battery body 34a, 34c can be calculated while suppressing an increase in the number of thermistors.

  The bus bars 44 and 46 are connected to the connection portions between the electrode tabs 35 and 36 of the battery bodies 34a and 34b adjacent to each other in series connection, and a heat transfer path Ka through which the heat of the battery body 34a is transmitted is provided. The bus bars 44 and 46 and the negative electrode tab 36 are included, and the heat transfer path Kb through which the heat of the battery body 34 b is transmitted includes the bus bars 44 and 46 and the positive electrode tab 35. In this configuration, the second temperature difference calculation unit 72 calculates the estimated temperature difference (T1-Ta) on the heat transfer path Ka side based on the heat transfer resistance R13 in the negative electrode tab 36 (tab path portion K1a). The estimated temperature difference (T2-Ta) on the heat transfer path Kb side is calculated by the third temperature difference calculation section 74 based on the heat transfer resistance R14 in the positive electrode tab 35 (tab path section K1b). Then, the temperature difference T1, T2 of each battery body 34a, 34b is calculated by adding the calculated estimated temperature difference to the detected temperature Ta of the thermistor 51 by the adding units 73, 75. In this case, since it is possible to calculate the estimated temperature difference with high accuracy in consideration of the heat transfer resistances R13 and R14 of the electrode tabs 35 and 36, the temperatures T1 and T2 of the battery bodies 34a and 34b are accurately calculated. be able to.

  Further, since the thermistors 51 and 53 are provided in the common path of the heat transfer paths Ka and Kb (path consisting of the bus bar path portion K1c and the board path portion K1d), the temperatures T1 and T2 of the battery bodies 34a and 34b are calculated. In doing so, these thermistors 51 and 53 can be used in common. Therefore, it is possible to calculate the temperatures T1 and T2 of the battery main bodies 34a and 34b while suppressing an increase in the number of thermistors.

  In the battery assembly 31 in which a plurality of plate-shaped battery bodies 34 (unit cells 33) are stacked, it is particularly difficult to directly attach a thermistor to the battery body 34 due to its structure. In that respect, in the above embodiment, since the battery temperature estimation device is applied to the battery main body 34, the effect that the battery temperature can be obtained without directly attaching the thermistor to the battery main body 34 is obtained as a great effect. Can do.

  The temperature T1 to T4 of each of the battery bodies 34a to 34d is calculated using a thermal circuit network model in which the heat transfer paths Ka to Kd for the battery bodies 34a to 34d constituting the battery assembly 31 are constructed. did. Thereby, temperature T1-T4 of all the battery main bodies 34a-34d which comprise the battery assembly 31 is acquirable.

  You may change the said embodiment as follows, for example.

  (1) In the above embodiment, between the battery main bodies 34a and 34b and the thermistor 51 (corresponding to the first path portion) in the heat transfer paths Ka and Kb (corresponding to the first path portion), as the first heat transfer resistance, the tab path portions K1a and K1b are transferred. The heat resistances R13 and R14, the heat transfer resistance R11 of the path portion K1e, and the heat transfer resistance R12 of the path portion K1f are set. Of these heat transfer resistances R13 (R14), R11, and R12, for example, the path A thermal circuit model in which the heat transfer resistance R12 of the part K1f is omitted may be constructed. Assuming that the distance from the connecting portion 62 to the bus bar 46d to the thermistor 51 is short on the control board 12, such omission is possible. Further, instead of or in addition to omitting the heat transfer resistance R12 of the path portion K1f, a thermal circuit model in which the heat transfer resistance R13 (R14) of the tab path portions K1a and K1b is omitted may be constructed. Even using these thermal circuit models, the estimated temperature difference can be calculated based on the set heat transfer resistance (first heat transfer resistance).

  (2) In the above embodiment, the thermistors 51 and 52 are connected to the bus bar 46d, 46 on the control board 12 so that the thermistors 51, 52 as the first temperature sensors detect the temperature of the connection portion between the bus bars 46d, 46e and the control board 12. However, the thermistors 51 and 52 may be arranged at positions away from the bus bars 46 d and 46 e on the control board 12. In this case, the thermistors 51 and 52 detect the temperature of the control board 12.

  The thermistors 51 and 52 are not necessarily provided on the control board 12, and may be provided on the bus bars 46d and 46e, for example.

  (3) Although the thermistor 53 as the second temperature sensor is provided on the control board 12 in the above embodiment, the thermistor 53 is not necessarily provided on the control board 12. For example, the thermistor 53 is provided above the control board 12 in the battery unit 10 (accommodating case 13) (in other words, on the opposite side of the battery assembly 31 with the control board 12 in between). It is conceivable to detect the ambient temperature in 13. In this case, in the heat transfer path Ka, the second path portion from the thermistor 51 to the thermistor 53 is constituted by air. Therefore, the heat transfer resistance in the air is set as the second heat transfer resistance of the second path portion.

  (4) In the above embodiment, the thermistors 51 and 52 (first temperature sensors) are provided in the heat transfer path K1 (heat transfer paths Ka and Kb) and the heat transfer path K2 (heat transfer paths Kc and Kd), respectively. By changing this, the first temperature sensor may be provided in common to the heat transfer paths K1, K2, that is, in common to the heat transfer paths Ka to Kd. By doing so, the number of first temperature sensors can be reduced.

  In the above embodiment, the thermistor 53 (second temperature sensor) is provided in common for the heat transfer path K1 (heat transfer paths Ka, Kb) and the heat transfer path K2 (heat transfer paths Kc, Kd). (Second temperature sensor) may be provided in each of the heat transfer paths K1, K2.

  (5) In the above embodiment, the temperature of each battery body 34a to 34d is obtained using the thermal circuit network model in which the heat transfer paths Ka to Kd for each battery body 34a to 34d constituting the battery assembly 31 are constructed. T1 to T4 have been calculated, but the temperature of the battery main body 34 is changed using a thermal circuit model in which the heat transfer path of at least one of the battery main bodies 34a to 34d is constructed. May be detected only.

  (6) In the above embodiment, the temperatures T1 and T2 of the battery bodies 34a and 34b are calculated using the thermal circuit network model in which the heat transfer paths Ka and Kb are constructed for the battery bodies 34a and 34b, respectively. However, this may be changed. For example, a thermal circuit model in which one heat transfer path (specifically, one heat transfer path not having a branched path portion) through which heat generated in two battery main bodies 34a and 34b is transferred is created. You may calculate the temperature as each battery main body 34a, 34b whole using a thermal circuit model.

  In this case, the heat transfer path includes a tab path portion, a bus bar path portion K1c, and a substrate path portion K1d, and the tab path portion includes the electrode tabs 35 and 36 of the battery bodies 34a and 34b. Composed. The heat transfer resistance RT of the tab path portion is set as a combined resistance (RT = R13 · R14 / (R13 + R14)) of the heat transfer resistance R14 of the positive electrode tab 35 and the heat transfer resistance R13 of the negative electrode tab 36.

  In such a configuration, the heat transfer resistance RT of the tab path portion, the heat transfer resistance R15 of the bus bar path portion K1c (these correspond to the first heat transfer resistance), and the heat transfer resistance R20 (second heat transfer resistance) of the substrate path portion K1d. The temperature of the battery bodies 34a and 34b as a whole is calculated based on the above. Therefore, the calculated temperature can be acquired as, for example, the temperature of each battery body 34a, 34b.

  (7) In the above embodiment, when the heat generated in the battery body 34 is transmitted, the thermistors 51 and 52 (first temperature sensor) and the thermistor 53 (second temperature sensor) are transmitted by the same heat transfer path. Although it is assumed that heat is transferred to each, this may be changed, and the heat transfer paths to the thermistors (first temperature sensor, second temperature sensor) may be different.

  For example, as shown in FIG. 11, two heat transfer paths K11 and K12 are assumed in the battery main body 34, and the first temperature sensor is located at a position where the path length is L1 in one heat transfer path K11. S1 is provided, and the second heat sensor S2 is provided in the other heat transfer path K12 at a position where the path length is L2 (> L1). In the heat transfer path K11, the first heat transfer resistance R51 exists in the first path portion between the battery body 34 and the first temperature sensor S1, and in the heat transfer path K12, the first temperature sensor S1 and A second heat transfer resistance R52 exists in the second path portion between the second temperature sensors S2. The first heat transfer resistance R51 does not exist in the heat transfer path K12 here, but the first heat transfer resistance R51 virtually exists in the heat transfer path K12 at a position equivalent to the heat transfer path K11. As a result, a thermal network model is constructed.

  In such a case, the control unit 60 determines that the temperature difference between the sensors, which is the difference between the detected temperatures of the first temperature sensor S1 and the second temperature sensor S2, and the first heat transfer resistance R51 and the second heat transfer resistance R52, as described above. Based on this, the estimated temperature difference, which is the difference between the temperature of the battery body 34 and the first temperature sensor S1, is calculated, and the estimated temperature difference is added to the detected temperature of the first temperature sensor S1 to obtain the temperature of the battery body 34. calculate.

  (8) For example, the following modifications may be added to the thermal circuit network model of the above embodiment.

  In the battery unit 10 described above, it is assumed that heat is transferred (transferred) between the unit cells 33 (battery main bodies 34) adjacent to each other in the vertical direction. Therefore, a thermal circuit model considering this point may be created. For example, it is conceivable to create a thermal circuit model in which a heat transfer resistance is set between adjacent battery bodies 34.

  In the battery unit 10 described above, not only the bus bars 44d and 44e (46d and 46e) but also other bus bars 44a to 44c (46a to 46c) are connected to the control board 12. Therefore, the heat generated in the battery main body 34 is not only transmitted to the control board 12 via the bus bars 44d and 44e (46d and 46e), but also the control board 12 via these bus bars 44a to 44c (46a to 46c). Is transmitted to. Therefore, a thermal circuit model considering this point may be created.

  (9) In the above embodiment, the thermistors 51 and 52 are used as the temperature sensors. However, other temperature sensors such as a temperature sensitive diode may be used.

  (10) In the above embodiment, the present invention is applied to the battery assembly 31 (corresponding to an assembled battery) having a plurality of laminate-type single cells 33 (battery main body 34). The present invention may be applied to an assembled battery having a single cell. Further, the present invention is not necessarily applied to the assembled battery, and may be applied to, for example, a single storage battery.

  Moreover, in the said embodiment, although the lithium ion storage battery was used as the cell 33 (storage battery), you may use other storage batteries, such as a nickel-cadmium storage battery and a nickel hydride storage battery.

  DESCRIPTION OF SYMBOLS 10 ... Battery unit, 11 ... Assembly battery module, 12 ... Control board, 13 ... Housing case, 31 ... Battery assembly, 33 ... Single cell, 44 ... Bus bar, 46 ... Bus bar, 51 ... Thermistor, 52 ... Thermistor, 53 ... Thermistor.

Claims (7)

A first temperature sensor (51, 52) and a second temperature are located on a heat transfer path through which heat generated in the battery (34) is transferred, and the heat transfer path length from the battery is small and large. A battery temperature estimation device (60) that is applied to a battery unit (10) provided with a sensor (53) and estimates the temperature of the battery,
In the heat transfer path, there is a first heat transfer resistance (R13, R14, R15, R33, R34, R35) in a first path portion between the battery and the first temperature sensor, and the first temperature. A second heat transfer resistance (R20, R40) exists in a second path portion between the sensor and the second temperature sensor, and heat generated in the battery in the heat transfer path reduces the heat transfer resistance. Via the first temperature sensor and the second temperature sensor,
The battery and the first temperature sensor are based on a temperature difference between sensors, which is a difference between detected temperatures of the first temperature sensor and the second temperature sensor, and the first heat transfer resistance and the second heat transfer resistance. Temperature difference calculating means for calculating an estimated temperature difference that is a temperature difference between
Battery temperature calculating means for calculating the temperature of the battery by adding the estimated temperature difference calculated by the temperature difference calculating means to the temperature detected by the first temperature sensor;
With
The battery unit includes a control board (12), and the battery and the control board are electrically connected by conductive members (44, 46).
The first temperature sensor detects a temperature of a connection portion where the conductive member and the control board are connected,
The second temperature sensor detects a temperature of a part of the control board that is separated from the connection part,
The first path portion is configured to include the conductive member,
The second path portion includes the control board,
The first path portion includes a heat transfer resistance (R11) in the conductive member as the first heat transfer resistance,
The second path portion includes a heat transfer resistance (R20) in the control board as the second heat transfer resistance,
The temperature difference calculating means calculates the estimated temperature difference based on the heat transfer resistance in the conductive member and the heat transfer resistance in the control board ,
A plurality of the batteries, and the conductive members are connected to the batteries different from each other;
The heat transfer path is formed for each of the conductive members, and in each of the heat transfer paths, the first temperature sensor is provided for each path, and the second temperature sensor is provided for the common path,
The temperature difference calculating means calculates the estimated temperature difference in each of the plurality of heat transfer paths,
The battery temperature calculation unit is configured to calculate the battery temperature by adding the estimated temperature difference to the detected temperature of the first temperature sensor in each of the plurality of heat transfer paths. . The first temperature sensor and the second temperature sensor are provided at positions separated from each other on the control board,
In the first path portion, as the first heat transfer resistance, a heat transfer resistance in the conductive member and a heat transfer resistance in a separated portion from the connection portion of the conductive member to the first temperature sensor in the control board ( R12) and
The battery temperature estimation device according to claim 1, wherein the temperature difference calculation means calculates the estimated temperature difference based on the heat transfer resistances of the first path part. A first temperature sensor (51, 52) and a second temperature are located on a heat transfer path through which heat generated in the battery (34) is transferred, and the heat transfer path length from the battery is small and large. A battery temperature estimation device (60) that is applied to a battery unit (10) provided with a sensor (53) and estimates the temperature of the battery,
In the heat transfer path, there is a first heat transfer resistance (R13, R14, R15, R33, R34, R35) in a first path portion between the battery and the first temperature sensor, and the first temperature. A second heat transfer resistance (R20, R40) exists in a second path portion between the sensor and the second temperature sensor, and heat generated in the battery in the heat transfer path reduces the heat transfer resistance. Via the first temperature sensor and the second temperature sensor,
The battery and the first temperature sensor are based on a temperature difference between sensors, which is a difference between detected temperatures of the first temperature sensor and the second temperature sensor, and the first heat transfer resistance and the second heat transfer resistance. Temperature difference calculating means for calculating an estimated temperature difference that is a temperature difference between
Battery temperature calculating means for calculating the temperature of the battery by adding the estimated temperature difference calculated by the temperature difference calculating means to the temperature detected by the first temperature sensor;
With
A plurality of the batteries, and conductive members (44, 46) are connected to the batteries different from each other,
Wherein said heat transfer path is formed in each conductive member, the each of these heat transfer path, the first temperature sensor with provided for each path, and the second temperature sensor is provided in a path common,
The temperature difference calculating means calculates the estimated temperature difference in each of the plurality of heat transfer paths,
The battery temperature calculation unit is configured to calculate the battery temperature by adding the estimated temperature difference to the detected temperature of the first temperature sensor in each of the plurality of heat transfer paths. . A plurality of the batteries connected in series with each other;
Each of the plurality of batteries is provided with a positive electrode (35) and a negative electrode (36), and a positive electrode of one battery and a negative electrode of the other battery are adjacent to each other in series connection. Connected, the conductive member is connected to the connecting portion,
As the heat transfer path, there is a first heat transfer path through which heat of the one battery is transferred and a second heat transfer path through which heat of the other battery is transferred,
In the first heat transfer path, the first path portion includes the positive electrode and the conductive member,
In the second heat transfer path, the first path portion includes the negative electrode and the conductive member,
The first path portion of the first heat transfer path includes the heat transfer resistance (R13) in the positive electrode and the heat transfer resistance (R11) in the conductive member as the first heat transfer resistance. And
The first path portion of the second heat transfer path includes the heat transfer resistance (R14) in the negative electrode and the heat transfer resistance (R11) in the conductive member as the first heat transfer resistance. And
As the temperature difference calculating means, first temperature difference calculating means for calculating the estimated temperature difference in the first heat transfer path, and second temperature difference calculating means for calculating the estimated temperature difference in the second heat transfer path; Have
The first temperature difference calculating means calculates the estimated temperature difference of the first heat transfer path based on the heat transfer resistance in the positive electrode,
The second temperature difference calculating means calculates the estimated temperature difference of the second heat transfer path based on the heat transfer resistance in the negative electrode,
The battery temperature calculating means in each of said first heat transfer path and the second heat transfer path, said by adding the estimated temperature difference to the detected temperature of the first temperature sensor for calculating the temperature of each battery battery temperature estimation apparatus according to any one of claims 1 to 3, wherein. A first temperature sensor (51, 52) and a second temperature are located on a heat transfer path through which heat generated in the battery (34) is transferred, and the heat transfer path length from the battery is small and large. A battery temperature estimation device (60) that is applied to a battery unit (10) provided with a sensor (53) and estimates the temperature of the battery,
In the heat transfer path, there is a first heat transfer resistance (R13, R14, R15, R33, R34, R35) in a first path portion between the battery and the first temperature sensor, and the first temperature. A second heat transfer resistance (R20, R40) exists in a second path portion between the sensor and the second temperature sensor, and heat generated in the battery in the heat transfer path reduces the heat transfer resistance. Via the first temperature sensor and the second temperature sensor,
The battery and the first temperature sensor are based on a temperature difference between sensors, which is a difference between detected temperatures of the first temperature sensor and the second temperature sensor, and the first heat transfer resistance and the second heat transfer resistance. Temperature difference calculating means for calculating an estimated temperature difference that is a temperature difference between
Battery temperature calculating means for calculating the temperature of the battery by adding the estimated temperature difference calculated by the temperature difference calculating means to the temperature detected by the first temperature sensor;
With
The battery unit includes a control board (12), and the battery and the control board are electrically connected by conductive members (44, 46).
The first temperature sensor detects a temperature of a connection portion where the conductive member and the control board are connected,
The second temperature sensor detects a temperature of a part of the control board that is separated from the connection part,
The first path portion is configured to include the conductive member,
The second path portion includes the control board,
The first path portion includes a heat transfer resistance (R11) in the conductive member as the first heat transfer resistance,
The second path portion includes a heat transfer resistance (R20) in the control board as the second heat transfer resistance,
The temperature difference calculating means calculates the estimated temperature difference based on the heat transfer resistance in the conductive member and the heat transfer resistance in the control board,
A plurality of the batteries connected in series with each other;
Each of the plurality of batteries is provided with a positive electrode (35) and a negative electrode (36), and a positive electrode of one battery and a negative electrode of the other battery are adjacent to each other in series connection. Connected, the conductive member is connected to the connecting portion,
As the heat transfer path, there is a first heat transfer path through which heat of the one battery is transferred and a second heat transfer path through which heat of the other battery is transferred,
In the first heat transfer path, the first path portion includes the positive electrode and the conductive member,
In the second heat transfer path, the first path portion includes the negative electrode and the conductive member,
The first path portion of the first heat transfer path includes the heat transfer resistance (R13) in the positive electrode and the heat transfer resistance (R11) in the conductive member as the first heat transfer resistance. And
The first path portion of the second heat transfer path includes the heat transfer resistance (R14) in the negative electrode and the heat transfer resistance (R11) in the conductive member as the first heat transfer resistance. And
As the temperature difference calculating means, first temperature difference calculating means for calculating the estimated temperature difference in the first heat transfer path, and second temperature difference calculating means for calculating the estimated temperature difference in the second heat transfer path; Have
The first temperature difference calculating means calculates the estimated temperature difference of the first heat transfer path based on the heat transfer resistance in the positive electrode,
The second temperature difference calculating means calculates the estimated temperature difference of the second heat transfer path based on the heat transfer resistance in the negative electrode,
The battery temperature calculation means calculates the temperature of each battery by adding the estimated temperature difference to the temperature detected by the first temperature sensor in each of the first heat transfer path and the second heat transfer path. A battery temperature estimation device characterized by the above. A first temperature sensor (51, 52) and a second temperature are located on a heat transfer path through which heat generated in the battery (34) is transferred, and the heat transfer path length from the battery is small and large. A battery temperature estimation device (60) that is applied to a battery unit (10) provided with a sensor (53) and estimates the temperature of the battery,
In the heat transfer path, there is a first heat transfer resistance (R13, R14, R15, R33, R34, R35) in a first path portion between the battery and the first temperature sensor, and the first temperature. A second heat transfer resistance (R20, R40) exists in a second path portion between the sensor and the second temperature sensor, and heat generated in the battery in the heat transfer path reduces the heat transfer resistance. Via the first temperature sensor and the second temperature sensor,
The battery and the first temperature sensor are based on a temperature difference between sensors, which is a difference between detected temperatures of the first temperature sensor and the second temperature sensor, and the first heat transfer resistance and the second heat transfer resistance. Temperature difference calculating means for calculating an estimated temperature difference that is a temperature difference between
Battery temperature calculating means for calculating the temperature of the battery by adding the estimated temperature difference calculated by the temperature difference calculating means to the temperature detected by the first temperature sensor;
With
A plurality of the batteries connected in series with each other;
Each of the plurality of batteries is provided with a positive electrode (35) and a negative electrode (36), and a positive electrode of one battery and a negative electrode of the other battery are adjacent to each other in series connection. Connected, and the conductive member (44, 46) is connected to the connection part,
As the heat transfer path, there is a first heat transfer path through which heat of the one battery is transferred and a second heat transfer path through which heat of the other battery is transferred,
In the first heat transfer path, the first path portion includes the positive electrode and the conductive member,
In the second heat transfer path, the first path portion includes the negative electrode and the conductive member,
The first path portion of the first heat transfer path includes the heat transfer resistance (R13) in the positive electrode and the heat transfer resistance (R11) in the conductive member as the first heat transfer resistance. And
The first path portion of the second heat transfer path includes the heat transfer resistance (R14) in the negative electrode and the heat transfer resistance (R11) in the conductive member as the first heat transfer resistance. And
As the temperature difference calculating means, first temperature difference calculating means for calculating the estimated temperature difference in the first heat transfer path, and second temperature difference calculating means for calculating the estimated temperature difference in the second heat transfer path; Have
The first temperature difference calculating means calculates the estimated temperature difference of the first heat transfer path based on the heat transfer resistance in the positive electrode,
The second temperature difference calculating means calculates the estimated temperature difference of the second heat transfer path based on the heat transfer resistance in the negative electrode,
The battery temperature calculating means in each of said first heat transfer path and the second heat transfer path, said by adding the estimated temperature difference to the detected temperature of the first temperature sensor for calculating the temperature of each battery A battery temperature estimation device characterized by the above.   The battery temperature estimation device according to any one of claims 1 to 6, wherein the battery has a plate shape and a plurality of stacked batteries to form an assembled battery (31).

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