Battery measuring device

Abstract

A battery measuring device (50) includes a signal control section (56) provided on a first electrical path (81) connecting a positive electrode and a negative electrode of a storage battery (42) to output a prescribed alternating current signal from the storage battery, a response signal input section (50a) provided on a second electrical path (82) connecting the positive electrode and the negative electrode and inputting a response signal of the storage battery to the alternating current signal via the second electrical path, and a calculation section (53) calculating information related to complex impedance of the storage battery based on the response signal. A magnetic flux passing region (S10) through which magnetic flux generated based on the alternating current signal flowing through the first electrical path passes is formed as a region surrounded by the storage battery and the second electrical path. The size of the magnetic flux passing region is set so that an error of actual complex impedance of the storage battery and complex impedance calculated by the calculation section is within a range of ±1 mΩ.

Description

Technical Field

[0001] The present disclosure relates to a battery measurement device. Background Art

[0002] Conventionally, the battery's complex impedance has been measured to determine its condition (e.g., Patent Document 1). Patent Document 1 discloses a method in which a power controller applies a rectangular wave signal to the battery and calculates the complex impedance characteristics based on the response signal. The battery's deterioration status, for example, is determined based on this complex impedance characteristic.

[0003] In Patent Document 2, a sinusoidal current is passed from an oscillator to a battery, and its response signal (voltage fluctuation) is detected by a lock-in amplifier. Based on the detection result, a complex impedance characteristic is calculated. Furthermore, the degradation state of the battery is determined based on this complex impedance characteristic.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 6226261

[0007] Patent Document 2: Japanese Patent Application Publication No. 2018-190502 Summary of the Invention

[0008] However, batteries used in electric vehicles and other applications tend to have larger capacities. With larger capacities, the impedance decreases, making the response signal weak. Furthermore, a weak response signal is susceptible to external influences. For example, when an AC signal, such as a rectangular wave signal, is passed through the battery, the changes in magnetic flux caused by this AC signal generate an induced electromotive force in the electrical path used to input and output the response signal. Because the response signal is extremely weak, it is also affected by this induced electromotive force, leading to measurement errors.

[0009] The present disclosure has been made in view of the above-mentioned technical problems, and an object of the present disclosure is to provide a battery measuring device capable of improving the measurement accuracy of a response signal.

[0010] A first method for solving the above technical problem is a battery measuring device, which measures the state of a storage battery. The storage battery includes an electrolyte, a plurality of electrodes, and a housing for housing the electrolyte and the plurality of electrodes. The battery measuring device includes: a signal control unit, which is provided on a first electrical path connecting the positive electrode and the negative electrode of the storage battery and outputs a predetermined AC signal from the storage battery or inputs a predetermined AC signal to the storage battery; and a response signal input unit, which is provided on a second electrical path connecting the positive electrode and the negative electrode. a second electrical path, and inputting a response signal of the battery to the AC signal via the second electrical path; and a calculation unit, the calculation unit calculating information related to the complex impedance of the battery based on the response signal, wherein the battery measuring device forms a magnetic flux passage area, the magnetic flux passage area being an area surrounded by the battery and the second electrical path and being an area through which magnetic flux generated by the AC signal flowing through the first electrical path passes, the size of the magnetic flux passage area being set so that the error between the actual complex impedance of the battery and the complex impedance calculated by the calculation unit is within a range of ±1 mΩ.

[0011] The magnetic flux passage area enclosed by the battery and the second electrical path is set so that the error between the actual complex impedance of the battery and the complex impedance calculated by the calculation unit is within a range of ±1 mΩ. This suppresses errors in the response signal generated by the induced electromotive force and also reduces errors in the impedance.

[0012] The second aspect is a battery measuring device that measures a state of a storage battery including an electrolyte, a plurality of electrodes, and a housing case that houses the electrolyte and the plurality of electrodes, the battery measuring device including: a signal control portion that is provided on a first electrical path that connects a positive electrode-side power terminal and a negative electrode-side power terminal of the storage battery, and that causes a predetermined alternating-current signal to be output from or input to the storage battery; a response signal input portion that is provided on a second electrical path that connects the positive electrode-side power terminal and the negative electrode-side power terminal, and that inputs a response signal of the storage battery with respect to the alternating-current signal via the second electrical path; and a calculation portion that calculates a complex impedance of the storage battery on the basis of the response signal, the battery measuring device being formed with a magnetic flux passing region that is a region surrounded by the housing case, the second electrical path, the positive electrode-side power terminal, and the negative electrode-side power terminal, and that is a region through which a magnetic flux generated on the basis of the alternating-current signal flowing through the first electrical path passes, and the size of the magnetic flux passing region being set in such a manner that an induced electromotive force generated in the second electrical path on the basis of the alternating-current signal flowing through the first electrical path is within an electromotive force allowable value range that includes zero.

[0013] The size of the induced electromotive force generated on the basis of the alternating-current signal and the polarity thereof can be changed by the magnetic flux passing region surrounded by the housing case, the second electrical path, the positive electrode-side power terminal, and the negative electrode-side power terminal. Therefore, by appropriately setting the size of the magnetic flux passing region, the induced electromotive force is within the electromotive force allowable value range that includes zero. Also, similarly, the induced electromotive force based on an external signal such as noise from an inverter can be reduced. Thus, the error of the response signal generated on the basis of the induced electromotive force can be suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0014] The above objects, other objects, features, and advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0015] Figure 1 is a schematic configuration diagram of a power supply system.

[0016] Figure 2 (a) of FIG. 1 is a perspective view showing a battery cell, and (b) is a plan view showing a battery pack.

[0017] Figure 3 is a configuration diagram of a battery measuring device.

[0018] Figure 4 is a flowchart of an impedance calculation process.

[0019] Figure 5 It is a side view showing the connection method of the battery measuring device in the comparative example.

[0020] Figure 6 This is a circuit diagram of a battery measuring device.

[0021] Figure 7 It is a side view schematically showing the connection method of the battery measuring device in the first embodiment.

[0022] Figure 8 It is a side view schematically showing the connection method of the battery measuring device in the second embodiment.

[0023] Figure 9 It is a side view schematically showing the connection method of the battery measuring device in the third embodiment.

[0024] Figure 10 It is a plan view showing a battery measuring device in a fourth embodiment.

[0025] Figure 11 It is a side view schematically showing the connection method of the battery measuring device in the fourth embodiment.

[0026] Figure 12 It is a plan view schematically showing the connection method of the battery measuring device in the fifth embodiment.

[0027] Figure 13 It is a side view showing a battery measuring device in the sixth embodiment.

[0028] Figure 14 It is a side view showing a battery measuring device in the seventh embodiment.

[0029] Figure 15 It is a side view showing a battery measuring device in the eighth embodiment.

[0030] Figure 16 It is a perspective view showing a shielding member.

[0031] Figure 17 (a) is a side view of the circuit board and the battery cell in the ninth embodiment, and (b) is a cross-sectional view of the cylindrical portion.

[0032] Figure 18 FIG1 is a diagram showing the configuration of a battery measuring device according to a tenth embodiment.

[0033] Figure 19 This is a flowchart of the impedance calculation process in the tenth embodiment.

[0034] Figure 20 This is a structural diagram of another example of a battery measuring device.

[0035] Figure 21 This is a structural diagram of another example of a battery measuring device.

[0036] Figure 22 This is a structural diagram of another example of a battery measuring device.

[0037] Figure 23 This is a structural diagram of another example of a battery cell.

[0038] Figure 24 This is a structural diagram of another example of a battery cell.

[0039] Figure 25 This is a structural diagram of another example of a battery measuring device.

[0040] Figure 26 It is a perspective view showing the structure of another example of a shield member.

[0041] Figure 27 This is an explanatory diagram showing the relationship between impedance measurement accuracy and battery capacity.

[0042] Figure 28 (a) is a perspective view showing a battery cell according to Modification 1, and (b) is a perspective view showing a battery pack according to Modification 1.

[0043] Figure 29 It is a perspective view schematically showing the connection method of a battery measuring device in a comparative example.

[0044] Figure 30 This is a perspective view schematically showing the connection method of the battery measuring device in Modification 1.

[0045] Figure 31 This is a perspective view schematically showing the connection method of the battery measuring device in Modification 2.

[0046] Figure 32 This is a perspective view schematically showing a battery pack and a circuit board in Modification 3.

[0047] Figure 33 (a) is a plan view showing a portion of a circuit board in Modification 3, and (b) is a side view showing a battery cell and a circuit board in Modification 3.

[0048] Figure 34 (a) is a top view of a portion of the circuit substrate in variant example 3, (b) is a side view of the battery cells and circuit substrate in the first column, (c) is a side view of the battery cells and circuit substrate in the second column, and (d) is a top view of a portion of the circuit substrate in variant example 3.

[0049] Figure 35(a) is a top view showing the busbar of Modification 3, and (b) is a side view showing the busbar of Modification 3.

[0050] Figure 36 (a) is a plan view showing a portion of a circuit board in another example of Modification 3, and (b) is a plan view showing a bus bar in another example of Modification 3.

[0051] Figure 37 This is a structural diagram of another example of a battery measuring device. DETAILED DESCRIPTION

[0052] (First embodiment)

[0053] Hereinafter, a first embodiment in which a “battery measuring device” is applied to a power supply system of a vehicle (eg, a hybrid vehicle or an electric vehicle) will be described with reference to the drawings.

[0054] like Figure 1 As shown, the power supply system 10 includes: an electric motor 20 as a rotating electrical machine; an inverter 30 as a power converter for passing a three-phase current through the electric motor 20; a battery pack 40 that can be charged and discharged; a battery measuring device 50 for measuring the state of the battery pack 40; and an ECU 60 that controls the electric motor 20 and the like.

[0055] The electric motor 20 is a vehicle-mounted main unit capable of transmitting power to drive wheels (not shown). In this embodiment, a three-phase permanent magnet synchronous motor is used as the electric motor 20 .

[0056] The inverter 30 is composed of a full-bridge circuit having upper and lower arms, the number of which is equal to the number of phases of the phase windings. The current flowing through each phase winding is adjusted by turning on and off a switch (semiconductor switching element) provided in each arm.

[0057] The inverter 30 is equipped with an inverter control device (not shown). The inverter control device controls power supply by turning on and off various switches in the inverter 30 based on various detection information from the motor 20 and requests for power operation and power generation. As a result, the inverter control device supplies power from the battery pack 40 through the inverter 30 to the motor 20, causing the motor 20 to perform power operation. Furthermore, the inverter control device generates power from the motor 20 based on the power from the drive wheels, converts the generated power through the inverter 30, and supplies it to the battery pack 40, thereby charging the battery pack 40.

[0058] The battery pack 40 is electrically connected to the electric motor 20 via the inverter 30. The battery pack 40 has, for example, a terminal voltage of 100 V or higher and is composed of a plurality of battery modules 41 connected in series. The battery modules 41 are composed of a plurality of battery cells 42 connected in series. For example, lithium-ion batteries or nickel-metal hydride batteries can be used as the battery cells 42. Each battery cell 42 is a battery having an electrolyte and a plurality of electrodes.

[0059] like Figure 2 As shown in (a), the battery cell 42, and more specifically, its housing 42a, is formed into a flat rectangular parallelepiped shape, and power terminals 71 (positive side power terminal 71a and negative side power terminal 71b) are provided at both ends of the long side direction of its upper surface. The positive side power terminal 71a and the negative side power terminal 71b protrude from the housing 42a in the same direction and to the same extent. Figure 2 As shown in (b), the housing cases 42a of the battery cells 42 are stacked in the short-side direction with their side faces overlapping. At this time, the positive-side power supply terminals 71a and the negative-side power supply terminals 71b are arranged so as to be different from each other in adjacent battery cells 42 .

[0060] Then, to connect the battery cells 42 in series, the positive power supply terminal 71a of the battery cell 42 is connected to the negative power supply terminal 71b of the adjacent battery cell 42 via the bus bar 73. Furthermore, the negative power supply terminal 71b of the battery cell 42 is connected to the positive power supply terminal 71a of the other adjacent battery cell 42 via the bus bar 73.

[0061] The busbar 73 is made of a conductive material and is formed into a thin plate having a length that is sufficient for adjacent power terminals 71 to reach, for example, approximately two to three times the thickness of the battery cell 42 in the short-side direction. The busbar 73 is connected (eg, by welding) to each power terminal 71 so as to cover the outer end (outer half) of the power terminal 71 in the long-side direction of the battery cell 42.

[0062] like Figure 1 As shown, the positive-side power supply path L1, which is connected to the positive-side power supply terminal of the battery pack 40, is connected to the positive-side terminal of an electrical load such as the inverter 30. Similarly, the negative-side power supply path L2, which is connected to the negative-side power supply terminal of the battery pack 40, is connected to the negative-side terminal of an electrical load such as the inverter 30. Furthermore, a relay switch SMR (system main relay switch) is provided on each of the positive-side power supply path L1 and the negative-side power supply path L2, and the relay switch SMR is configured to switch between energization and de-energization.

[0063] The battery measuring device 50 measures the state of charge (SOC) and state of degradation (SOH) of each battery cell 42. In the first embodiment, the battery measuring device 50 is provided for each battery module 41. The battery measuring device 50 is connected to the ECU 60 and outputs the state of each battery cell 42. The structure of the battery measuring device 50 will be described in detail later.

[0064] The ECU 60 requests the inverter control device to perform power running and power generation based on various information, such as information on accelerator and brake operation, vehicle speed, and the state of the battery pack 40.

[0065] Next, the battery measuring device 50 will be described in detail. Figure 3 As shown, in the first embodiment, a battery measuring device 50 is provided for each battery cell 42 .

[0066] The battery measuring device 50 includes an ASIC unit 50a, a filter unit 55, and a current modulation circuit 56. The ASIC unit 50a includes a stabilized power supply unit 51, an input / output unit 52, a microcomputer unit 53 as a calculation unit, and a communication unit 54.

[0067] The stabilized power supply unit 51 is connected to the power line of the battery unit 42 and supplies power from the battery unit 42 to the input / output unit 52, the microcomputer unit 53, and the communication unit 54. The input / output unit 52, the microcomputer unit 53, and the communication unit 54 are driven by this power.

[0068] The input / output unit 52 is connected to the battery cell 42, which is the object of measurement. Specifically, the input / output unit 52 includes a DC voltage input terminal 57 that can input (measure) a DC voltage from the battery cell 42. A filter unit 55 is provided between the battery cell 42 and the DC voltage input terminal 57. Specifically, an RC filter 55a serving as a filter circuit and a Zener diode 55b serving as a protective element are provided between the positive terminal 57a and the negative terminal 57b of the DC voltage input terminal 57. In other words, the RC filter 55a, Zener diode 55b, and other components are connected in parallel with the battery cell 42.

[0069] The input / output unit 52 also includes a response signal input terminal 58 for inputting a response signal (voltage fluctuation) reflecting the internal complex impedance information of the battery cell 42 between the terminals of the battery cell 42. Therefore, the input / output unit 52 functions as a response signal input unit.

[0070] Furthermore, the positive-side power terminal 71a and the negative-side power terminal 71b of the battery cell 42 are connected to the electrodes (positive or negative), respectively. Furthermore, it is desirable that the response signal input terminal 58 be connected to the portion of the positive-side power terminal 71a and the negative-side power terminal 71b that is closest to the electrodes, among the connectable portions. Similarly, the connection point of the DC voltage input terminal 57 is preferably the portion closest to the electrodes, or the portion close to the connection point of the response signal input terminal 58. This minimizes the effects of voltage drop caused by the main current or the balancing current.

[0071] The input / output unit 52 is connected to the current modulation circuit 56, which serves as a signal control unit, and includes an instruction signal output terminal 59a. The instruction signal output terminal 59a outputs an instruction signal to the current modulation circuit 56, indicating the sine wave signal (AC signal) output from the battery cell 42. The input / output unit 52 also includes a feedback signal input terminal 59b. The feedback signal input terminal 59b receives the current signal actually output (flowing) from the battery cell 42 via the current modulation circuit 56 as a feedback signal.

[0072] The input / output unit 52 is connected to the microcomputer unit 53 and is configured to output the DC voltage inputted from the DC voltage input terminal 57, the response signal inputted from the response signal input terminal 58, the feedback signal inputted from the feedback signal input terminal 59b, and the like to the microcomputer unit 53. Furthermore, the input / output unit 52 internally includes an AD converter and is configured to convert the input analog signal into a digital signal and output the digital signal to the microcomputer unit 53.

[0073] The input / output unit 52 is configured to receive an instruction signal from the microcomputer unit 53 and output the instruction signal from the instruction signal output terminal 59a to the current modulation circuit 56. The input / output unit 52 internally includes a DA converter, converts the digital signal input from the microcomputer unit 53 into an analog signal, and outputs the instruction signal to the current modulation circuit 56. A DC bias is applied to the sinusoidal wave signal directed to the current modulation circuit 56 by the instruction signal so that the sinusoidal wave signal does not become a negative current (which flows back to the battery cell 42).

[0074] The current modulation circuit 56 is a circuit that uses the battery cell 42, the object of measurement, as a power source to output a predetermined AC signal (sine wave signal). Specifically, the current modulation circuit 56 includes a semiconductor switch element 56a (e.g., a MOSFET) as a switching unit, and a resistor 56b connected in series with the semiconductor switch element 56a. The drain terminal of the semiconductor switch element 56a is connected to the positive power supply terminal 71a of the battery cell 42, and the source terminal of the semiconductor switch element 56a is connected in series with one end of the resistor 56b. In addition, the other end of the resistor 56b is connected to the negative power supply terminal 71b of the battery cell 42. The semiconductor switch element 56a is configured to be able to adjust the amount of current flowing between the drain terminal and the source terminal. In addition, in order to adjust the voltage applied to the semiconductor switch element 56a according to the operating range of the semiconductor switch element 56a, a resistor is sometimes inserted in series with the current modulation circuit.

[0075] Furthermore, the current modulation circuit 56 includes a current detection amplifier 56c as a current detection unit connected to both ends of the resistor 56b. The current detection amplifier 56c is configured to detect a signal (current signal) flowing through the resistor 56b and output the detection signal as a feedback signal to a feedback signal input terminal 59b of the input / output unit 52.

[0076] Furthermore, a feedback circuit 56d is provided in the current modulation circuit 56. The feedback circuit 56d is configured to receive an instruction signal from the instruction signal output terminal 59a of the input / output unit 52 and a feedback signal from the current detection amplifier 56c. The circuit 56d then compares the instruction signal with the feedback signal and outputs the result to the gate terminal of the semiconductor switch element 56a.

[0077] Based on a signal from feedback circuit 56d, semiconductor switch element 56a adjusts the voltage applied between the gate and source so that a sinusoidal signal (predetermined AC signal) indicated by the instruction signal is output from battery cell 42, thereby regulating the amount of current flowing between the drain and source. Furthermore, if an error occurs between the waveform indicated by the instruction signal and the waveform actually flowing through resistor 56b, semiconductor switch element 56a adjusts the current based on the signal from feedback circuit 56d to correct the error. This stabilizes the sinusoidal signal flowing through resistor 56b.

[0078] Next, a method for calculating the complex impedance of the battery cell 42 will be described. The battery measuring device 50 executes the calculation at every predetermined period. Figure 4 The impedance calculation process is shown.

[0079] In the impedance calculation process, the microcomputer unit 53 first sets a measurement frequency for the complex impedance (step S101). The measurement frequency is set from frequencies within a predetermined measurement range.

[0080] Next, the microcomputer 53 determines the frequency of the sinusoidal wave signal (predetermined alternating current signal) based on the measurement frequency, and outputs an instruction signal indicating the output of the sinusoidal wave signal to the input / output section 52 (step S102).

[0081] The input / output section 52, upon input of the instruction signal, converts it to an analog signal with a DA converter, and outputs it to the current modulation circuit 56. The current modulation circuit 56, based on the instruction signal, causes the sinusoidal wave signal to be output from the battery cell 42 as a power source. Specifically, the semiconductor switching element 56a adjusts the amount of current based on a signal input via the feedback circuit 56d, so that the sinusoidal wave signal indicated by the instruction signal is output from the battery cell 42. As a result, the sinusoidal wave signal is output from the battery cell 42.

[0082] Upon output of the sinusoidal wave signal from the battery cell 42, that is, upon application of external disturbance to the battery cell 42, a voltage variation reflecting internal complex impedance information of the battery cell 42 occurs between the terminals of the battery cell 42. The input / output section 52 inputs this voltage variation via the response signal input terminal 58, and outputs it as a response signal to the microcomputer 53. At this time, it is converted to a digital signal with an AD converter and output.

[0083] After executing step S102, the microcomputer 53 inputs the response signal from the input / output section 52 (step S103). Further, the microcomputer 53 acquires a signal flowing through the resistor 56b of the current modulation circuit 56 (that is, the alternating current signal output from the battery cell 42), as a current signal (step S104). Specifically, the microcomputer 53 inputs the feedback signal (detection signal) output from the current detection amplifier 56c via the input / output section 52 as the current signal. Alternatively, instead of the feedback signal, a value proportional to the instruction signal indicated to the current modulation circuit 56 can be used as the current signal.

[0084] Next, the microcomputer 53 calculates information related to the complex impedance of the battery cell 42 based on the response signal and the current signal (step S105). That is, the microcomputer 53 calculates all or any one of the absolute value of the complex impedance, the phase, based on the real part of the response signal, the imaginary part of the response signal, the real part of the current signal, and the imaginary part of the current signal. The microcomputer 53 outputs the calculation result to the ECU 60 via the communication section 54 (step S106). Then, the calculation processing ends.

[0085] This calculation processing is repeatedly executed until the complex impedance for a plurality of frequencies within the measurement range is calculated. The ECU 60, based on the calculation result, for example, creates a complex impedance plane plot (Cole-Cole plot), and thereby grasps the characteristics of the electrode and the electrolyte, etc. For example, the state of charge (SOC), the state of health (SOH) are grasped.

[0086] Furthermore, it is not necessary to create the entire Cole-Cole plot; a portion of the plot may be considered. For example, complex impedance at a specific frequency may be measured at regular intervals during driving, and changes in SOC, SOH, battery temperature, and the like during driving may be understood based on the temporal changes in the complex impedance at this specific frequency. Alternatively, complex impedance at a specific frequency may be measured at daily, weekly, or yearly intervals, and changes in SOH and the like may be understood based on the temporal changes in the complex impedance at this specific frequency.

[0087] Furthermore, when the current modulation circuit 56 outputs an AC signal (such as a sine wave signal) from the battery cell 42 via the first electrical path 81, an induced electromotive force based on the AC signal is generated in the second electrical path 82. Because the response signal is extremely weak, the generation of an induced electromotive force based on the AC signal in the second electrical path 82 can cause measurement errors. Therefore, the battery measuring device 50 is configured to reduce the induced electromotive force.

[0088] Here, before describing the structure for reducing the induced electromotive force, the principle of generation of the induced electromotive force and the principle for suppressing the induced electromotive force will be described. Figure 5 1 and 2 are diagrams showing a general model of the first electric path 81 , the second electric path 82 , and the electric path (current path) within the battery cell 42 . Figure 6 2 is a circuit diagram schematically showing the circuit configuration of the battery measuring device 50 .

[0089] Mathematical formula (1) represents Faraday's law. In addition, "E(x, t)" represents the electric field vector, and "L" represents the path of the line integral. "B(x, t)" represents the magnetic flux density vector. "S" represents the partially enclosed area surrounded by the path of the line integral on the left. "n" represents the normal vector of the point on "S". "x" is a vector representing the position from the current sheet, and "t" represents time. That is, the electric field vector "E(x, t)" and the magnetic flux density vector "B(x, t)" are values ​​that depend on the place and time. "Vi(t)" represents the induced electromotive force.

[0090] In the first embodiment, "E(x, t)" represents the electric field vector in the second electrical path 82, and "L" represents the path of the second electrical path 82. "B(x, t)" represents the magnetic flux density vector passing through the area surrounded by the second electrical path 82, the power supply terminal 71, and the housing 42a (the magnetic flux passage area S10). "S" represents the surface of the magnetic flux passage area S10. "x" is a vector indicating the position from the current element set in the first electrical path 81. "Vi(t)" represents the induced electromotive force generated in the second electrical path 82.

[0091] [Mathematical formula 1]

[0092]

[0093] According to Faraday's law, the induced electromotive force can be reduced by reducing the magnetic flux passing area S10 surrounded by the second electrical path 82 etc. Furthermore, it can be seen that the induced electromotive force can be reduced by increasing the distance from the first electrical path 81 .

[0094] However, if Figure 5 As shown, the battery cell 42 needs to be structurally provided with a positive-side power supply terminal 71a and a negative-side power supply terminal 71b. Therefore, the second electrical path 82 needs to be branched midway between the second electrical path A 82a, which connects the ASIC unit 50a to the positive-side power supply terminal 71a and serves as a positive-side detection line (conducting wire), and the second electrical path B 82b, which connects the ASIC unit 50a to the negative-side power supply terminal 71b and serves as a negative-side detection line (conducting wire).

[0095] Therefore, if Figure 5 With the second electrical path 82 configured as shown, the area enclosed by the housing case 42a, the second electrical path 82, the positive-side power terminal 71a, and the negative-side power terminal 71b is larger. This area becomes the magnetic flux passage area S10, through which the magnetic flux of the AC signal I flowing through the first electrical path 81 passes. Furthermore, similarly to the second electrical path 82, there are limitations on increasing the distance between the first electrical path 81 and the second electrical path 82 in order to facilitate connection between the first electrical path 81 and the positive-side power terminal 71a and the negative-side power terminal 71b.

[0096] Therefore, the following structure is formed so as to reduce the size of the magnetic flux passing region S10 as much as possible. Figure 7 FIG is a side view schematically showing how the battery measuring device 50 in this embodiment is connected to the battery cell 42. Figure 7 As shown, the second A electrical path 82a connected to the ASIC unit 50a is routed along the second B electrical path 82b to a predetermined branch point Br1. That is, the second A electrical path 82a and the second B electrical path 82b are routed in parallel with as little gap as possible. Figure 7In the figure, the second electrical path 82 from the ASIC part 50a to the branch point Br1 is wired along the protruding direction of the power terminal 71, but as long as the second A electrical path 82a and the second B electrical path 82b are wired along, they can be wired in any way. For example, they can be wired along the short side direction of the battery cell 42 (vertical direction of the paper). In addition, when the second A electrical path 82a and the second B electrical path 82b are wired along, they do not need to be wired in a straight line, and they can be bent arbitrarily as long as they are bent in the same way. In addition, the second A electrical path 82a and the second B electrical path 82b are respectively covered by an insulating film. Alternatively, a minimum gap that can ensure the degree of insulation can be set between the second A electrical path 82a and the second B electrical path 82b.

[0097] Then, the second A electrical path 82a is routed from the branch point Br1 toward the positive-side power supply terminal 71a, while the second B electrical path 82b is routed from the branch point Br1 toward the negative-side power supply terminal 71b. "From the branch point Br1 toward the power supply terminal 71" means, for example, that the inner product of the vector indicating the direction of current flow after the branch point and the vector from the branch point to an arbitrary point on the electrode, projected onto a plane containing the top surface of the electrode, is positive.

[0098] Furthermore, the branch point Br1 is located between the front ends of the positive and negative power terminals 71a, 71b and the housing 42a, in the direction in which the positive and negative power terminals 71a, 71b protrude. More specifically, the branch point Br1 is located at a position abutting the housing 42a. Furthermore, the branch point Br1 is located between the positive and negative power terminals 71a, 71b, in the direction of the short sides of the battery cell 42.

[0099] In addition, Figure 7 In the embodiment, the position of the branch point Br1 is positioned at the center of the positive power terminal 71a and the negative power terminal 71b in the longitudinal direction of the battery cell 42. However, the position can be changed arbitrarily as long as it is between the positive power terminal 71a and the negative power terminal 71b. Furthermore, when the branch point Br1 is positioned at the positive power terminal 71a, only the second B electrical path 82b is routed from the branch point Br1 toward the negative power terminal 71b. Similarly, when the branch point Br1 is positioned at the negative power terminal 71b, only the second A electrical path 82a is routed from the branch point Br1 toward the positive power terminal 71a.

[0100] Then, the second A electrical path 82a is wired in a straight line along the outer peripheral surface of the containment shell 42a from the branch point Br1 toward the positive side power terminal 71a. On the other hand, the second B electrical path 82b is wired in a straight line along the outer peripheral surface of the containment shell 42a from the branch point Br1 toward the negative side power terminal 71b. In addition, the second A electrical path 82a and the second B electrical path 82b are in contact with the containment shell 42a via an insulating member not shown in the figure to ensure insulation relative to the containment shell 42a. The insulating member can be an insulating film that covers the second A electrical path 82a and the second B electrical path 82b, or it can be a circuit substrate, etc. Alternatively, a minimum gap that can ensure the degree of insulation can be set between the second electrical path 82 and the containment shell 42a.

[0101] According to the first embodiment, the following effects are achieved.

[0102] The area surrounded by the housing 42a, the second electrical path 82, the positive-side power supply terminal 71a, and the negative-side power supply terminal 71b constitutes a magnetic flux passage area S10, through which magnetic flux based on the AC signal I flowing through the first electrical path 81 passes. Furthermore, the magnetic flux passage area S10 also passes through a magnetic flux based on external signals, such as noise from the inverter 30. The magnitude of the induced electromotive force generated in the second electrical path 82 corresponds to the magnitude of the magnetic flux in this magnetic flux passage area S10 (more precisely, the magnitude of the temporal variation of the magnetic flux). Therefore, the size of the magnetic flux passage area S10 is set so that the induced electromotive force generated in the second electrical path 82 is within the permissible electromotive force value range that includes zero.

[0103] Specifically, the second electrical path A 82a is routed from the branch point Br1 toward the positive-side power terminal 71a, while the second electrical path B 82b is routed from the branch point Br1 toward the negative-side power terminal 71b. The branch point Br1 is positioned between the front ends of the positive-side power terminal 71a and the negative-side power terminal 71b and the housing 42a.

[0104] More specifically, the branch point Br1 is positioned so as to abut against the housing case 42a. The second electrical path A 82a is routed from the branch point Br1 toward the positive-side power supply terminal 71a along the outer circumference of the housing case 42a. Furthermore, the second electrical path B 82b is routed from the branch point Br1 toward the negative-side power supply terminal 71b along the outer circumference of the housing case 42a.

[0105] This minimizes the size of the magnetic flux passage area S10, thereby reducing errors in the response signal due to the induced electromotive force. Furthermore, the battery cell 42 can be flattened. Furthermore, by connecting the first electrical path 81 to the tip of the power terminal 71, the magnetic flux passage area S10 can be moved away from the first electrical path 81 connected to the tip of the power terminal 71, thus reducing errors in the response signal due to the induced electromotive force. Furthermore, it is desirable that the relative positions of the first electrical path 81 and the second electrical path 82 be fixed.

[0106] (Second embodiment)

[0107] Next, a battery measuring device 50 according to a second embodiment will be described. In the following, identical or equivalent components in each embodiment will be denoted by the same reference numerals, and the descriptions of the components with the same reference numerals will be cited. Furthermore, in this second embodiment, the structure of the first embodiment will be used as an example as the basic structure.

[0108] In the second embodiment, similarly to the first embodiment, Figure 8 As shown, the second A electrical path 82a connected to the ASIC unit 50a is routed along the second B electrical path 82b to a predetermined branch point Br2. The second A electrical path 82a is then routed to branch from the second B electrical path 82b at the branch point Br2.

[0109] The branch point Br2 of the second embodiment is not arranged between the front end position of the positive side power terminal 71a and the negative side power terminal 71b and the housing 42a in the protruding direction of the positive side power terminal 71a and the negative side power terminal 71b. In other words, the branch point Br2 is arranged at a position on the opposite side of the housing 42a than the front end position of the positive side power terminal 71a and the negative side power terminal 71b in the protruding direction of the power terminal 71. Figure 8 In the short-side direction of the battery cell 42 (vertical to the paper), the position of the branch point Br2 is set between the positive-side power supply terminal 71a and the negative-side power supply terminal 71b, but can be changed arbitrarily. In the long-side direction of the battery cell 42, the position of the branch point Br2 is set between the positive-side power supply terminal 71a and the negative-side power supply terminal 71b.

[0110] Furthermore, the second A electrical path 82a is routed so as to intersect the second B electrical path 82b once between the branch point Br2 and the positive-side power supply terminal 71a. Specifically, the second A electrical path 82a and the second B electrical path 82b temporarily separate, then approach and intersect, before being connected to each power supply terminal 71.

[0111] based on Figure 8To describe in detail, the second A electrical path 82a is wired in a manner that temporarily faces the negative-side power terminal 71b from the branching point Br2 and then faces the positive-side power terminal 71a. Similarly, the second B electrical path 82b is wired in a manner that temporarily faces the positive-side power terminal 71a from the branching point Br2 and then faces the negative-side power terminal 71b. The second A electrical path 82a crosses the second B electrical path 82b halfway toward the positive-side power terminal 71a.

[0112] Thus, the magnetic flux passing through the region S10 is divided into a first magnetic flux passing region S11 as a first region and a second magnetic flux passing region S12 as a second region. The first magnetic flux passing region S11 is a region surrounded by the second A electrical path 82a disposed on the positive-side power terminal 71a side more than the second B electrical path 82b and the second B electrical path 82b disposed on the negative-side power terminal 71b side more than the second A electrical path 82a. The first magnetic flux passing region S11 in the second embodiment can also be said to be a region surrounded by the second A electrical path 82a between the positive-side power terminal 71a and the crossing point Cr1, the second B electrical path 82b between the negative-side power terminal 71b and the crossing point Cr1, and the accommodation case 42a.

[0113] The second magnetic flux passing region S12 is a region surrounded by the second A electrical path 82a disposed on the negative-side power terminal 71b side more than the second B electrical path 82b and the second B electrical path 82b disposed on the positive-side power terminal 71a side more than the second A electrical path 82a. The second magnetic flux passing region S12 in the second embodiment can also be said to be a region surrounded by the second A electrical path 82a between the crossing point Cr1 and the branching point Br2 and the second B electrical path 82b between the crossing point Cr1 and the branching point Br1.

[0114] Also, in the first electrical path 81, in the case where the alternating-current signal I flows as shown in FIG. 6, the direction of the magnetic flux between the power terminals 71 becomes the front side from the paper surface side. At this time, the current flows in the direction of the first electrical path 81 due to the induced electromotive force as shown in FIG. 7 as the counterclockwise direction. Also, since the positional relationship of the second A electrical path 82a and the second B electrical path 82b is reversed with the crossing point Cr1 as a boundary, the phase of the induced electromotive force generated based on the magnetic flux passing through the first magnetic flux passing region S11 and the induced electromotive force generated based on the magnetic flux passing through the second magnetic flux passing region S12 is shifted by 180 degrees. That is, the induced electromotive forces are generated in a canceling manner. The same is true in the case where the flow direction of the alternating-current signal I is reversed. Figure 8 Figure 8 Also, in the first electrical path 81, in the case where the alternating-current signal I flows as shown in FIG. 6, the direction of the magnetic flux between the power terminals 71 becomes the front side from the paper surface side. At this time, the current flows in the direction of the first electrical path 81 due to the induced electromotive force as shown in FIG. 7 as the counterclockwise direction. Also, since the positional relationship of the second A electrical path 82a and the second B electrical path 82b is reversed with the crossing point Cr1 as a boundary, the phase of the induced electromotive force generated based on the magnetic flux passing through the first magnetic flux passing region S11 and the induced electromotive force generated based on the magnetic flux passing through the second magnetic flux passing region S12 is shifted by 180 degrees. That is, the induced electromotive forces are generated in a canceling manner. The same is true in the case where the flow direction of the alternating-current signal I is reversed.

[0115] ​Furthermore, the magnitude of the induced electromotive force depends on the magnitude of the magnetic flux passing through the first magnetic flux passage area S11 and the second magnetic flux passage area S12 (more precisely, the magnitude of the temporal change in the magnetic flux). Therefore, the size of the second magnetic flux passage area S12 is set based on the size of the first magnetic flux passage area S11 so that the difference between the first magnetic flux generated based on the AC signal I passing through the first magnetic flux passage area S11 and the second magnetic flux generated based on the AC signal I passing through the second magnetic flux passage area S12 is within the permissible magnetic flux value range that includes zero. In other words, the size of the second magnetic flux passage area S12 is set based on the size of the first magnetic flux passage area S11 so that the sum of the induced electromotive force generated based on the magnetic flux passing through the first magnetic flux passage area S11 and the induced electromotive force generated based on the magnetic flux passing through the second magnetic flux passage area S12 is within the permissible electromotive force value range.

[0116] For example, if the first magnetic flux passing area S11 and the second magnetic flux passing area S12 are on the same plane and are at the same distance from the first electrical path 81, then by setting the first magnetic flux passing area S11 and the second magnetic flux passing area S12 to the same size, the induced electromotive force can be within the allowable electromotive force value range.

[0117] The permissible magnetic flux value range can be arbitrarily set, taking into account the required calculation accuracy, the magnitude of the response signal, and the noise signal. Furthermore, the permissible electromotive force value range can be arbitrarily set, taking into account the required calculation accuracy, the magnitude of the response signal, and the noise signal. In this embodiment, the permissible electromotive force value range is set to ±200 μV centered on zero.

[0118] Thus, the sum of the induced electromotive force generated by the magnetic flux passing through the first magnetic flux passing area S11 and the induced electromotive force generated by the magnetic flux passing through the second magnetic flux passing area S12 is within the electromotive force allowable value range, and the error of the response signal based on the induced electromotive force can be suppressed.

[0119] (Third embodiment)

[0120] Next, a battery measuring device 50 according to a third embodiment will be described. In the following, identical or equivalent components in each embodiment will be denoted by the same reference numerals, and the descriptions of the components with the same reference numerals will be cited. Furthermore, in this third embodiment, the structure of the first embodiment will be used as an example as the basic structure.

[0121] In a third embodiment, if Figure 9As shown, the magnetic flux passage area S10 is covered by the first magnetic shield 101. In addition, at least a portion of the first electrical path 81 is covered by the second magnetic shield 102. The second magnetic shield 102 is provided on one side of the power supply terminal 71 and covers at least a portion of the power supply terminal 71.

[0122] The first magnetic shield 101 makes it difficult for magnetic flux based on the AC signal or external noise to pass through the magnetic flux passage region S10, thereby suppressing the generation of an induced electromotive force. Furthermore, the second magnetic shield 102 prevents magnetic flux based on the AC signal I from passing through the magnetic flux passage region S10, thereby suppressing the induced electromotive force.

[0123] Furthermore, in the third embodiment, both the first magnetic shield 101 and the second magnetic shield 102 are provided, but only one of them may be provided.

[0124] (Fourth embodiment)

[0125] Next, a battery measuring device 50 according to a fourth embodiment will be described. In the following, identical or equivalent components in each embodiment will be denoted by the same reference numerals, and the descriptions of the components with the same reference numerals will be cited. Furthermore, in this fourth embodiment, the structure of the first embodiment will be used as an example as the basic structure.

[0126] The battery measuring device 50 may be placed on a circuit board and the wiring of the first electrical path 81 and the second electrical path 82 may be fixed. The wiring of the electrical paths 81 and 82 and the connection between the battery cell 42 and the battery measuring device 50 will be described below.

[0127] Figure 10 Schematic diagram showing the connection between the battery unit 42 and the battery measuring device 50 . Figure 10 1 and 2. A plan view of the plurality of battery cells 42 as viewed from the upper surface (the surface on which the power terminals 71 are provided) is shown.

[0128] like Figure 10 As shown, a flat circuit board 72 is disposed between the positive-side power supply terminal 71a and the negative-side power supply terminal 71b. Circuit board 72 is a PCB (printed circuit board) or FPC (flexible printed circuit board). Conductive metal electrical pathways extend around the circuit components arranged on circuit board 72. This secures the positions of the electrical pathways and circuit components. Therefore, in the fourth embodiment, circuit board 72 serves as a fixing member.

[0129] In this case, the signal wiring (electrical path) is basically extended in pairs of two lines. Figure 3The gate terminal of the semiconductor switch element 56a in the circuit sends a signal, and the wiring connected to the gate terminal and the wiring that serves as the so-called return path of the signal are extended in pairs. However, the return lines of two or more signals can also be shared by a single line, a ground plane, a power plane, etc.

[0130] On the circuit board 72, for example, an ASIC unit 50a, a filter unit 55, a current modulation circuit 56, etc. are arranged (fixed) as circuit elements. Figure 10 In FIG. 5 , for convenience of illustration, only the ASIC unit 50 a and the semiconductor switch element 56 a of the current modulation circuit 56 are shown.

[0131] like Figure 10 As shown, the circuit substrate 72 is arranged along the short side direction ( Figure 10 The circuit board 72 is formed so as to extend (in the left-right direction) throughout the stacked battery cells 42. In this case, the circuit board 72 is configured to be disposed between the power terminals 71 of each battery cell 42. Furthermore, it is disposed so as to face the surface where the power terminals 71 are provided.

[0132] The semiconductor switch element 56a is arranged between the power supply terminals 71 of each battery cell 42. On the other hand, the ASIC unit 50a is arranged at one end ( Figure 10 at the right end of the image) and does not overlap with the battery cell 42.

[0133] Moreover, if Figure 10 As shown by the dashed line, a first electrical path 81 is provided to connect the positive-side power supply terminal 71a and the negative-side power supply terminal 71b in a straight line. The semiconductor switching element 56a is disposed on the first electrical path 81. The semiconductor switching element 56a, i.e., the current modulation circuit 56, is configured to output an AC signal from the battery cell 42 via the first electrical path 81.

[0134] In addition, if Figure 10As indicated by the solid line, a second electrical path 82 is provided on the circuit substrate 72, connecting the power terminals 71 of each battery cell 42 to the response signal input terminal 58 of the ASIC unit 50a. Specifically, the second electrical path A 82a, serving as the positive-side detection line connected to the positive-side power terminal 71a, extends linearly from the positive-side power terminal 71a toward the negative-side power terminal 71b and bends at a 90-degree angle midway. The second electrical path A 82a then extends along the longitudinal direction of the circuit substrate 72 toward the ASIC unit 50a and bends toward the ASIC unit 50a at the end of the circuit substrate 72. However, the 90-degree bend in this embodiment is merely an example and does not mean that the wiring does not have a curvature R. The curvature R can be applied as needed. Furthermore, the wiring pattern of the bend does not necessarily need to be 90 degrees; it can also be arcuate or angled as needed.

[0135] Similarly, the second B electrical path 82b, serving as the negative-side detection line connected to the negative-side power supply terminal 71b, within the second electrical path 82 is configured to extend linearly from the negative-side power supply terminal 71b toward the positive-side power supply terminal 71a, bending at a 90-degree angle midway. This bend occurs at a location that does not contact the second A electrical path 82a. The second B electrical path 82b is then formed to extend along the longitudinal direction of the circuit substrate 72 toward the ASIC unit 50a, parallel to the second A electrical path 82a, and bend toward the ASIC unit 50a at the end of the circuit substrate 72. Furthermore, the second electrical path 82 is formed on a different layer, at least at the intersection, so as not to directly intersect with the first electrical path 81.

[0136] Therefore, if Figure 10 As shown, the second A electrical path 82a connected to the ASIC unit 50a is routed along the second B electrical path 82b to a predetermined branch point Br3. That is, the second A electrical path 82a and the second B electrical path 82b are routed in parallel with as little gap as possible.

[0137] The second electrical path A 82a is linearly routed from the branch point Br3 toward the positive power supply terminal 71a, while the second electrical path B 82b is linearly routed from the branch point Br3 toward the negative power supply terminal 71b. The branch point Br3 is located between the positive power supply terminal 71a and the negative power supply terminal 71b in the longitudinal and transverse directions of the battery cell 42.

[0138] Furthermore, if the first electrical path 81 and the second electrical path 82 connected to the same battery cell 42 are arranged on different layers, the parasitic capacitance between the lines may increase due to the dielectric layer such as the intervening layer. Therefore, it is desirable to form them on the same layer whenever possible. Furthermore, if the first electrical path 81 and the second electrical path 82 connected to the same battery cell 42 intersect, it is desirable to route them on different layers only at the intersection. Furthermore, if the second electrical path 82 intersects the first electrical path 81, it is desirable to orthogonally intersect them in such a way as to minimize the intersection area.

[0139] Incidentally, if the second electrical path 82 intersects the first electrical path 81 connected to another battery cell 42 on its way to the ASIC unit 50a, it will pass through another layer and intersect. In this case, the area of ​​the different layers is minimized. In this case, since the electrical path is connected to another battery cell 42, the influence of parasitic capacitance is minimal.

[0140] Furthermore, a first electrical path 81 and a second electrical path 82 are similarly formed in each battery cell 42. However, the second electrical path 82 is arranged so as to minimize overlap with the semiconductor switch element 56a, the first electrical path 81 connected to other battery cells 42, or the second electrical path 82. Specifically, the semiconductor switch element 56a is arranged so as to be staggered in position for each battery cell 42 in the short-side direction of the circuit substrate 72 (the long-side direction of the battery cell 42). Furthermore, the second electrical path 82 is arranged parallel to the other second electrical paths 82 so as not to overlap with other second electrical paths 82 connected to other battery cells 42 when extending in the long-side direction of the circuit substrate 72 (the short-side direction of the battery cell 42). In this case, the second electrical paths 82 are arranged so as to be staggered in position relative to each other in the short-side direction of the circuit substrate 72.

[0141] Moreover, if Figure 11 As shown, the circuit substrate 72 is positioned closer to the housing 42a than the front end of the power terminal 71 in the protruding direction of the power terminal 71. Consequently, the branch point Br3 is positioned between the front ends of the positive and negative power terminals 71a, 71b and the housing 42a in the protruding direction of the positive and negative power terminals 71a, 71b. More specifically, the branch point Br3 is positioned at a position where it abuts the housing 42a across the circuit substrate 72. Furthermore, the second electrical path A 82a is routed linearly along the outer circumference of the housing 42a from this branch point Br3 toward the positive power terminal 71a. On the other hand, the second electrical path B 82b is routed linearly along the outer circumference of the housing 42a from this branch point Br3 toward the negative power terminal 71b.

[0142] In addition, if Figure 11 As shown, each electrical path 81, 82 is connected to the tip of the power terminal 71 via the L-shaped welding plate 74. The AC signal I may reciprocate up and down via the welding plate 74, but the reciprocating magnetic flux from this portion is canceled.

[0143] By configuring as described above, the third embodiment can suppress the size of the magnetic flux passage area S10, thereby reducing errors in the response signal based on the induced electromotive force. Furthermore, the battery cell 42 can be flattened. Furthermore, the magnetic flux passage area S10 can be positioned away from the busbar 73, thereby suppressing the generation of induced electromotive force in the second electrical path 82 due to noise (external signals) flowing through the busbar 73, and thus reducing errors in the response signal. Noise flowing through the busbar 73 includes, for example, noise caused by the operation of the inverter 30.

[0144] (Fifth embodiment)

[0145] Next, a battery measuring device 50 according to a fifth embodiment will be described. In the following, identical or equivalent components in each embodiment will be denoted by the same reference numerals, and the descriptions of the components with the same reference numerals will be cited. Furthermore, in this fifth embodiment, the structure of the fourth embodiment will be used as an example as the basic structure.

[0146] like Figure 12 As shown, in the fifth embodiment, the second A electrical path 82a is wired so that it intersects with the paired second B electrical path 82b at a predetermined interval as it extends along the longitudinal direction of the circuit board 72 toward the ASIC unit 50a. That is, in the fifth embodiment, since the AC signal I flows along the transverse direction of the circuit board 72, the region formed between the second A electrical path 82a and the second B electrical path 82b extending along the longitudinal direction of the circuit board 72 serves as the magnetic flux passage region S10. Furthermore, noise In, an external signal from the inverter 30, also flows along the longitudinal direction of the bus bar 73 (the longitudinal direction of the circuit board 72), and the magnetic flux resulting from this noise passes through the magnetic flux passage region S10.

[0147] Therefore, similar to the second embodiment, the magnetic flux passage area S10 is divided into a first magnetic flux passage area S21 and a second magnetic flux passage area S22 by intersecting the second A electrical path 82a and the second B electrical path 82b at a predetermined interval. The first magnetic flux passage area S21 is a first area surrounded by the second A electrical path 82a, which is arranged closer to the positive-side power supply terminal 71a than the second B electrical path 82b, and the second B electrical path 82b, which is arranged closer to the negative-side power supply terminal 71b than the second A electrical path 82a. The second magnetic flux passage area S22 is a second area surrounded by the second A electrical path 82a, which is arranged closer to the negative-side power supply terminal 71b than the second B electrical path 82b, and the second B electrical path 82b, which is arranged closer to the positive-side power supply terminal 71a than the second A electrical path 82a.

[0148] Furthermore, for the same reasons as in the second embodiment, the induced electromotive force generated by the magnetic flux passing through the first magnetic flux passing region S21 and the induced electromotive force generated by the magnetic flux passing through the second magnetic flux passing region S22 are out of phase by 180 degrees. In other words, the induced electromotive forces are generated so as to cancel each other out.

[0149] Furthermore, the magnitude of the induced electromotive force depends on the magnitude of the magnetic flux passing through the first magnetic flux passage area S21 and the second magnetic flux passage area S22 (more precisely, the magnitude of the temporal change in the magnetic flux). Therefore, the size of the second magnetic flux passage area S22 is set based on the size of each first magnetic flux passage area S21 so that the difference between the first magnetic flux passing through the first magnetic flux passage area S21 and the second magnetic flux passing through the second magnetic flux passage area S22 is within the permissible magnetic flux value range that includes zero. In other words, the size of the second magnetic flux passage area S22 is set based on the size of the first magnetic flux passage area S21 so that the sum of the induced electromotive force generated by the magnetic flux passing through the first magnetic flux passage area S21 and the induced electromotive force generated by the magnetic flux passing through the second magnetic flux passage area S22 is within the permissible electromotive force value range.

[0150] For example, by setting the number and size of the first magnetic flux passage areas S21 to the same degree as the second magnetic flux passage areas S22 and arranging them at equal intervals, the induced electromotive force is easily within the permissible electromotive force range. In addition, the relative positions of the first electrical path 81 and the first magnetic flux passage areas S21, and the relative positions of the first electrical path 81 and the second magnetic flux passage areas S22 are also set so that the induced electromotive force is easily within the permissible electromotive force range. At this time, it is desirable that the number and size of the first magnetic flux passage areas S21, the number and size of the second magnetic flux passage areas S22, the relative positions of the first electrical path 81 and the first magnetic flux passage areas S21, and the relative positions of the first electrical path 81 and the second magnetic flux passage areas S22 are fixed. This can prevent the induced electromotive force from fluctuating due to changes in the settings.

[0151] Furthermore, similarly to the fourth embodiment, the circuit board 72 is arranged in contact with the installation surface of the power terminal 71, and the magnetic flux passage area S10 is extremely small in the protruding direction of the power terminal 71. Therefore, by adopting the above configurations, the generation of induced electromotive force can be further suppressed.

[0152] (Sixth embodiment)

[0153] Next, the battery measuring device 50 of the fourth or fifth embodiment can be modified as follows. In the following, identical or equivalent components in each embodiment are denoted by the same reference numerals, and the descriptions of the components with the same reference numerals are cited. Furthermore, in this sixth embodiment, the structure of the fourth embodiment will be used as an example as the basic structure.

[0154] like Figure 13 As shown, a thin plate-shaped magnetic shield 201 is positioned between the circuit board 72 and the housing 42a. This magnetic shield 201 has insulating films 202 and 203 on both its front and back surfaces, ensuring insulation between the circuit board 72 and the magnetic shield 201, and between the housing 42a and the magnetic shield 201. The circuit board 72 abuts the magnetic shield 201 via the insulating film 202. Furthermore, the magnetic shield 201 abuts the housing 42a via the insulating film 203. Furthermore, the circuit board 72 is positioned between the front end of the power terminal 71 and the housing 42a, in the direction in which the power terminal 71 protrudes.

[0155] The magnetic shield 201 is a perforated metal plate with multiple through-holes. Alternatively, the magnetic shield 201 may be formed as a mesh or grid of metal wires. Furthermore, through-holes may be provided along the electrical paths 81 and 82. Combinations of these structures are also possible.

[0156] This prevents magnetic flux extending along the longitudinal direction of the circuit board 72 from passing through region S10, suppresses the induced electromotive force, and enables highly accurate detection of the response signal. Furthermore, since the circuit board 72 abuts the magnetic shield 201 via the insulating coating 202, heat can be dissipated through the magnetic shield 201.

[0157] Furthermore, the magnetic shield 201 is a perforated metal plate provided with a plurality of through holes, so that an increase in electrostatic capacitance between the first electrical path 81 and the magnetic shield 201 and between the second electrical path 82 and the magnetic shield 201 can be suppressed.

[0158] (Seventh embodiment)

[0159] Next, the battery measuring device 50 of any of the fourth to sixth embodiments can be modified as follows. In the following, identical or equivalent components are denoted by the same reference numerals in each embodiment, and the descriptions of the components with the same reference numerals are cited. Furthermore, in this seventh embodiment, the structure of the fourth embodiment will be used as an example as the basic structure.

[0160] Typically, battery cells 42 are equipped with explosion-proof valves that open when the internal pressure of the battery cells 42 exceeds a specified value, releasing the internal pressure. Space is required for the explosion-proof valve to open, and covering the explosion-proof valve with the circuit board 72 to prevent it from opening is inappropriate. Therefore, the following configuration is employed.

[0161] like Figure 14 As shown, in each battery cell 42, an explosion-proof valve 301 is provided on the surface where the power terminals 71 are located, between the positive-side power terminal 71a and the negative-side power terminal 71b in the longitudinal direction of the battery cell 42. Furthermore, a through-hole 302 is provided in the circuit board 72 to avoid the explosion-proof valve 301. Specifically, the through-hole 302 is provided in the circuit board 72 to ensure a space for the explosion-proof valve 301 to open.

[0162] Furthermore, components and electrical paths disposed on the circuit board 72 are disposed so as to avoid the through-hole 302. When the magnetic shield 201 is disposed in the sixth embodiment, a through-hole must also be provided in the magnetic shield 201 so as to avoid the explosion-proof valve 301.

[0163] The ASIC unit 50a, which has a larger arrangement space, is arranged at the longitudinal end of the circuit board 72 and is not arranged directly above the battery unit 42. Therefore, the through hole 302 for avoiding the explosion-proof valve 301 can be easily provided.

[0164] (Eighth Embodiment)

[0165] Next, the battery measuring device 50 of any of the fourth to sixth embodiments can be modified as follows. In the following, identical or equivalent components in each embodiment are denoted by the same reference numerals, and the descriptions of the components with the same reference numerals are cited. Furthermore, in this eighth embodiment, the structure of the fourth embodiment will be used as an example as the basic structure.

[0166] Generally, since an explosion-proof valve is provided in the battery cell 42, a space for the explosion-proof valve opening is required.

[0167] like Figure 15As shown, in each battery cell 42, an explosion-proof valve 301 is provided on the surface where the power terminals 71 are located, and between the positive-side power terminal 71a and the negative-side power terminal 71b in the longitudinal direction of the battery cell 42. Furthermore, the circuit board 72 is positioned a predetermined distance away from the surface where the power terminals 71 are located, i.e., the explosion-proof valve 301, within the housing 42a. The predetermined distance is sufficient to ensure space for the explosion-proof valve 301 to open. Furthermore, it is desirable that the predetermined distance be sufficient to ensure minimal space for the explosion-proof valve 301 to open. This allows the explosion-proof valve 301 to open.

[0168] In such a configuration, the distance between the second electric path 82 and the housing case 42a increases in the protruding direction of the power terminal 71, and the magnetic flux passage area S10 increases. As a result, the induced electromotive force may increase.

[0169] Therefore, a shield member 401 is provided between the circuit board 72 and the housing case 42a to cover the magnetic flux passage area S10 from the housing case 42a side. Figure 16 As shown, the shield member 401 is formed in a quadrilateral cage shape in which strip-shaped metal wires are braided.

[0170] The bottom surface of the shield member 401 is formed into a rectangular shape along the longitudinal direction of the circuit board 72. Specifically, the bottom surface of the shield member 401 is formed to extend along the transverse direction of the battery cells 42, covering multiple battery cells 42. Wall portions are formed along the outer edge of the bottom surface of the shield member 401, extending in the direction of the protrusion of the power terminals 71. The shield member 401 is positioned between the power terminals 71, with the opening of the shield member 401 facing the housing 42a. Furthermore, the shield member 401 does not need to be shaped like a cage; it can be formed with multiple through-holes in the bottom and wall portions.

[0171] The shield member 401 is arranged between the power terminals 71 in the longitudinal direction of the battery cell 42. The circuit board 72 is arranged on the bottom surface of the shield member 401 from the outside.

[0172] With the above configuration, the planarly extending magnetic flux passage area S10 of the circuit substrate 72 is covered by the bottom surface of the shield member 401. The planarly extending magnetic flux passage area S10 of the circuit substrate 72 is formed between the paired second A electrical path 82a and second B electrical path 82b extending in the longitudinal direction of the circuit substrate 72.

[0173] Furthermore, the bottom and wall portions of the shielding member 401 prevent magnetic flux from passing through a magnetic flux passage area S10 extending in a direction perpendicular to the circuit board 72. The magnetic flux passage area S10 extending in a direction perpendicular to the circuit board 72 is, for example, an area surrounded by the second electrical path 82 extending in the short side direction of the circuit board 72, the housing 42a, and the power supply terminal 71.

[0174] This can suppress the generation of induced electromotive force in the second electric path 82 and improve the detection accuracy of the response signal.

[0175] Furthermore, since the circuit board 72 abuts the shielding member 401, heat can be dissipated through the shielding member 401. Furthermore, the shielding member 401 is formed in a cage shape, with its opening located on the side of the housing 42a. Therefore, the shielding member 401 does not obstruct the opening of the explosion-proof valve 301. Furthermore, since the walls of the shielding member 401 are provided with multiple through-holes, gas exhausted through the explosion-proof valve 301 can escape through the walls of the shielding member 401.

[0176] Furthermore, since the plurality of through holes are provided in the bottom portion of the shield member 401 , it is possible to suppress an increase in electrostatic capacitance between the first electrical path 81 and the shield member 401 and between the second electrical path 82 and the shield member 401 .

[0177] (Ninth embodiment)

[0178] The battery measuring device 50 of any of the fourth to eighth embodiments can be modified as follows. In the following, identical or equivalent components in each embodiment are denoted by the same reference numerals, and the descriptions of the components with the same reference numerals are cited. Furthermore, in this ninth embodiment, the structure of the fourth embodiment will be used as an example as the basic structure.

[0179] like Figure 17 As shown, the end portion of the circuit substrate 72 in the fourth embodiment in the longitudinal direction (the transverse direction of the battery cell 42) is bent. In the fourth embodiment, the portion of the circuit substrate 72 that faces the upper surface of the battery cell 42 and is positioned between the power terminals 71 of the battery cell 42 is the first substrate 72a, and the bent end portion is the second substrate 72b. However, the 90-degree bend in this embodiment is merely an example, and any angle is acceptable.

[0180] In this embodiment, the circuit substrate 72 may be formed by bending an FPC, or a first substrate 72a and a second substrate 72b may be provided separately and connected to each other through a connector or FPC. When the FPC is bent, the first substrate 72a and the second substrate 72b are not physically separate but are the same substrate. However, for ease of explanation, they are referred to as the first substrate 72a and the second substrate 72b.

[0181] The bent second substrate 72b is positioned perpendicular to the plane of the first substrate 72a and opposite the side surfaces of the battery cell 42. Therefore, the second electrical path 82 or the ASIC unit 50a, located at the end of the circuit substrate 72, is not flush with the first electrical path 81, the current modulation circuit 56, and the like. Furthermore, when the ASIC unit 50a and the first electrical path 81 and the like are not flush with each other, the electrical path on the second substrate 72b or the ASIC unit 50a is affected by the magnetic flux density vector of the AC signal in a different manner than when the first and second electrical paths 81, 82 are flush with each other.

[0182] Therefore, a cylindrical portion 501 is provided as a shielding member to surround the perimeter of the second substrate 72b. Specifically, the cylindrical portion 501 is formed into a square cylindrical shape using a conductor such as metal, resin, or carbon, and the second substrate 72b is housed within the cylindrical portion 501. This suppresses the influence of the magnetic flux density vector caused by the AC signal, reduces the effects of external magnetic fields, and improves the accuracy of complex impedance calculation.

[0183] Furthermore, by bending the second substrate 72b perpendicular to the plane of the first substrate 72a, the longitudinal distance can be shortened compared to when the substrate 72b is arranged on the same plane. Furthermore, by arranging the second substrate 72b opposite the side surface of the battery cell 42, miniaturization can be achieved.

[0184] In addition, if Figure 17 As shown in (b), the upper portion of the cylindrical portion 501 (on the side facing the power terminal 71) is open, while a bottom portion 502 is formed on the lower portion (on the side facing the bottom surface of the battery cell 42). This bottom portion 502 is provided with a through-hole 502a extending vertically therethrough, allowing air to flow vertically. This allows for optimal heat dissipation from the second substrate 72b.

[0185] In addition, in this embodiment, the cylindrical portion 501 and the housing 42a of the battery cell 42 are constructed separately, but they can also be partially shared. For example, the side surface of the housing 42a of the cylindrical portion 501 can be shared with the side surface of the cylindrical portion 501 of the housing 42a. Furthermore, not limited to the housing 42a of the battery cell 42, a portion of the housing (power supply housing) of the battery pack 40 can also be shared with a portion of the cylindrical portion 501. This can achieve miniaturization.

[0186] (Tenth embodiment)

[0187] Next, the battery measuring device 50 of any of the first to ninth embodiments can be modified as described below. In the following, identical or equivalent components in each embodiment are denoted by the same reference numerals, and the descriptions of the components with the same reference numerals are cited. Furthermore, in this tenth embodiment, the structure of the first embodiment is used as an example as the basic structure. The battery measuring device 50 of the tenth embodiment implements so-called two-phase lock detection.

[0188] like Figure 18 As shown, the ASIC unit 50a of the battery measuring device 50 is provided with a differential amplifier 151 for measuring the DC voltage between the terminals of the battery cell 42. The differential amplifier 151 is connected to the positive terminal 57a and the negative terminal 57b of the DC voltage input terminal 57, and is configured to measure and output the DC voltage.

[0189] Furthermore, the ASIC unit 50a of the battery measuring device 50 includes a preamplifier 152, which serves as an amplifier that receives voltage fluctuations of the battery cell 42 when a sinusoidal wave signal is output via the response signal input terminal 58. The preamplifier 152 amplifies the voltage fluctuations input via the response signal input terminal 58 and outputs it as a response signal. Specifically, the amplitude of the response signal is weak compared to the voltage of the battery cell 42. Therefore, the preamplifier 152 is provided to improve the detection accuracy of the response signal. While the preamplifier 152 is a single-stage amplifier in the tenth embodiment, it may also be a multi-stage amplifier.

[0190] In addition, if Figure 18 As shown, a capacitor C1 for removing DC components is provided between the positive-side power supply terminal 71a of the battery cell 42 and the positive-side response signal input terminal 58 (the positive-side terminal of the preamplifier 152). This removes the DC component (the portion unrelated to the internal complex impedance information) in the voltage fluctuation of the battery cell 42, thereby improving the detection accuracy of the response signal. Similarly, a capacitor C2 is provided at the negative-side power supply terminal 71b of the battery cell 42.

[0191] Furthermore, the ASIC unit 50a is provided with a signal switching unit 153 that switches between the DC voltage output from the differential amplifier 151 and the response signal output from the preamplifier 152. The signal switching unit 153 is connected to an AD converter 154 and is configured to convert the switched signal (analog signal) into a digital signal and output the digital signal.

[0192] The AD converter 154 is connected to the signal processing unit 155 as the calculation unit in the tenth embodiment and receives a DC voltage as input. The AD converter 154 is also connected to the first multiplier 156 and the second multiplier 157 and receives a response signal as input.

[0193] The first multiplier 156 is connected to the oscillation circuit 158 ​​described later and receives the first reference signal as input. The first multiplier 156 multiplies the first reference signal by the response signal to calculate a value proportional to the real part of the response signal, and outputs the value proportional to the real part of the response signal to the signal processing unit 155 via the low-pass filter 159. Figure 18 In , the real part of the response signal is represented as Re|Vr|.

[0194] Second multiplier 157 is connected to oscillator circuit 158 ​​via phase shift circuit 160 and receives a second reference signal as input. The second reference signal is a signal obtained by shifting the phase of the first reference signal by 90 degrees (π / 2). Phase shift circuit 160 shifts the phase of the sinusoidal wave signal (first reference signal) input from oscillator circuit 158 ​​and outputs it as the second reference signal.

[0195] The second multiplier 157 multiplies the second reference signal by the response signal to calculate a value proportional to the imaginary part of the response signal, and outputs the value proportional to the imaginary part of the response signal to the signal processing unit 155 via the low-pass filter 161. Figure 18 In , the imaginary part of the response signal is represented as Im|Vr|.

[0196] Oscillator circuit 158 ​​is a circuit that outputs a set sinusoidal wave signal and functions as a waveform indicator. As described above, oscillator circuit 158 ​​outputs the sinusoidal wave signal as a first reference signal to first multiplier 156 and phase shift circuit 160. Oscillator circuit 158 ​​is also connected to instruction signal output terminal 59a via D / A converter 162 and outputs the sinusoidal wave signal as an instruction signal.

[0197] The feedback signal input terminal 59b is connected to the AD converter 163. The feedback signal input terminal 59b is connected to the signal processing unit 155 via the AD converter 163. The signal processing unit 155 receives a feedback signal (detection signal) from the feedback signal input terminal 59b via the AD converter 163.

[0198] Further, the AD converter 163 is configured to be connected to the third multiplier 164 and the fourth multiplier 165, and input the feedback signal (detection signal) respectively. The oscillation circuit 158 is connected to the third multiplier 164, and the third multiplier 164 inputs the first reference signal. The third multiplier 164 multiplies the first reference signal and the feedback signal to calculate a value proportional to the real part of the feedback signal, and outputs the value proportional to the real part of the feedback signal to the signal processing section 155 via the low pass filter 166. In addition, in the present embodiment, the real part of the feedback signal is expressed as Re|Vf|. Figure 18

[0199] The fourth multiplier 165 is connected to the oscillation circuit 158 via the phase shift circuit 160, and inputs the second reference signal. The fourth multiplier 165 multiplies the second reference signal and the feedback signal to calculate a value proportional to the imaginary part of the feedback signal, and outputs the value proportional to the imaginary part of the feedback signal to the signal processing section 155 via the low pass filter 167. In addition, in the present embodiment, the imaginary part of the feedback signal is expressed as Im|Vf|. That is, the lock detection of the feedback signal is performed. Figure 18

[0200] The signal processing section 155 inputs the value proportional to the real part of the response signal and the value proportional to the imaginary part of the response signal, and calculates the real part and the imaginary part of the complex impedance based on the above values. At this time, the signal processing section 155 calculates (corrects) the real part and the imaginary part of the complex impedance using the input real part and the imaginary part of the feedback signal, and considering the amplitude of the actually flowing signal and the phase deviation of the reference signal.

[0201] Further, the signal processing section 155 calculates the absolute value and the phase of the complex impedance. In detail, since the real part and the imaginary part of the response signal can be known by the two-phase lock detection, if the phase of the response signal is set to θv, it can be expressed as |Vr|e jθv in the polar coordinate expression in the complex plane. Similarly, the current can be expressed as |I|e jθi . Thus, if the polar coordinate expression of the complex impedance is set to |Z|e jθz , it can be expressed as mathematical expression (2) according to V=ZI. That is, "j" is a complex number satisfying j 2 =-1.

[0202] [mathematical expression 2]

[0203]

[0204] ​​Accordingly, the absolute value of the complex impedance can be found from |Z| = |Vr| / |I|, and the phase can be found from θv- θi. Then, the signal processing portion 155 outputs the calculation results to the ECU 60 via the communication portion 54. Also, in the tenth embodiment, the absolute value of the complex impedance is denoted as |Z|, and the phase thereof is denoted as arg(Z). Figure 18

[0205] Next, based on Figure 19 The complex impedance calculation processing in the tenth embodiment will be described. The complex impedance calculation processing is executed by the battery measuring device 50 at a prescribed period.

[0206] In the complex impedance calculation processing, the oscillation circuit 158 first sets the measurement frequency of the complex impedance (step S201). The measurement frequency is set from among the frequencies in the measurement range determined in advance. In the tenth embodiment, the measurement frequency is determined by the signal processing portion 155, for example.

[0207] Next, the signal switching portion 153 performs switching to output the response signal from the preamplifier 152 (step S202). The instruction of the switching is performed by the signal processing portion 155, for example.

[0208] Next, the oscillation circuit 158 determines the frequency of the sinusoidal wave signal (prescribed alternating current signal) based on the measurement frequency, and outputs an instruction signal that instructs the output of the sinusoidal wave signal from the instruction signal output terminal 59a to the current modulation circuit 56 via the DA converter 162 (step S203). Also, the output instruction of the instruction signal is performed by the signal processing portion 155, for example. When converted to an analog signal by the DA converter 162, an appropriate offset value (direct current bias) is set in consideration of the voltage of the battery cell 42 and converted. The setting of the offset value (direct current bias) is performed by the signal processing portion 155, for example. The setting of the desired offset value (direct current bias) is performed based on the direct current voltage of the battery cell 42. Also, it is sufficient that the direct current voltage of the battery cell 42 is measured by the differential amplifier 151.

[0209] The current modulation circuit 56 causes the sinusoidal wave signal (alternating current signal I) to be output using the battery cell 42 as a power source based on the instruction signal (step S204). Thereby, the sinusoidal wave signal (alternating current signal I) is output from the battery cell 42.

[0210] When the sinusoidal wave signal is output from the battery cell 42, a voltage variation that reflects the internal complex impedance information of the battery cell 42 is generated between the terminals of the battery cell 42. The preamplifier 152 inputs this voltage variation via the response signal input terminal 58 and outputs as a response signal (step S205).

[0211] ​In addition, when input to the response signal input terminal 58, the direct current component of the voltage variation is removed by the capacitors C1, C2, and only the characteristic portion of the voltage variation is extracted. Furthermore, the preamplifier 152 amplifies the weak voltage variation from which the direct current component has been removed, and outputs this as a response signal. At this time, the AD converter 154 converts the response signal input via the signal switching section 153 to a digital signal and outputs this. It is desirable to adjust the magnitude of the direct current component removed by the capacitors C1, C2 based on the direct current voltage of the battery cell 42. Likewise, it is desirable to adjust the degree to which the voltage variation is amplified based on the direct current voltage of the battery cell 42.

[0212] The first multiplier 156 sets the sine wave signal input from the oscillation circuit 158 as a first reference signal, and multiplies this by the response signal input from the AD converter 154 to calculate a value proportional to the real part of the response signal (step S206). Likewise, the second multiplier 157 multiplies the second reference signal input from the phase shift circuit 160 by the response signal to calculate a value proportional to the imaginary part of the response signal.

[0213] The above values are input to the signal processing section 155 via the low pass filter 159 and the low pass filter 161. In addition, when passing through the low pass filter 159 and the low pass filter 161, signals other than the direct current component (DC component) are attenuated and removed.

[0214] The signal processing section 155 inputs a feedback signal (detection signal) from the feedback signal input terminal 59b (step S207). In detail, the real part and the imaginary part of the feedback signal detected by the lock are input.

[0215] The signal processing section 155 calculates all or any one of the real part, the imaginary part, the absolute value, and the phase of the complex impedance based on the feedback signal and the signals (proportional values of the real part and the imaginary part) input from the low pass filter 159, 161 (step S208). The feedback signal is used to correct the deviation in amplitude or phase between the current actually flowing from the battery cell 42 (i.e., the feedback signal) and the value proportional to the reference signal.

[0216] After this, the signal processing section 155 outputs the calculation result to the ECU 60 via the communication section 54 (step S209). Then, the calculation processing ends.

[0217] This calculation processing is repeatedly executed until the complex impedance for a plurality of frequencies within the measurement range is calculated. The ECU 60 creates a complex impedance plane graph (Cole-Cole plot) based on the calculation result, and thereby grasps the characteristics of the electrode and the electrolyte, etc. For example, the state of charge (SOC), the state of health (SOH) are grasped.

[0218] Furthermore, it is not necessary to create the entire Cole-Cole plot; a portion of the plot may be considered. For example, complex impedance at a specific frequency may be measured at regular intervals during driving, and changes in SOC, SOH, battery temperature, and the like during driving may be understood based on the temporal changes in the complex impedance at this specific frequency. Alternatively, complex impedance at a specific frequency may be measured at daily, weekly, or yearly intervals, and changes in SOH and the like may be understood based on the temporal changes in the complex impedance at this specific frequency.

[0219] The battery measuring device 50 of the tenth embodiment has the following effects.

[0220] The signal processing unit 155 calculates a value proportional to the real part of the response signal based on the value obtained by multiplying the response signal input from the response signal input terminal 58 by the first reference signal. Furthermore, the signal processing unit 155 uses a phase-shifted sine wave signal as the second reference signal and calculates a value proportional to the imaginary part of the response signal based on the value obtained by multiplying the response signal by the second reference signal. Complex impedance is then calculated based on these values. By performing so-called lock detection in this way, only the frequency component corresponding to the frequency of the sine wave signal indicated by the oscillation circuit 158 ​​can be extracted from the response signal. This improves immunity to white and pink noise, enabling highly accurate calculation of complex impedance. This makes complex impedance calculation particularly ideal for use in vehicles, where noise levels are high. Furthermore, due to this enhanced noise immunity, the current (sine wave signal) output from the battery cell 42 can be reduced. Consequently, power consumption and temperature increases in the battery cell 42 and semiconductor switching element 56a can be suppressed.

[0221] Furthermore, the signal processing unit 155 receives a feedback signal (detection signal) from the current modulation circuit 56 that detects the current actually flowing out of the battery cell 42 and corrects any deviations in amplitude and phase from a value proportional to the reference signal. This improves the accuracy of complex impedance calculation.

[0222] Furthermore, since amplitude and phase deviations are corrected, even if errors occur when converting the command signal to an analog signal, these errors can be suppressed by corrections implemented using the feedback signal. Consequently, there is no need for a filter circuit or the like between the current modulation circuit 56 and the DA converter 162, enabling miniaturization.

[0223] (Other embodiments)

[0224] In the above embodiment, the battery measuring device 50 is provided for each battery module 41. However, for example, a battery measuring device 50 may be provided for each battery cell 42 or each battery pack 40. Furthermore, when a battery measuring device 50 is provided for each of the plurality of battery cells 42, some of the functions of the battery measuring device 50 may be shared.

[0225] For example, Figure 20 As shown, the stabilized power supply unit 601, the communication unit 54, the differential amplifier 151, the preamplifier 152, the signal switching unit 153, the AD converters 154 and 163, the signal processing unit 155, the multipliers 156, 157, 164 and 165, the low-pass filters 159, 161, 166 and 167, the oscillation circuit 158, the phase shift circuit 160, the DA converter 162, the feedback circuit 56d, the current detection amplifier 56c and the like can also be shared.

[0226] In this case, it is sufficient to configure the system so that various signals, such as DC voltage, response signal, and instruction signal, can be switched using a multiplexing device such as multiplexers 602-604. Furthermore, in this case, the potential of the negative electrode may differ for each battery cell 42. Therefore, the reference potential of each electrical signal used to transmit information from each battery cell 42 may differ. Therefore, a function is required to input each electrical signal to the signal processing unit 155 for calculation, taking into account the difference in reference potential. Signal transmission methods between different reference potentials include capacitors, transformers, radio waves, and light.

[0227] In the above embodiment, the filter unit 55 does not need to be composed only of components. For example, it may be composed of wiring, connector contacts, pattern wiring on a printed circuit board, solid patterns, or a mixture of the above structures and components.

[0228] In the above embodiment, a filter circuit may be provided between the current modulation circuit 56 and the input / output unit 52 (or the DA converter 162). This can suppress errors in converting the instruction signal into an analog signal.

[0229] In the above embodiment, the feedback circuit 56d may not be provided. Furthermore, the current detection amplifier 56c may not be used to detect the current flowing through the resistor 56b. Furthermore, the microcomputer unit 53 and the signal processing unit 155 may not input a feedback signal.

[0230] In the above embodiment, the DC voltage is detected, but this does not have to be the case. Furthermore, in the above embodiment, the signal switching unit 153 does not have to be provided. Furthermore, in the above embodiment, the feedback signal can be switched by the signal switching unit 153. This allows the AD converters 154 and 163 to be shared.

[0231] The battery measuring device 50 of the above embodiment can also be used for HEV, EV, PHV, auxiliary equipment batteries, electric aircraft, electric motorcycles, and electric ships. In the above embodiment, the battery cells 42 can also be connected in parallel.

[0232] In the tenth embodiment described above, in order to prevent aliasing during AD conversion, a filter circuit may be provided before or after the preamplifier 152 or immediately before the AD converter 154 .

[0233] In the above embodiment, the status can also be measured for each battery module 41. In this case, if a communication unit 54 is provided for each battery module 41, communication from each communication unit 54 to the ECU 60 may be isolated communication with different potential references. For example, an isolation transformer or capacitor may be used for isolated communication. Alternatively, the status can be measured for each battery pack 40.

[0234] In the above embodiment, the current signal (AC signal I) output from the battery cell 42 is not limited to a sine wave signal. For example, any AC signal may be a rectangular wave, a triangular wave, or the like.

[0235] In the above embodiment, the ECU 60 may be composed of multiple ECUs. For example, multiple ECUs may be provided for each function, or multiple ECUs may be provided for each control target. For example, the ECU may be divided into a battery ECU and an inverter control ECU.

[0236] In the above embodiment, when performing lock detection, the sinusoidal wave signal indicated by the oscillation circuit 158 ​​is used as the reference signal (first reference signal). However, the detection signal (feedback signal) may also be used as the reference signal. Furthermore, when performing two-phase lock detection, the detection signal (feedback signal) may be phase-shifted to serve as the second reference signal.

[0237] In the above embodiment, the battery unit 42 (battery module 41, battery pack 40) can be used as a power source for the peripheral circuits when outputting a sine wave signal in response to an instruction (when outputting a response signal). Conversely, the battery unit 42 (battery module 41, battery pack 40) can be configured not to be used as a power source for the peripheral circuits when outputting a sine wave signal in response to an instruction (when outputting a response signal).

[0238] In the above embodiment, when wiring the electric paths on different layers of the circuit board 72, it is desirable to wire them in a staggered manner. This can reduce parasitic capacitance.

[0239] In the above embodiment, an AC signal is output from the battery cell 42. However, an external power source may be used to input an AC signal to the battery cell 42, thereby applying external interference. In this case, to prevent the state of charge (SOC, etc.) of the battery cell 42 from changing due to the input of the AC signal, an AC signal may be input that equalizes the charge and discharge amounts. Alternatively, the charge and discharge amounts may be adjusted to a desired value by creating a difference between the charge and discharge amounts. In the case of a vehicle-based battery measuring device 50, the external power source may be either onboard or external to the vehicle.

[0240] For example, Figure 21 As shown in (a), the battery measuring device 50 may include an AC constant current source 701 to input an AC constant current as an AC signal to the battery cell 42. The computing unit 702 of the battery measuring device 50 then inputs a response signal via a voltmeter 703 and calculates the impedance based on the AC signal and the response signal.

[0241] In this case, if Figure 21 As shown in (b), the electrical path connecting the battery cell 42 and the AC constant current source 701 corresponds to the first electrical path 81, and the electrical path connecting the battery cell 42 and the voltmeter 703 corresponds to the second electrical path 82. Figure 21 As shown in (b), the wiring of the second electric path 82 may be performed in the same manner as in the above embodiment.

[0242] In addition, for example, Figure 22 As shown in (a), the battery measuring device 50 may include an AC constant voltage source 711 to input an AC constant voltage as an AC signal to the battery cell 42. The computing unit 712 of the battery measuring device 50 then inputs a response signal (current fluctuation) via an ammeter 713a and a current sensor 713b and calculates the impedance based on the AC signal and the response signal.

[0243] In this case, if Figure 22 As shown in (b), the voltage applying line 791 provided with the current sensor 713b corresponds to the first electrical path 81, and the voltage sensing line 792 connecting the battery cell 42 and the AC constant voltage source 711 corresponds to the second electrical path 82. Figure 22As shown in (b), the wiring of the voltage sensing line 792 (second electrical path 82) can be performed in the same manner as in the above embodiment. Alternatively, the voltage applying line 791 and the voltage sensing line 792 may all or partly be covered with the same magnetic shield.

[0244] In the above embodiment, the shape of the battery cell 42 can also be changed arbitrarily. Figure 23 As shown in FIG. 1 , it can also be adopted in a battery 720 having a cylindrical shape and power supply terminals 721 and 722 provided on the upper and lower surfaces. Figure 23 As shown, the branch point Br21 of the second electrical path 82 is set on the outer peripheral surface of the battery 720 and the wiring is arranged along the battery 720 from the branch point Br21. Figure 24 As shown, the same can also be adopted in the battery cell 42 on the laminate side.

[0245] In the above embodiment, a magnetic shield surrounding the power terminal 71 may be provided on the surface where the power terminal 71 is provided in each battery cell 42. The magnetic shield provided on the surface where the power terminal 71 of the battery cell 42 is provided may be provided in a wall-like manner so as to surround the power terminal 71 in a portion other than the inner side in the longitudinal direction of the battery cell 42 (i.e., the side where the circuit substrate 72 is arranged). In addition, in order to avoid interference with the busbar 73, the height of the magnetic shield is preferably less than the height of the power terminal 71. Alternatively, a magnetic shield surrounding the power terminal 71 may be provided on the circuit substrate 72. The magnetic shield provided on the circuit substrate 72 may be provided so as to surround the power terminal 71 from the inner side in the longitudinal direction of the battery cell 42.

[0246] In the above embodiment, the electrical paths 81 and 82 may be fixed using a fixing member such as a resin mold. This fixing can suppress changes in the size of the magnetic flux passage area S10. Furthermore, changes in the relative positions of the electrical paths 81 and 82 can be suppressed. Consequently, changes in the induced electromotive force can be suppressed.

[0247] In the second embodiment described above, when the area is divided into the first magnetic flux passing area S11 and the second magnetic flux passing area S12, a member having a magnetic permeability different from that of air may be arranged in either the first magnetic flux passing area S11 or the second magnetic flux passing area S12, thereby adjusting the area so as to reduce the difference in the passing magnetic flux.

[0248] In the second embodiment described above, the magnetic flux passage area S10 may be divided into three or more areas. In this case, the second electric paths 82 are made to intersect with each other multiple times.

[0249] In the above embodiment, when the first electric path 81 is freely configurable, the relative positions of the first electric path 81 and the magnetic flux passage area S10 are preferably set so that the induced electromotive force falls within the permissible electromotive force value range.

[0250] In the first to third embodiments, the second A electrical path 82a and the second B electrical path 82b may be twisted until they branch off. This allows the induced electromotive forces to cancel each other out, thus suppressing the induced electromotive forces.

[0251] In the sixth embodiment, if Figure 25 As shown, a magnetic shield 750 may be provided to cover the upper surface of the circuit board 72 (the surface opposite to the lower surface facing the housing case 42 a ).

[0252] In the ninth embodiment, a battery case may be provided to house a plurality of battery cells 42. Furthermore, the cylindrical portion 501 may be integrated with the end of the battery case. Furthermore, if the number of battery cells 42 is large, the cylindrical portion 501 may be disposed between the stacked battery cells 42.

[0253] In the above embodiment, the battery measuring device 50 may also measure the state of a battery other than the vehicle-mounted battery pack 40 .

[0254] In the fourth embodiment described above, the circuit board 72 may also be bent arbitrarily.

[0255] In the ninth embodiment, a through hole may be formed in any location other than the bottom 502 of the cylindrical portion 501. For example, the through hole may be formed on the side of the cylindrical portion 501. Furthermore, a gap may be provided between the cylindrical portion 501 and the housing 42a. This can improve cooling performance. Furthermore, a magnetic shield having a through hole may be used to cover the opening of the cylindrical portion 501. This can suppress the effects of noise.

[0256] In the above embodiment, the method of measuring and calculating the amplitude and phase of the complex impedance at a specific frequency is not limited to lock detection, and heterodyne detection, Fourier transform, etc. may be used.

[0257] In the above-described embodiment, a computing unit such as the microcomputer unit 53 does not need to calculate the absolute value and phase difference of the complex impedance. Instead, information related to the complex impedance can be calculated based on the response signal and the current signal, and output to an external device such as the ECU 60. Furthermore, the information related to the complex impedance can be, for example, intermediate information (e.g., only the real and imaginary parts of the current and voltage) required to calculate the absolute value and phase difference of the complex impedance. Furthermore, the final result, i.e., the absolute value and phase difference of the complex impedance, can be calculated by an external device.

[0258] In the second embodiment, the branch point Br2 may be positioned between the power terminals 71 in the longitudinal and transverse directions of the battery cell 42 and between the distal end of the power terminal 71 and the housing case 42 a in the protruding direction.

[0259] In the eighth embodiment described above, if Figure 26 As shown, a protective plate 410 covering the top of the explosion-proof valve 301 can also be provided at the bottom of the shielding member 401 (the portion where the circuit substrate 72 is provided). Thus, even if the explosion-proof valve 301 is opened and gas is ejected, the protective plate 410 can reliably prevent the circuit substrate 72 from being damaged. The side of the shielding member 401 can also be composed of a side wall 411 that has no holes except for the portion where the gas pipe is connected. Moreover, a through hole 412 can be provided in the side wall 411 at a position corresponding to the gas pipe (not shown). Thus, the gas ejected from the explosion-proof valve 301 can be guided to the gas pipe via the through hole 412.

[0260] In the above embodiment, the housing 42a may be connected to the negative power supply terminal 71b. In this case, the negative power supply terminal 71b may not be formed to protrude. Furthermore, the second B electrical path 82b as the negative detection line may be wired from the branch points Br1, Br2, Br3, and Br21 toward the housing 42a and connected to the housing 42a. Specifically, Figure 37 As shown, the wiring may be linearly routed from the branch points Br1, Br2, Br3, and Br21 toward the housing case 42a. In this case, the positive-side power supply terminal 71a is insulated from the housing case 42a.

[0261] It goes without saying that the magnetic flux passage region S10 is set so that the induced electromotive force generated in the second electrical path 82 by the AC signal flowing through the first electrical path 81 is within the permissible electromotive force value range including zero. Furthermore, as long as this condition is met, the branch points Br1, Br2, Br3, and Br21 can be set at any location.

[0262] • In the above-described embodiment, the size and shape of the magnetic flux passing region S10 can be arbitrarily changed with respect to the branch point Br1 of the second electric path 82, as long as the magnetic flux passing region S10 is set such that the induced electromotive force generated in the second electric path 82 based on the alternating current signal flowing through the first electric path 81 is within the electromotive force allowable value range including zero.

[0263] For example, in the first embodiment, the branch point Br1 of the second electric path 82 can also be disposed at a position further from the opposite side of the housing case 42a than the front end positions of the positive side power terminal 71a and the negative side power terminal 71b in the protruding direction of the power terminal 71. That is, the branch point Br1 can also be disposed further from the housing case 42a than the front end positions of the positive side power terminal 71a and the negative side power terminal 71b.

[0264] In addition, the branch point Br1 of the second electric path 82 can also be disposed between the positive side power terminal 71a and the negative side power terminal 71b in the opposite direction (left-right direction) of the positive side power terminal 71a and the negative side power terminal 71b. That is, it can also be disposed outside of the battery cell 42 (housing case 42a) in the left-right direction. Similarly, the branch point Br1 of the second electric path 82 can also be disposed outside of the battery cell 42 (housing case 42a) in the thickness direction (short side direction) of the housing case 42a. Figure 5

[0265] • In the above-described embodiment, the magnetic flux passing region S10 is a region surrounded by the second electric path 82, the power terminal 71, and the housing case 42a, but corresponds to a region surrounded by the second electric path 82 and the battery cell 42. The magnetic flux passing region S10 can also be a region surrounded by the positive electrode, the negative electrode, the electrode group housed in the housing case 42a, and the second electric path 82 of the battery cell 42.

[0266] • In the above-described embodiment, the size and shape of the magnetic flux passing region S10 can be arbitrarily changed as long as the error between the actual complex impedance of the battery cell 42 and the complex impedance calculated by the microcomputer section 53 is set to be within the ±1 mΩ range.

[0267] Here, a more desirable range is described. Figure 27 The relationship between the battery capacity (Ah) of the battery cell 42 and the required impedance value measurement accuracy is shown. The required impedance value measurement accuracy refers to the accuracy required to find the zero-crossing point. In addition, as shown in (a) to (d) of FIG. 10, it is known that the required impedance value measurement accuracy varies depending on the battery temperature (°C) of the battery cell 42. Therefore, depending on the battery temperature (°C) of the battery cell 42, the size and shape of the magnetic flux passing region S10 can be arbitrarily changed. Figure 27 Figure 27 Figure 27 ​​​When the battery capacity is 25Ah to 800Ah and the battery temperature is -10°C to 65°C, as long as the error between the actual complex impedance of the battery cell 42 and the complex impedance calculated by the microcomputer unit 53 is set to be within the range of ±170μΩ, the size of the magnetic flux passing area S10 can be arbitrarily changed.

[0268] The actual complex impedance of the battery cell 42 refers to the value calculated when the magnetic flux passage area S10 is zero or as close to zero as possible, or the value obtained by quantifying and correcting the error (the influence of the induced electromotive force due to the wiring shape) caused by the magnetic flux passage area S10 using a predetermined mathematical formula. Alternatively, the four-terminal method or the four-terminal pair method may be used. The error in the complex impedance refers to any error in the absolute value, real part, or imaginary part of the complex impedance.

[0269] (Variation 1)

[0270] Next, a modification example 1 is described, in which a portion of the structure of the above-described embodiment is modified. In the following, identical or equivalent parts in each embodiment and modification example are denoted by the same reference numerals, and the descriptions of the parts with the same reference numerals are cited. In this modification example, the structure of the first embodiment is used as an example as the basic structure.

[0271] In the power supply system of variant example 1, as in the first embodiment, it includes: an electric motor 20 as a rotating electrical machine; an inverter 30 as a power converter for passing a three-phase current through the electric motor 20; a battery pack 140 that can be charged and discharged; a battery measuring device 50 for measuring the state of the battery pack 140; and an ECU 60 for controlling the electric motor 20, etc.

[0272] like Figure 28 As shown, the battery pack 140 in the first modification is composed of a plurality of battery cells 142 connected in series. Figure 28 As shown in (a), the battery cell 142, and more specifically, its housing 142a, is formed into an elongated cylindrical shape. The battery cell 142 has one end ( Figure 28 The positive side power supply terminal 171a is provided on the upper surface of the Figure 28 A negative-side power terminal 171b is provided on the lower surface of the battery cell 142. Specifically, the battery cell 142 of this embodiment is constructed by housing a cylindrical wound body, such as a nickel-metal hydride battery or a nickel-cadmium battery, formed by rolling up an electrode assembly 142b. The positive-side power terminal 171a protrudes axially from the housing case 142a.

[0273] Moreover, if Figure 28As shown in (b), each battery cell 142 is arranged in one or more rows. In this modification 1, it is arranged in two rows. At this time, in the adjacent front and back rows, the positive side power supply terminal 171a and the negative side power supply terminal 171b are arranged in a manner different from each other. In addition, Figure 28 In (b), the positive side power terminal 171a of the first column (the battery cells 142 on the inner side have four columns) is arranged at the top in the figure, and the positive side power terminal 171a of the second column (the battery cells 142 on the near side have three columns) is arranged at the bottom in the figure.

[0274] In addition, Figure 28 In (b), the device is placed vertically with the longitudinal direction (axial direction) becoming the vertical direction, but the arrangement method is arbitrary, and the device may be placed horizontally with the horizontal plane being parallel to the longitudinal direction.

[0275] Moreover, if Figure 28 As shown in (b), the positive power terminal 171a of the battery cell 142 is connected to the negative power terminal 171b of the battery cell 142 in the adjacent row via a bus bar 173, thereby connecting the battery cells 142 in series. Furthermore, the negative power terminal 171b of the battery cell 142 is connected to the positive power terminal 171a of the battery cell 142 in the adjacent row via a bus bar 173. The bus bar 173 is made of a conductive material and is formed into a thin plate having a length sufficient to allow the adjacent power terminals 171 to reach.

[0276] As in the above-described embodiment, each battery cell 142 serves as a measurement target for the battery measuring device 50. Specifically, the positive power supply terminal 171a of each battery cell 142 is connected to the second A electrical path 82a, which serves as the positive detection line of the ASIC unit 50a, and the negative power supply terminal 171b is connected to the second B electrical path 82b, which serves as the negative detection line of the ASIC unit 50a. Furthermore, the positive power supply terminal 171a and the negative power supply terminal 171b of each battery cell 142 are each connected to the first electrical path 81. More specifically, the positive power supply terminal 171a of each battery cell 142 is connected to the first A electrical path 81a, which serves as the positive modulation line of the first electrical path 81, and the negative power supply terminal 171b is connected to the first B electrical path 81b, which serves as the negative modulation line of the first electrical path 81. Furthermore, the first electrical path 81 is connected to the current modulation circuit 56.

[0277] In addition, if Figure 28As shown, the battery cell 142 needs to be structurally provided with a positive pole and a negative pole (i.e., a positive-side power terminal 171a and a negative-side power terminal 171b). Therefore, as in the first embodiment, it is necessary to branch the second A electrical path 82a and the second B electrical path 82b midway. Therefore, in this modification 1, a magnetic flux passage area S110 is also formed, which is surrounded by the battery cell 142 and the second electrical path 82. More specifically, a magnetic flux passage area S110 is formed, which is surrounded by the housing 142a, the second electrical path 82, the positive-side power terminal 171a, and the negative-side power terminal 171b.

[0278] At this time, Figure 29 When wiring is performed as shown, the magnetic flux passage area S110 becomes larger, and for the same reasons as in the first embodiment, the impedance measurement error may become larger. Therefore, in this modification example 1, it is desirable to minimize the size of the magnetic flux passage area S110. More specifically, it is desirable to set the size of the magnetic flux passage area S110 so that the error between the actual complex impedance of the battery cell 142 and the complex impedance calculated by the microcomputer unit 53 is within the range of ±1mΩ. In this modification example 1, when the battery capacity is 25Ah to 800Ah and the battery temperature is -10°C to 65°C, in order to calculate the zero crossing point, the size of the magnetic flux passage area S110 is set so that the error between the actual complex impedance of the battery cell 142 and the complex impedance calculated by the microcomputer unit 53 is within the range of ±170μΩ.

[0279] The actual complex impedance of the battery cell 142 refers to the value calculated when the magnetic flux passage area S110 is zero or as close to zero as possible, or the value obtained by quantifying and correcting the error (the influence of the wiring shape on the induced electromotive force) caused by the magnetic flux passage area S110 using a predetermined mathematical formula. Alternatively, the four-terminal method or the four-terminal pair method may be used. The error in the complex impedance refers to any error in the absolute value, real part, or imaginary part of the complex impedance.

[0280] Furthermore, in Modification 1, the size of the magnetic flux passage area S110 is also set so that the induced electromotive force generated in the second electrical path 82 based on the AC signal I flowing through the first electrical path 81 is within the permissible electromotive force value range including zero. Specifically, the size of the magnetic flux passage area S110 and the relative position of the first electrical path 81 and the magnetic flux passage area S110 are set so that the induced electromotive force is within the permissible electromotive force value range.

[0281] At this time, in this modification 1, if Figure 30 Perform wiring as shown. Figure 30As shown, the second electrical path A 82a and the second electrical path B 82b connected to the ASIC unit 50a are routed parallel to each other to a predetermined branch point Br11. Specifically, the second electrical path A 82a and the second electrical path B 82b are routed in parallel with each other, with minimal gaps between them. Furthermore, any routing method is acceptable as long as the second electrical path A 82a and the second electrical path B 82b are routed parallel to each other. Furthermore, the second electrical path A 82a and the second electrical path B 82b may be twisted together once or multiple times from the ASIC unit 50a to the branch point Br11.

[0282] The branch point Br11 is located further outboard of the front end of the positive-side power supply terminal 171a in the longitudinal direction of the battery cell 142. The second A electrical path 82a is routed from the branch point Br11 toward the positive-side power supply terminal 171a, while the second B electrical path 82b is routed from the branch point Br11 toward the negative-side power supply terminal 171b.

[0283] More specifically, the second A electric path 82a extends linearly in the longitudinal direction from the branch point Br11 to just above the positive power terminal 171a and bends therefrom to extend in the longitudinal direction toward the positive power terminal 171a.

[0284] Meanwhile, the second B electrical path 82b extends longitudinally from the branch point Br11 along the outer circumference of the housing case 142a, bends at the end of the battery cell 142 (the end facing the negative-side power supply terminal 171b), and connects to the negative-side power supply terminal 171b. This second B electrical path 82b is preferably wired so as to abut against the housing case 142a. It goes without saying that the second B electrical path 82b is insulated from the housing case 142a.

[0285] Furthermore, the first A electrical path 81a and the first B electrical path 81b connected to the current modulation circuit 56 are routed parallel to each other to a predetermined modulation line branch point Br12. Specifically, the first A electrical path 81a and the first B electrical path 81b are routed parallel to each other with minimal gaps. Furthermore, any routing method is acceptable as long as the first A electrical path 81a and the first B electrical path 81b are routed parallel to each other.

[0286] The branch point Br12 is located outside the negative power supply terminal 171b (the end of the battery cell 142 on the negative power supply terminal 171b side) in the longitudinal direction of the battery cell 142. The first A electrical path 81a is routed from the branch point Br12 toward the positive power supply terminal 171a, while the first B electrical path 81b is routed from the branch point Br12 toward the negative power supply terminal 171b.

[0287] More specifically, first electrical path A 81a extends longitudinally from branch point Br12 along the outer circumference of housing case 142a, bends at the end of battery cell 142, and connects to positive-side power terminal 171a. Needless to say, first electrical path A 81a is insulated from housing case 142a. First electrical path B 81b bends longitudinally from branch point Br12 toward negative-side power terminal 171b.

[0288] Furthermore, the wiring of the first electrical path 81 and the second electrical path 82 is fixed. Specifically, the size of the magnetic flux passage area S110 and the relative position of the first electrical path 81 and the magnetic flux passage area S10 are set (fixed) so that the error between the actual complex impedance of the battery cell 142 and the complex impedance calculated by the microcomputer unit 53 is within a range of ±1 mΩ (more preferably, ±170 μΩ).

[0289] In addition, in this variant example 1, as long as the distance between the branch point Br11 and the front end of the positive side power supply terminal 171a is set so that the error between the actual complex impedance of the battery cell 142 and the complex impedance calculated by the microcomputer unit 53 is within the range of ±1mΩ (more preferably ±170μΩ), it can be set arbitrarily.

[0290] The distance between the branch point Br12 and the negative power supply terminal 171b can be arbitrarily set as long as the error between the actual complex impedance of the battery cell 142 and the complex impedance calculated by the microcomputer unit 53 is within the range of ±1 mΩ (more preferably ±170 μΩ).

[0291] According to this modification example 1, the following effects can be achieved.

[0292] The size of the magnetic flux passage area S110 is set so that the error between the actual complex impedance of the battery cell 142 and the complex impedance calculated by the microcomputer unit 53 is within a range of ±1 mΩ. In this first modification, when the battery capacity is set within the range of 25 Ah to 800 Ah and the battery temperature is between -10°C and 65°C, the size of the magnetic flux passage area S110 is set so that the error between the actual complex impedance of the battery cell 142 and the complex impedance calculated by the microcomputer unit 53 is within a range of ±170 μΩ. This can suppress errors in complex impedance measurement.

[0293] Furthermore, the branch point Br11 of the second electrical path 82 is positioned further outward from the front end of the positive-side power terminal 171a in the longitudinal direction. The second A electrical path 82a is then routed from this branch point Br11 toward the positive-side power terminal 171a, while the second B electrical path 82b is routed from this branch point Br11 toward the negative-side power terminal 171b. More specifically, the second A electrical path 82a extends linearly from the branch point Br11 in the longitudinal direction to directly above the positive-side power terminal 171a, and from there, bends in a manner extending longitudinally toward the positive-side power terminal 171a. Meanwhile, the second B electrical path 82b is formed so as to extend longitudinally from the branch point Br11 along the outer circumferential surface of the housing 142a, bend at the end of the battery cell 42 (the end on the negative-side power terminal 171b side), and connect to the negative-side power terminal 171b. This makes it easy to set the size of the magnetic flux passage area S110 as described above.

[0294] Furthermore, the branch point Br12 of the first electrical path 81 is positioned outboard of the negative-side power supply terminal 171b (the end of the battery cell 42 on the negative-side power supply terminal 171b side) in the longitudinal direction of the battery cell 142. In other words, it is located on the opposite side of the branch point Br11. This increases the distance between the modulation line through which the AC signal I flows and the magnetic flux passage area S110. This reduces the induced electromotive force and suppresses measurement errors.

[0295] Furthermore, from the ASIC unit 50a to the branch point Br11, the second electrical path A 82a and the second electrical path B 82b are routed alongside each other with minimal gaps. This reduces errors in complex impedance measurement. Furthermore, by twisting the second electrical path A 82a and the second electrical path B 82b one or more times from the ASIC unit 50a to the branch point Br11, errors can be further reduced.

[0296] (Variation 2)

[0297] like Figure 31As shown in FIG. 1 , a part of the structure of the above-mentioned modification example 1 may be changed as follows. Figure 31 As shown by the dashed line, the second electrical path B 82b extends from the branch point Br11 through the interior of the housing case 142a and along the longitudinal direction from the end of the housing case 142a to the end thereof. The second electrical path B 82b then bends at the end of the battery cell 142 (the end on the negative-side power supply terminal 171b side) and connects to the negative-side power supply terminal 171b. It goes without saying that the second electrical path B 82b is covered by an insulating film or the like and is insulated from the housing case 142a and the like.

[0298] Likewise, if Figure 31 As shown by the dashed line, the first electrical path A 81a extends from branch point Br12 through the interior of the housing case 142a and along its longitudinal direction from the end of the housing case 142a to the end thereof. The first electrical path A 81a then bends at the end of the battery cell 142 (the end facing the positive-side power supply terminal 171a) and connects to the positive-side power supply terminal 171a. It goes without saying that the first electrical path A 81a is covered with an insulating film or the like and is insulated from the housing case 142a and the like.

[0299] This makes it possible to easily reduce the magnetic flux passage area S110 surrounded by the battery cell 142 and the second electrical path 82. Furthermore, since part of the wiring is routed inside the housing case 142a, it is possible to prevent the wiring from becoming an obstruction.

[0300] (Variation 3)

[0301] like Figures 32 to 35 As shown in FIG. 1 , a part of the structure of the above-mentioned modification example 1 may be modified as follows. That is, circuit substrates 801 and 802 are respectively arranged at both ends of the longitudinal direction of the battery pack 140. Figure 32 As shown, the circuit substrate 801 is arranged in such a manner as to contact the upper surface of the battery cell 142. Specifically, the circuit substrate 801 is arranged in such a manner that the positive side power supply terminal 171a of the battery cell 142 arranged in the first row (four rows) on the inner side contacts the circuit substrate 801. Figure 33 (a) Figure 34 As shown in (a), the positive side power supply terminal 171a of the battery cell 142 in the first column is connected to the second A electric path 82a wired on the circuit board 801. Figure 34 (a) is a top view showing a portion of the circuit substrate 801. Figure 34 (b) is a side view showing a portion of the battery cell 142 in the first column.

[0302] In addition, if Figure 33As shown in (b) of FIG. 17, the housing 142a is formed so that its outer edge protrudes in the long direction (i.e., the protruding direction of the positive-side power terminal 171a) at the end portion on the positive-side power terminal 171a side of the battery cell 142. That is, as shown in (b) of FIG. 17, the protruding portion 803 is formed in the housing 142a so as to surround the positive-side power terminal 171a. That is, in the long direction, the protruding portion 803, which is the end portion of the housing 142a on the positive-side power terminal 171a side, is formed so as to be at the same position (height) as the front end of the positive-side power terminal 171a. In addition, the housing 142a and the positive-side power terminal 171a are insulated by an insulating member. The protruding portion 803 is formed so as to protrude to the same extent as the positive-side power terminal 171a and to contact the circuit board 801. Figure 33 As shown in (b) of FIG. 17, the protruding portion 803 contacts the circuit board 801, and the second B electrical path 82b of the wiring of the circuit board 801 is connected to the negative-side power terminal 171b via the protruding portion 803 and the housing 142a.

[0303] Furthermore, the housing 142a is connected to (in this modification, integrated with) the negative-side power terminal 171b. As shown in (b) of FIG. 17, Figure 33 (b) of FIG. 17, Figure 34 As shown in (b) of FIG. 17, the protruding portion 803 contacts the circuit board 801, and the second B electrical path 82b of the wiring of the circuit board 801 is connected to the negative-side power terminal 171b via the protruding portion 803 and the housing 142a.

[0304] In addition, the circuit board 801 is disposed so as to contact the upper surface side in the long direction of the battery cell 142 of the second column (three columns) disposed on the front side. At this time, the negative-side power terminal 171b of the battery cell 142 of the second column contacts the circuit board 801.

[0305] On the other hand, as shown in (b) of FIG. 17, Figure 32 The circuit board 802 is disposed so as to contact the lower surface of the battery cell 142. The structure of this circuit board 802 is the same as that of the circuit board 801, and thus detailed description is omitted. In addition, Figure 34 (c) of FIG. 17 is a side view of the battery cell 142 of the second column, Figure 34 (d) of FIG. 17 is a plan view of a portion of the circuit board 802.

[0306] In the circuit boards 801, 802, an ASIC portion 50a, not shown, is disposed, and from the ASIC portion 50a to the branch point Br11, as shown in (a) of FIG. 17, Figure 33 (a) of FIG. 17, Figure 34 (a) of FIG. 17, Figure 34As shown in (d), the second electrical path A 82a and the second electrical path B 82b are routed parallel to each other. That is, the second electrical path A 82a and the second electrical path B 82b are routed in parallel with as little gap as possible. Alternatively, the second electrical path A 82a and the second electrical path B 82b may be routed so as to intersect and be twisted one or more times from the ASIC unit 50a to the branch point Br11.

[0307] Then, the second B electrical path 82b is connected to the protrusion 803 just above the protrusion 803, thus completing the wiring. Meanwhile, the second A electrical path 82a continues as is and is connected to the positive power supply terminal 171a just above the positive power supply terminal 171a, thus completing the wiring.

[0308] Therefore, if Figure 33 (a) Figure 34 (a) Figure 34 As shown in (d), the branch point Br11 in the modification 3 is located near the terminal end of the second B electrical path 82b (the connection portion with the protrusion 803). Therefore, the magnetic flux passing area S110 surrounded by the battery cell 142 and the second electrical path 82 is as shown in FIG. Figure 33 The magnetic flux passing region S110 is set so that the error between the actual complex impedance of the battery cell 142 and the complex impedance calculated by the microcomputer unit 53 is within a range of ±1 mΩ (more preferably ±170 μΩ).

[0309] Furthermore, the branch point Br11 is located outside the front end of the positive power terminal 171a in the longitudinal direction, similarly to Modification 1. The second A electric path 82a is routed from the branch point Br11 toward the positive power terminal 171a.

[0310] In addition, if Figure 32 、 Figure 35 As shown, to connect the battery cells 142 in series, busbars 173 connect the positive-side power terminals 171a and the negative-side power terminals 171b of adjacent columns via circuit boards 801 and 802. Each busbar 173 is disposed on circuit boards 801 and 802 on opposite sides of the battery cells 142. Alternatively, each busbar 173 may be wired on circuit boards 801 and 802. Although not shown, the first electrical path 81 may also be wired on circuit boards 801 and 802.

[0311] According to Modification 3, since the second electrical path 82 is wired to the circuit boards 801 and 802, it is easy to set the magnetic flux passage area S110 surrounded by the second electrical path 82 and the battery cell 142 to a constant area.

[0312] Furthermore, when the first electrical path 81 is wired to the circuit boards 801 and 802, the positional relationship between the modulation line through which the AC signal I flows and the magnetic flux passage area S110 can be fixed. Therefore, impedance variations can be suppressed as designed. Furthermore, wiring to the circuit boards 801 and 802 simplifies wiring and assembly.

[0313] Furthermore, in the third modification, the wiring pattern of the second electrical path 82 can also be arbitrarily changed. Figure 36 As shown in (a), a circular wiring pattern of the second B electrical path 82b can also be provided along the protrusion 803. Thus, the connection between the second B electrical path 82b and the protrusion 803 becomes easy. In this case, the busbar 173 is as shown in FIG. Figure 36 Just set it as shown in (b).

[0314] (Another example of modification)

[0315] In the above-mentioned Modifications 1 to 3, the positive and negative electrodes of the battery unit 142 may be replaced. In this case, in Modification 2, a portion of the second A electric path 82a is wired inside the housing case 142a.

[0316] In the above-mentioned modifications 1 and 2, the negative electrode may be connected to the housing case 142 a , and the second B electric path 82 b may be connected to the negative electrode of the battery cell 42 via the housing case 142 a .

[0317] In the above-mentioned Modifications 1 to 3, the first embodiment is used as the basic structure, but any of the above-mentioned Second to Tenth Embodiments and other embodiments may be used as the basic structure. In other words, the above-mentioned embodiments and the above-mentioned Modifications may be combined.

[0318] In the above-described embodiment and various variations, the permissible magnetic flux value range can be arbitrarily set, taking into account the required calculation accuracy, the magnitude of the response signal, and the noise signal. Furthermore, the permissible electromotive force value range can be arbitrarily set, taking into account the required calculation accuracy, the magnitude of the response signal, and the noise signal. For example, the permissible electromotive force value range can be set to a range of ±200 μV centered on zero.

[0319] In the above-mentioned variation, the positive-side power terminal 171a may not protrude. In this case, the positive-side power terminal 171a is insulated from the housing case 142a. Furthermore, in variation 3, when using a battery cell 142 in which the positive-side power terminal 171a does not protrude, the end of the housing case 142a on the positive-side power terminal 171a side can be positioned approximately flush with the positive-side power terminal in the longitudinal direction. This allows the circuit boards 801 and 802 to be positioned in contact with the positive-side power terminal 171a and the end of the housing case 142a on the positive-side power terminal side.

[0320] In the above-mentioned embodiment and modification, the battery measuring device 50 may also measure the impedance of the battery cells 42, 142 (battery module) connected in parallel. That is, in order to increase the battery capacity, a plurality of battery cells 42, 142 may be connected in parallel and aggregated into one unit (battery module). In this case, in order to measure the impedance of the battery module connected in parallel as a unit as a whole, the range shown in the present disclosure is applied to the above-mentioned one unit (battery module) with respect to the numerical range of the battery capacity and the impedance error. That is, the magnetic flux passing regions S10 and S110 may be set in such a manner that the error of the impedance of the battery module connected in parallel as a unit as a whole is within the range of ±1mΩ. In addition, if the battery capacity of the battery module connected in parallel as a unit is 25Ah to 800Ah and the battery temperature is -10°C to 65°C, it is more desirable to set the magnetic flux passing regions S10 and S110 in such a manner that the error of the impedance is within the range of ±170μΩ.

[0321] Similarly, the battery measurement device 50 can also measure the impedance of a battery module (battery cell 42, 142) connected in series. That is, multiple battery cells 42, 142 can be connected in series and grouped together as a single unit (battery module). In this case, when measuring the impedance of the entire battery module connected in series as a single unit, the range associated with the battery capacity applies to each battery cell 42, 142 connected in series, while the range of the impedance error value applies only to the total number of battery cells 42, 142 connected in series.

[0322] For example, a battery module having five battery cells 42, 142 connected in series is regarded as one unit. When measuring the impedance, if the battery capacities of the battery cells 42, 142 constituting the battery module are 25Ah to 800Ah, respectively, it is expected that the magnetic flux passing areas S10, S110 are set so that the impedance error is within the range of ±170μΩ×5=±850μΩ.

[0323] In addition, in the case of series connection, one battery cell 42 , 142 constituting the battery module may be replaced with a battery cell in which a plurality of battery cells 42 , 142 are connected in parallel.

[0324] The disclosure in this specification is not limited to the illustrated embodiments. The present disclosure includes the illustrated embodiments and variations made thereon by those skilled in the art. For example, the present disclosure is not limited to the combination of components and / or elements shown in the embodiments. The present disclosure can be implemented in various combinations. The present disclosure may have additional parts that can be added to the embodiments. The present disclosure includes embodiments in which components and / or elements of the embodiments are omitted. The present disclosure includes substitutions or combinations of components and / or elements between one embodiment and another. The disclosed technical scope is not limited to the description of the embodiments. The disclosed several technical scopes should be understood to be represented by the description of the claims, and also include all variations within the meaning and scope equivalent to the description of the claims.

[0325] The control unit and the method of the control unit described in the present disclosure may also be implemented by a special-purpose computer, which is provided by constituting a processor and a memory, and the above-mentioned processor is programmed to perform one or more functions embodied by a computer program. Alternatively, the control unit and the method of the control unit described in the present disclosure may be implemented by a special-purpose computer, which is provided by constituting a processor by one or more special-purpose hardware logic circuits. Alternatively, the control unit and the method of the control unit described in the present disclosure may be implemented by one or more special-purpose computers, which are constituted by a combination of a processor and a memory programmed to perform one or more functions and a processor constituted by one or more hardware logic circuits. Moreover, the computer program may also be stored in a computer-readable non-temporary tangible storage medium as an instruction executed by a computer.

[0326] While the present disclosure has been described based on embodiments, it should be understood that the present disclosure is not limited to the aforementioned embodiments and configurations. The present disclosure also encompasses various modifications and variations within the scope of equivalents. Furthermore, various combinations and configurations, including combinations and configurations involving only one element, more than one element, or less than one element, also fall within the scope and spirit of the present disclosure.

Claims

1. A battery measuring device for measuring a battery state. The battery measuring device comprises: a signal control unit provided on a first electrical path connecting the positive power supply terminal and the negative power supply terminal of the battery, configured to output a predetermined AC signal from the battery or input a predetermined AC signal to the battery; a response signal input unit provided on a second electrical path connecting the positive-side power supply terminal and the negative-side power supply terminal, and inputting a response signal of the battery in response to the AC signal via the second electrical path; a calculation unit configured to calculate information related to the complex impedance of the battery based on the response signal; as well as a circuit substrate for fixing the first electrical path and the second electrical path; The relative positions of the first electrical path and the second electrical path are fixed, The relative positions of the first electrical path and the second electrical path relative to the positive-side power supply terminal and the negative-side power supply terminal are fixed. The positive-side power terminal and the negative-side power terminal protrude from the upper surface of the battery. The circuit substrate is located between the front ends of the positive power terminal and the negative power terminal and the upper surface in the protruding direction of the positive power terminal and the negative power terminal. The second electrical path includes: a positive side detection line connecting the positive side power supply terminal and the response signal input unit; and a negative side detection line connecting the negative side power supply terminal and the response signal input unit. The positive electrode side detection line and the negative electrode side detection line are arranged to branch off from each other at a predetermined branch point from the response signal input unit. The positive electrode side detection line is wired in the circuit substrate so as to cross the negative electrode side detection line once or multiple times between the response signal input unit and the branch point. The positive side detection line and the negative side detection line are fixed to the circuit substrate between the response signal input unit and the branch point in such a way that a magnetic flux passage area formed by the intersection of the positive side detection line and the negative side detection line is fixed on the circuit substrate.

2. The battery measuring device according to claim 1, wherein The magnetic flux passage area formed by the intersection of the positive side detection line and the negative side detection line includes a first magnetic flux passage area and a second magnetic flux passage area in which the generated induced electromotive forces have different phases. The positive-side detection line and the negative-side detection line are fixed to the circuit board between the response signal input portion and the branch point so that the first magnetic flux passage region and the second magnetic flux passage region have the same area.

3. The battery measuring device according to claim 2, wherein: The number of the first magnetic flux passing areas and the number of the second magnetic flux passing areas are equal.

4. The battery measuring device according to any one of claims 1 to 3, wherein The circuit substrate is located between the positive-side power terminal and the negative-side power terminal in the arrangement direction of the positive-side power terminal and the negative-side power terminal.

5. The battery measuring device according to any one of claims 1 to 3, wherein In the circuit substrate, a dielectric is interposed between the first electric path and the second electric path.

6. The battery measuring device according to claim 5, wherein: In the circuit substrate, the dielectric is provided at an intersection where the first electrical path and the second electrical path intersect.

7. The battery measuring device according to any one of claims 1 to 3, wherein: In the circuit substrate, the first electric path and the second electric path are arranged so as not to directly intersect each other.

8. The battery measuring device according to any one of claims 1 to 3, wherein In the circuit substrate, the first electrical path and the second electrical path are arranged on different surfaces.

9. The battery measuring device according to any one of claims 1 to 3, wherein: At least one of the first electrical path and the second electrical path is wired along the upper surface of the battery.

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