Battery impedance measuring device

Abstract

The objective of this invention is to perform highly accurate evaluation of batteries using a simple method. [Solution] The control unit 12 performs first mode and second mode operations, respectively, in which the operation of the first switch SW1 corresponding to the first resonant circuit Rs1 and the operation of the second switch SW2 corresponding to the second resonant circuit Rs2 are different. Based on the damped oscillation waveform of the first resonant circuit Rs1 when operating in first mode, the damped oscillation waveform of the first resonant circuit Rs1 when operating in second mode, and the damped oscillation waveform of the second resonant circuit Rs2 when operating in second mode, the control unit 12 determines the internal impedance of the battery 10.

Description

[Technical Field]

[0001] The present invention relates to a battery impedance measuring device, and more particularly to a device for measuring the internal impedance of a battery using a resonant circuit. [Background technology]

[0002] Electric vehicles and hybrid vehicles are equipped with rechargeable batteries (hereinafter simply referred to as batteries) that can be repeatedly charged and discharged. Solar power generation systems also have batteries to store the electrical energy they generate. During the manufacturing process, these batteries are evaluated for their performance and for any defects. Evaluation indicators include, for example, internal impedance and metal deposition amount.

[0003] Regarding technologies for evaluating batteries, Patent Document 1 describes a technique for measuring changes in impedance in response to changes in frequency. Patent Document 2 describes a battery tester. In this battery tester, the voltage generated at both terminals of the battery by the alternating current supplied to the battery is measured, and the internal impedance of the battery is determined based on the alternating current and the measured voltage. Patent Document 3 describes a four-wire impedance measuring device having a pair of source terminals (current supply terminals) and sense terminals (voltage detection terminals) connected to the sample to be measured. The equivalent series resistance of a battery is described as the sample to be measured. Patent Document 4 describes a detection device for detecting the state of a lithium-ion secondary battery. This detection device has one or more resonant circuits that apply one or more specific frequency vibrations to a lithium-ion secondary battery, and includes a detection unit that measures the damping characteristics of one or more resonant currents and outputs them as detection signals. The detection device further includes a control unit that uses the damping characteristic detection signal obtained from the detection unit to detect at least one of lithium deposition and the presence of foreign metals inside the lithium-ion secondary battery. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2018-179652 [Patent Document 2] Japanese Patent Publication No. 2023-32275 [Patent Document 3] Japanese Patent Publication No. 2006-322821 [Patent Document 4] Japanese Patent Publication No. 2023-182 [Patent Document 5] Japanese Patent Publication No. 2023-110285 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Methods for measuring the internal impedance of a battery include determining the internal impedance from the relationship between the sinusoidal voltage applied to the battery and the sinusoidal current flowing through the battery, as described in Patent Documents 1 to 3. Furthermore, as described in Patent Document 3, there is a method to improve measurement accuracy by measuring the internal impedance of the battery after compensating for the contact resistance between the battery electrodes. However, these methods require a high-precision sinusoidal wave generator, which can make the measurement equipment complex.

[0006] The objective of this invention is to perform highly accurate evaluation of batteries using a simple method. [Means for solving the problem]

[0007] The battery impedance measuring device according to the present invention comprises: a plurality of resonant circuits through which a resonant current flows in a battery to be measured; a waveform acquisition unit that acquires a damped oscillation waveform of the current flowing through each of the resonant circuits; a control unit that determines the internal impedance of the battery based on the damped oscillation waveform acquired for each of the resonant circuits; and a switch controlled by the control unit and provided corresponding to each of the resonant circuits, the switch provided between the corresponding resonant circuit and the battery, wherein the control unit determines the internal impedance based on a plurality of damped oscillation waveforms for each of the resonant circuits acquired for a plurality of different combinations of switch operations.

[0008] In one embodiment, one end of each resonant circuit is individually in contact with the positive or negative electrode of the battery, and the control unit determines the contact resistance between one end of each resonant circuit and the battery, in addition to the internal impedance, based on multiple damped oscillation waveforms for each resonant circuit obtained for multiple switching operations with different combinations of switch operations.

[0009] In one embodiment, the control unit obtains a composite time waveform by combining the damped oscillation waveforms for each of the resonant circuits, and determines the internal impedance based on the composite time waveform.

[0010] In one embodiment, the control unit determines the internal impedance based on the degree to which multiple damped oscillation waveforms for each resonant circuit are attenuated, obtained for multiple different combinations of switch operations where each switch operates differently.

[0011] In one embodiment, the battery is supplied with a plurality of resonant circuits, including a first resonant circuit and a second resonant circuit, and the control unit performs first mode and second mode operations, respectively, in which the operation of a first switch corresponding to the first resonant circuit and the operation of a second switch corresponding to the second resonant circuit are different, and the internal impedance is determined based on the damped oscillation waveform of the first resonant circuit when operating in the first mode, the damped oscillation waveform of the first resonant circuit when operating in the second mode, and the damped oscillation waveform of the second resonant circuit when operating in the second mode.

[0012] In one embodiment, one end of the first resonant circuit and one end of the second resonant circuit are in contact with the positive or negative electrode of the battery, respectively, and the control unit determines, in addition to the internal impedance, the contact resistance between one end of the first resonant circuit and the battery and the contact resistance between one end of the second resonant circuit and the battery, based on the damped oscillation waveform of the first resonant circuit when operating in the first mode, the damped oscillation waveform of the first resonant circuit when operating in the second mode, and the damped oscillation waveform of the second resonant circuit when operating in the second mode.

[0013] In one embodiment, the control unit determines the internal impedance based on the damped oscillation waveform of the first resonant circuit when operating in the first mode, and the combined time waveform when operating in the second mode, which is a combined time waveform obtained by combining the damped oscillation waveform of the first resonant circuit and the damped oscillation waveform of the second resonant circuit.

[0014] In one embodiment, the control unit determines the internal impedance based on the degree to which the damped oscillation waveform of the first resonant circuit is attenuated and the degree to which the composite time waveform is attenuated when operating in the first mode.

[0015] In one embodiment, the first mode is an operating mode in which, when the first switch corresponding to the first resonant circuit and the second switch corresponding to the second resonant circuit are in the off state, the first switch is turned on and the second switch is kept in the off state, and the second mode is an operating mode in which, when the first switch is off and the second switch is on, the first switch is turned on and the second switch is kept in the on state.

[0016] In one embodiment, the first mode is an operating mode in which, when the first switch corresponding to the first resonant circuit and the second switch corresponding to the second resonant circuit are in the off state, the first switch is turned on and the second switch is kept off; and the second mode is an operating mode in which, when the first switch is on and the second switch is off, the first switch is kept on and the second switch is turned on from off. [Effects of the Invention]

[0017] According to the present invention, batteries can be evaluated with high accuracy using a simple method. [Brief explanation of the drawing]

[0018] [Figure 1] This diagram shows the main components of an impedance measuring device. [Figure 2] This diagram shows an equivalent circuit to explain the measurement principle. [Figure 3] This diagram shows the status of the battery impedance measuring device in modes 1 through 4. [Figure 4] This figure shows the time waveforms of currents IL1 and m1. [Figure 5] This figure shows the time waveform of current IL1,m3. [Figure 6] This figure shows the time waveform of currents IL2 and m3. [Figure 7] This figure shows the time waveform of the summation current IP, which is the sum of currents IL1,m3 and IL2,m3. [Figure 8] This figure shows the time waveform of the subtracted current IM, which is obtained by subtracting IL2,m3 from the current IL1,m3. [Figure 9] This figure shows a first example configuration of a battery impedance measuring device. [Figure 10] This figure shows a first modified example of a battery impedance measuring device. [Figure 11] This flowchart shows an example of the process performed by a battery impedance measuring device. [Figure 12] This figure shows a second modified example of a battery impedance measuring device. [Figure 13] This figure shows a second example configuration of a battery impedance measuring device. [Figure 14A] This diagram shows the state in each operating mode from Mode 5 to Mode 8. [Figure 14B] This diagram shows the status in each operating mode from Mode 9 to Mode 12. [Figure 14C] This diagram shows the status in each operating mode from Mode 13 to Mode 16. [Modes for carrying out the invention]

[0019] Embodiments of the present invention will be described with reference to the figures. The same components shown in multiple drawings are denoted by the same reference numerals, and their descriptions are simplified. Unless otherwise specified, terms indicating directions such as up, down, left, and right refer to the directions in the drawings.

[0020] Figure 1 shows the main components (main parts) of a battery impedance measuring device 100 according to an embodiment of the present invention. The battery impedance measuring device 100 includes a first resonant circuit Rs1, a first switch SW1, a second resonant circuit Rs2, a second switch SW2, and a first positive terminal T 1p , second positive terminal T 2p , first negative terminal T 1n , second negative terminal T 2nand a control unit 12. The control unit 12 may be constituted by a processor as hardware that controls the battery impedance measurement device 100 by executing a program.

[0021] The battery 10 to be measured is detachable from the battery impedance measurement device 100. The positive electrode of the battery 10 to be measured is the first positive electrode terminal T 1p and the second positive electrode terminal T 2p and the negative electrode is the first negative electrode terminal T 1n and the second negative electrode terminal T 2n and is attached to the battery impedance measurement device 100 so as to be in contact therewith.

[0022] One end of the first resonance circuit Rs1 is connected to the first positive electrode terminal T 1p and the other end is connected to one end of the first switch SW1. The other end of the first switch SW1 is connected to the first negative electrode terminal T 1n and is connected thereto. One end of the second resonance circuit Rs2 is connected to the second positive electrode terminal T 2p and the other end is connected to one end of the second switch SW2. The other end of the second switch SW2 is connected to the second negative electrode terminal T 2n and is connected thereto.

[0023] The first resonance circuit Rs1 includes a first resonance inductor L res1 , a first resonance capacitor C res1 and a first discharge resistor R res1 . The first resonance inductor L res1 and the first resonance capacitor C res1 are connected in series. The first resonance capacitor C res1 and the first discharge resistor R res1 are connected in parallel. When no DC voltage is applied to the first discharge resistor R res1 , the charge is discharged from the first resonance capacitor C res1 to the first resonance capacitor C res1 .

[0024] The second resonance circuit Rs2 includes a second resonance inductor L res2 , a second resonance capacitor C res2and the second discharge resistor R res2 It is equipped with a second resonant inductor L res2 and the second resonant capacitor C res2 These are connected in series. Second resonant capacitor C res2 and the second discharge resistor R res2 These are connected in parallel. Second discharge resistor R res2 This includes a second resonant capacitor C res2 When no DC voltage is applied to the second resonant capacitor C res2 Electrical charge is discharged from it.

[0025] The first discharge resistance R in this embodiment res1 and the second discharge resistor R res2 The resistance value is large enough that it does not contribute to the measurement of the internal impedance of battery 10.

[0026] As described later, the battery impedance measuring device 100 causes a damped oscillation current to flow through the battery 10 by the control unit 12 controlling the first switch SW1 and the second switch SW2. The battery impedance measuring device 100 then supplies a first resonant inductor L from the battery 10. res1 and the second resonant inductor L res2 The damped oscillating current flowing through at least one of the components is measured, and the internal impedance of the battery 10 is measured based on the time waveform of the measured damped oscillating current.

[0027] Figure 2 shows an equivalent circuit illustrating the measurement principle of the internal impedance of battery 10. The first discharge resistor R shown in Figure 1 res1 and the second discharge resistor R res2 This is not shown in the equivalent circuit of Figure 2. First discharge resistor R res1 and the second discharge resistor R res2 This is because the resistance value is large enough that it does not contribute to the measurement of the internal impedance of battery 10.

[0028] In Figure 2, the battery 10 is connected in series with an internal inductor L b , internal resistance R b and voltage source V bThis is represented by the first positive terminal T. 1p The contact resistance between the battery 10 and the positive terminal is the contact resistance R. c1p As shown, the second positive terminal T 2p The contact resistance between the battery 10 and the positive terminal is the contact resistance R. c2p It is shown as follows: First positive terminal T 1p The contact resistance R c1p Replaced with the second positive terminal T 2p The contact resistance R c2p Because it was replaced, the first positive terminal T 1p and the second positive terminal T 2p The dashed line indicates the contact resistance R. c1p This is the first resonant inductor L res1 One end and the internal inductor L b Connected between one end and the other, with contact resistance R c2p This is the second resonant inductor L res2 One end and the internal inductor L b It is connected to one end of it.

[0029] 1st negative terminal T 1n The contact resistance between the battery 10 and the negative terminal is the contact resistance R. c1n As shown, the second negative terminal T 2n The contact resistance between the battery 10 and the negative terminal is the contact resistance R. c2n It is shown as follows: First negative terminal T 1n The contact resistance R c1n Replaced with the second negative terminal T 2n The contact resistance R c2n Because it was replaced, the first negative terminal T 1n and the second negative terminal T 2n The dashed line indicates the contact resistance R. c1n The lower end of the first switch SW1 and the voltage source V b It is connected between the negative terminal and the contact resistance R c2n The lower end of the second switch SW2 and the voltage source V b It is connected between the negative terminal and the negative terminal.

[0030] In this embodiment, the contact resistance R c1p ,R c1n ,R c2pand R c2n The respective resistance values of p are approximated to be equal to R. Also, the inductance of the first resonance inductor L res1 and the inductance of the second resonance inductor L res2 are equal, being L res . Also, the capacitance of the first resonance capacitor C res1 and the capacitance of the second resonance capacitor C res2 are equal, being C res . The resistance value of the first discharge resistor R res1 and the resistance value of the second discharge resistor R res2 are equal, being R res .

[0031] The current flowing through the first loop from the positive electrode of the voltage source V b , through the internal resistance R b , internal inductor L b , contact resistance R c1p , first resonance inductor L res1 , first resonance capacitor C res1 , first switch SW1 and contact resistance R c1n and returning to the negative electrode of the voltage source V b is defined as current I1.

[0032] The current flowing through the second loop from the positive electrode of the voltage source V b , through the internal resistance R b , internal inductor L b , contact resistance R c2p , second resonance inductor L res2 , second resonance capacitor C res2 , second switch SW2 and contact resistance R c2n and returning to the negative electrode of the voltage source V b is defined as current I2.

[0033] Contact resistance R c1p , first resonance inductor L res1 , first resonance capacitor C res1 , first switch SW1, contact resistance R c1n , contact resistance R c2n , second switch SW2, second resonance capacitor Cres2 , second resonant inductor L res2 and contact resistance R c2p The current flowing through the third loop, which passes through the three points in order, is defined as current I3.

[0034] The combined currents I1 and I3 flow from top to bottom in Figure 2 through the first resonant circuit Rs1. The current obtained by subtracting current I3 from current I2 flows from top to bottom in Figure 2 through the second resonant circuit Rs2. In addition, the combined currents I1 and I2 flow out from the negative terminal of battery 10, through the inside of battery 10, and out from the positive terminal of battery 10.

[0035] Figure 3 shows the state of the battery impedance measuring device 100 in relation to the operation of the first switch SW1 and the second switch SW2. Modes 1 to 4 are shown as operating modes for the first switch SW1 and the second switch SW2. Mode 1 is an operating mode in which, starting from a state where both the first switch SW1 and the second switch SW2 are off, the first switch SW1 is turned on and the second switch SW2 is kept off. Mode 2 is an operating mode in which, starting from a state where both the first switch SW1 and the second switch SW2 are off, the first switch SW1 is kept off and the second switch SW2 is turned on. Mode 3 is an operating mode in which, starting from a state where the first switch SW1 is off and the second switch SW2 is on, the first switch SW1 is turned on and the second switch SW2 is kept on. Mode 4 is an operating mode in which, starting from a state where the first switch SW1 is on and the second switch SW2 is off, the first switch SW1 is kept on and the second switch SW2 is turned on.

[0036] In this embodiment, the internal impedance of the battery 10 is measured by the operation of the battery impedance measuring device 100 in modes 1 and 3, or by the operation of the battery impedance measuring device 100 in modes 2 and 4. As described above, the contact resistance R c1p ,R c1n ,R c2p and R c2n (Hereafter, contact resistance Rc The resistance values ​​of the elements are equal, and the element constants of each element in the first resonant circuit Rs1 are equal to the element constants of each element in the second resonant circuit Rs2. That is, the circuits in Figures 1 and 2 are symmetrical. Therefore, the currents I1, I2, and I3 in modes 1 and 3 are the same as the currents I2, I1, and the reverse polarity current -I3 in modes 2 and 4. Thus, the operation in modes 1 and 3 is shown below.

[0037] In Mode 1 operation, the control unit 12 turns on the first switch SW1 and keeps the second switch SW2 off, starting from a state where both the first switch SW1 and the second switch SW2 are off. Because the second switch SW2 is kept off, only the current I1 in the first loop flows, and the first resonant inductor L res1 Current I flowing through L1,m1 This is equal to the current I1. Here, the subscripts "L1,m1" refer to the first resonant inductor L in mode 1 operation. res1 This means the current flowing through it. The same applies to the subscripts attached to each of the following variables. However, to clarify the notation, the subscript indicating the mode may be omitted.

[0038] Figure 4 shows the current I when mode 1 operation starts at time t=0. L1,m1 The time waveform is shown. As will be described later, current I L1,m1 The time waveform is from the voltage source V b Voltage V bat , internal resistance R b Resistance value R bat , internal inductor L b Inductance L bat and contact resistance R c Resistance value R p This results in a damped oscillation waveform determined by the element constants of each element included in the first resonant circuit Rs1.

[0039] The control unit 12 controls the current I L1,m1 The time t=t when the function reaches its maximum 1,m1 and t 2,m1 Current I L1,m1A value corresponding to the maximum value of (for example, current I L1,m1 (Values ​​proportional to the maximum value of each) are V p1,m1 and V p2,m1 It is measured as follows. The control unit 12 is V p1,m1 and V p2,m1 The specific configuration for measuring the current I will be described later. The control unit 12 controls the current I according to (Equation 1). L1,m1 Attenuation rate α 1,m1 We seek.

[0040]

number

[0041] In Mode 3 operation, the control unit 12 turns on the first switch SW1 and keeps the second switch SW2 on, starting from a state where the first switch SW1 is off and the second switch SW2 is on. Since both the first switch SW1 and the second switch SW2 are on, currents I1 in the first loop, I2 in the second loop, and I3 in the third loop flow. First resonant inductor L res1 Current I flowing through L1,m3 This is the sum of currents I1 and I3, and the second resonant inductor L res2 Current I flowing through L2,m3 This is the result of subtracting I3 from the current I2.

[0042] Figures 5 to 8 show the time waveforms of each current when mode 3 operation starts at time t=0. Figure 5 shows the first resonant inductor L in mode 3 operation. res1 Current I flowing through L1,m3 The time waveform is shown. Figure 6 shows the second resonant inductor L in the operation of mode 3. res2 Current I flowing through L2,m3 The time waveform is shown.

[0043] Figure 7 shows the combined time waveform, with current I L1,m3 and I L2,m3 The summation current I P The time waveform is shown. Figure 8 shows the combined time waveform of current IL1,m3 From I L2,m3 Subtracted current I M The time waveform is shown.

[0044] Adding current I P and subtract current I M The time waveform is from the voltage source V b Voltage V bat , internal resistance R b Resistance value R bat , internal inductor L b Inductance L bat and contact resistance R c Resistance value R p This results in a damped oscillation waveform determined by the element constants of each element included in the first resonant circuit Rs1 and the second resonant circuit Rs2, respectively.

[0045] The control unit 12 controls the summing current I P =I L1 +I L2 The time t=t when the function reaches its maximum 1,P and t 2,P Adding current I P A value corresponding to the maximum value (for example, the summing current I P (Values ​​proportional to the maximum value of each) are V p1,P and V p2,P It is measured as follows. The control unit 12 is V p1,P and V p2,P The specific configuration for obtaining this will be described later. The control unit 12 adds the current I according to (Equation 2). P Attenuation rate α 1,m3 We seek.

[0046]

number

[0047] Furthermore, the control unit 12 controls the subtraction current I M =I L1 -I L2 The time t=t when the function reaches its maximum 1,M and t 2,M Subtraction current I M A value corresponding to the maximum value (for example, subtraction current IM (Values ​​proportional to the maximum value of each) are V p1,M and V p2,M It is measured as follows. The control unit 12 is V p1,M and V p2,M The specific configuration for obtaining this will be described later. The control unit 12 subtracts current I according to (Equation 3). M Attenuation rate α 2,m3 We seek.

[0048]

number

[0049] The control unit 12 determines the attenuation rate α according to (Equation 1) to (Equation 3). 1,m1 ,α 1,m3 and α 2,m3 Applying this to the following equations (4) to (6), the internal impedance of the battery 10 is determined. That is, the control unit 12 calculates the internal resistance value R of the battery 10 based on equations (4) to (6). bat , contact resistance R c Resistance value R p and internal inductance L bat We will find the answer. The derivation of (Equation 4) to (Equation 6) will be described later.

[0050]

number

number

number

[0051] Here, L res This is the first resonant inductor L res1 and the second resonant inductor L res2 This is the inductance, and in this embodiment, it is a known value. Thus, in the battery impedance measuring device 100 according to this embodiment, the control unit 12 operates in mode 1 and controls the first resonant inductor L res1 Current I flowing throughL1 Measure the current I L1 Attenuation rate α 1,m1 The control unit 12 also determines the first resonant inductor L in mode 3 operation. res1 Current I flowing through L1 and the second resonant inductor L res2 Current I flowing through L2 The control unit 12 further determines the summing current I P =I L1 +I L2 Attenuation rate α 1,m3 Calculate the subtracted current I M =I L1 -I L2 Attenuation rate α 2,m3 We seek.

[0052] The control unit 12 controls the attenuation rate α 1,m1 ,α 1,m3 and α 2,m3 Applying this to equations (4) to (6) above, we obtain the internal resistance R of battery 10. bat , contact resistance R c Resistance value R p and the internal inductance L of the battery 10 bat We will find the constants (R) of battery 10. b and L b ) is the voltage source V of battery 10 b The measurement is performed using [a specific method], and does not require an AC power supply or the like. Therefore, the battery 10 can be evaluated with high accuracy using a simple method.

[0053] Next, the derivation process of (Equations 4) to (Equations 6) is shown. In Mode 1 operation, the first resonant inductor L res1 Current I flowing through L1,m1 It can be expressed by (number 7) to (number 10).

[0054]

number

number

number

number

[0055] Here, A 1,m1 is the voltage V bat , capacitance C res , inductance L res , internal inductance L bat and internal resistance value R bat It is expressed as a constant that does not depend on time t, where V is the voltage. bat The voltage source V in battery 10 is b This is the output voltage. Capacitance C res This is the first resonant capacitor C res1 and the second resonant capacitor C res2 This is the capacitance. Inductance L res This is the first resonant inductor L res1 and the second resonant inductor L res2 This is the inductance.

[0056] Next, the operation in mode 3 is shown. In mode 3 operation, the first resonant inductor L res1 Current I flowing through L1,m3 This can be expressed by (number 11) to (number 15).

[0057]

number

number

number

number

number

[0058] Here, if the design is such that both (Equation 16) and (Equation 17) hold true, then (Equation 18) will hold true.

[0059]

number

number

number

[0060] Each constant of battery 10 can be determined for the frequency obtained by dividing the angular frequency shown in (Equation 18) by 2π.

[0061] In Mode 3 operation, the second resonant inductor L res2 Current I flowing through L2,m3 This is represented by (number 19).

[0062]

number

[0063] First resonant inductor L res1 Current I flowing through L1,m3 And the second resonant inductor L res2 Current I flowing through L2,m3 The summation current I P It is expressed as (Equation 20). Also, the first resonant inductor L res1 Current I flowing through L1,m3 Therefore, the second resonant inductor L res2 Current I flowing through L2,m3 Subtracted current I M It can be expressed as (number 21).

[0064]

number

number

[0065] L bat ≪L res Lres By designing this, (equation 22) holds true.

[0066]

number

[0067] From (Equation 8), (Equation 12), and (Equation 22), (Equations 4) to (Equation 6) are derived. (Equations 4) to (Equation 6) represent the attenuation rate α. 1,m1 ,α 1,m3 ,α 2,m3 and inductance L res From there, the internal resistance R of battery 10 is bat , contact resistance R c Resistance value R p and the internal inductance L of the battery 10 bat This is the formula for finding [the value].

[0068] Figure 9 shows a battery impedance measuring device 102 as a first configuration example of the battery impedance measuring device 100. The battery impedance measuring device 102 includes a first resonant circuit Rs1, a first switch SW1, a second resonant circuit Rs2 and a second switch SW2, and a control unit 12, as well as a first pickup inductor L pick1 , 1st buffer amplifier 14, 2nd pickup inductor L pick2 It includes a second buffer amplifier 16, an adder circuit 18, a subtractor circuit 20, a selector circuit 22, and a peak hold circuit 24.

[0069] First pickup inductor L pick1 This is the first resonant inductor L res1 It connects to the first pickup inductor L. pick1 Both ends of the first buffer amplifier 14 are connected to the positive-phase terminal Tp and the negative-phase terminal Tn, which are a pair of input terminals of the first buffer amplifier 14. The output terminal of the first buffer amplifier 14 is connected to the adder circuit 18, the subtractor circuit 20, and the selector circuit 22.

[0070] First pickup inductor L pick1 At both ends are the first resonant inductor L res1A damped oscillation voltage appears corresponding to the damped oscillation current flowing through it. First pickup inductor L pick1 The phase of the damped oscillation voltage appearing at both ends of the first resonant inductor L res1 Even if the phase of the damped oscillation current flowing through is different, the damping rate is still the current I L1 This results in a value equivalent to the above. The first buffer amplifier 14 outputs a signal SIL1 corresponding to this damped oscillation voltage. Signal SIL1 is the first resonant inductor L res1 Current I flowing through L1 It has a damped vibration waveform equivalent to that of [another instrument].

[0071] Second pickup inductor L pick2 This is the second resonant inductor L res2 It connects to the second pickup inductor L. pick2 Both ends of the second buffer amplifier are connected to the positive-phase terminal Tp and the negative-phase terminal Tn, which are a pair of input terminals of the second buffer amplifier 16. The output terminal of the second buffer amplifier 16 is connected to the adder circuit 18, the subtractor circuit 20, and the selector circuit 22.

[0072] Second pickup inductor L pick2 At both ends are the second resonant inductors L res2 A damped oscillation voltage appears corresponding to the damped oscillation current flowing through it. Second pickup inductor L pick2 The phase of the damped oscillation voltage appearing across the second resonant inductor L res2 Even if the phase of the damped oscillation current flowing through is different, the damping rate is still the current I L2 This is equivalent to the value obtained. The second buffer amplifier 16 outputs a signal SIL2 corresponding to this damped oscillation voltage. The signal SIL2 is connected to the second resonant inductor L res2 Current I flowing through L2 It has a damped vibration waveform equivalent to that of [another instrument].

[0073] The adder circuit 18 outputs a signal SIP to the selector circuit 22, which is the sum of the signal SIL1 output from the first buffer amplifier 14 and the signal SIL2 output from the second buffer amplifier 16. The subtractor circuit 20 outputs a signal SIM to the selector circuit 22, which is the subtraction of the signal SIL2 output from the second buffer amplifier 16 from the signal SIL1 output from the first buffer amplifier 14.

[0074] The selector circuit 22 selects one of the output terminals of the first buffer amplifier 14, the second buffer amplifier 16, the summing circuit 18, or the subtraction circuit 20, according to the control of the control unit 12, and connects the selected output terminal to the input terminal of the peak hold circuit 24.

[0075] The peak hold circuit 24 acquires two local maximums of the signal Sout output from the selector circuit 22 that occur at different times, and outputs them to the control unit 12. The peak hold circuit 24 may be configured, for example, according to the technology described in Patent Document 5. The control unit 12 determines the attenuation rate of the signal Sout. The attenuation rate is obtained from the local maximum V acquired at a later time t2. p2 The maximum value V obtained at the previous time t1. p1 This is the value obtained by dividing the natural logarithm of the ratio by the time difference t2-t1.

[0076] The operation of the battery impedance measuring device 102 is described. In Mode 1 operation, the control unit 12 first turns off both the first switch SW1 and the second switch SW2, then turns the first switch SW1 from off to on, and keeps the second switch SW2 off.

[0077] The control unit 12 controls the selector circuit 22 so that the output terminal of the first buffer amplifier 14 is connected to the peak hold circuit 24. With the output terminal of the first buffer amplifier 14 connected to the peak hold circuit 24, the control unit 12 performs operation in mode 1 and, based on the two maximum values ​​output from the peak hold circuit 24, determines the attenuation rate α 1,m1 We seek.

[0078] The control unit 12 controls the selector circuit 22 so that the output terminal of the adder circuit 18 is connected to the peak hold circuit 24. With the output terminal of the adder circuit 18 connected to the peak hold circuit 24, the control unit 12 performs operation in mode 3 and, based on the two maximum values ​​output from the peak hold circuit 24, determines the attenuation rate α 1,m3 We seek.

[0079] The control unit 12 controls the selector circuit 22 so that the output terminal of the subtraction circuit 20 is connected to the peak hold circuit 24. With the output terminal of the subtraction circuit 20 connected to the peak hold circuit 24, the control unit 12 performs operation in mode 3 and, based on the two maximum values ​​output from the peak hold circuit 24, determines the attenuation rate α 2,m3 We seek.

[0080] The control unit 12 receives the attenuation rate α from the peak hold circuit 24. 1,m1 ,α 1,m3 and α 2,m3 Obtain the following, and based on (Equation 4) to (Equation 6) above, determine the internal resistance value R of battery 10. bat , contact resistance R c Resistance value R p and the internal inductance L of the battery 10 bat We seek.

[0081] Figure 10 shows a battery impedance measuring device 104 as the first modified example of the battery impedance measuring device 102 in Figure 9. The battery impedance measuring device 104 is modified by replacing the first buffer amplifier 14 and the second buffer amplifier 16 of the battery impedance measuring device 102 in Figure 9 from differential (balanced) types to unbalanced types. The input terminal of the first buffer amplifier 14S is connected to the first resonant inductor L res1 and the first resonant capacitor C res1 It is connected to the connection point. The input terminal of the second buffer amplifier 16S is connected to the second resonant inductor L res2 and the second resonant capacitor C res2 It is connected to the connection point. The first buffer amplifier 14S has a first resonant inductor L res1 Current I L1A voltage corresponding to the input is applied to the second buffer amplifier 16, and the second resonant inductor L res2 Current I L2 A voltage corresponding to the value is input.

[0082] The control unit 12 of the battery impedance measuring device 104 performs the same operation as the control unit 12 of the battery impedance measuring device 102 in Figure 6, and measures the internal resistance R of the battery 10. bat , contact resistance R c Resistance value R p and the internal inductance L of the battery 10 bat We seek.

[0083] Figure 11 shows a flowchart illustrating an example of the process performed by the battery impedance measuring devices 102 and 104. The control unit 12 first turns off the first switch SW1 and the second switch SW2 (S1). In this state, the battery 10 is installed in the battery impedance measuring devices (102, 104) (S2).

[0084] The control unit 12 determines whether the operating mode is mode 1 or mode 3 according to user operation or a predetermined program (S3). If the control unit 12 determines that it should operate in mode 1, it turns on the first switch SW1 (S4) and obtains the maximum value from the peak hold circuit 24 (S5).

[0085] The control unit 12 turns off the first switch SW1 (S6) and determines whether or not two local maximums were obtained at two different times (S7). If the control unit 12 determines that two local maximums were not obtained, it returns to step S4. If the control unit 12 determines that two local maximums were obtained, it determines whether operation in two operating modes was performed (S8). If the control unit 12 determines that operation in two operating modes was not performed, it returns to step S3.

[0086] If the control unit 12 determines in step S3 that it should operate in mode 3, it turns on the second switch SW2 (S9), and then turns on the first switch SW1 (S10). The control unit 12 obtains the maximum values ​​from the peak hold circuit 24 for each of the signals SIP output from the adder circuit 18 and SIM output from the subtractor circuit 20 (S11). The control unit 12 turns off the first switch SW1 (S12) and determines whether two maximum values ​​have been obtained for each of the signals SIP and SIM at two different times (S13). If the control unit 12 determines that two maximum values ​​have not been obtained for each of the signals SIP and SIM, it returns to step S10. If the control unit 12 determines that two maximum values ​​have been obtained, it turns off the second switch SW2 (S14) and proceeds to step S8.

[0087] If the control unit 12 determines in step S8 that operation in both operating modes has occurred, it calculates the internal impedance of the battery 10 (S15). After that, the battery 10 is removed from the battery impedance measuring device (102, 104), and the measurement is completed. If the control unit 12 determines that operation in both operating modes has not occurred, it returns to step S3.

[0088] This section describes the processing when using a combination of modes 1 and 3. When using a combination of modes 2 and 4, the processing is performed on the operating modes and switches specified by the numbers in parentheses in the flowchart of Figure 11.

[0089] Figure 12 shows a battery impedance measuring device 106 as a second modified example of the battery impedance measuring device 102 in Figure 9. The first pickup inductor L pick1 and the second pickup inductor L pick2 Each of these is the first resonant inductor L res1 and the second resonant inductor L res2 It combines with both of them.

[0090] First pickup inductor L pick1and the first resonant inductor L res1 The polarity of the coupling coefficient with current I L1 When the first pickup inductor L increases, pick1 The voltage applied to the first buffer amplifier 14 is set to be positive. The first pickup inductor L pick1 and the second resonant inductor L res2 The polarity of the coupling coefficient with current I L2 When the first pickup inductor L increases, pick1 The voltage applied to the first buffer amplifier 14 is set to be positive.

[0091] Second pickup inductor L pick2 and the first resonant inductor L res1 The polarity of the coupling coefficient with current I L1 When the second pickup inductor L increases, pick2 The voltage applied to the second buffer amplifier 16 is set to be positive. Second pickup inductor L pick2 and the second resonant inductor L res2 The polarity of the coupling coefficient with current I L2 When the second pickup inductor L increases, pick2 The voltage applied to the second buffer amplifier 16 is set to be negative.

[0092] Here, the voltages applied to the first buffer amplifier 14 and the second buffer amplifier 16 are the voltages at the positive-sequence terminal Tp, with the negative-sequence terminal Tn of the first buffer amplifier 14 and the second buffer amplifier 16 as the potential reference.

[0093] With this configuration, the first resonant inductor L res1 Current I flowing through L1 and the second resonant inductor L res2 Current I flowing through L2 A voltage corresponding to the combined current is output from the first buffer amplifier 14 as the first signal SA. Also, the first resonant inductor L res1 Current I flowing through L1From the second resonant inductor L res2 Current I flowing through L2 A voltage corresponding to the current after subtracting the above is output from the second buffer amplifier 16 as the second signal SS.

[0094] The operation of the battery impedance measuring device 106 is shown below. The control unit 12 performs mode 1 operation with the output terminal of the first buffer amplifier 14 or the second buffer amplifier 16 connected to the peak hold circuit 24. From the output terminal of the first buffer amplifier 14, the first resonant inductor L res1 Current I flowing through L1 A corresponding first signal SA is output to the peak hold circuit 24. The first resonant inductor L is also output from the output terminal of the second buffer amplifier 16. res1 Current I flowing through L1 A second signal SS corresponding to this is output to the peak hold circuit 24. Based on the two maximum values ​​output from the peak hold circuit 24, the control unit 12 determines the attenuation rate α 1,m1 We seek.

[0095] The control unit 12 controls the selector circuit 22 so that the output terminal of the first buffer amplifier 14 is connected to the peak hold circuit 24. The control unit 12 performs mode 3 operation with the output terminal of the first buffer amplifier 14 connected to the peak hold circuit 24. From the output terminal of the first buffer amplifier 14, the first resonant inductor L res1 Current I flowing through L1 and the second resonant inductor L res2 Current I flowing through L2 A first signal SA corresponding to the combined current is output to the peak hold circuit 24. The control unit 12 determines the attenuation rate α based on the two maximum values ​​output from the peak hold circuit 24. 1,m3 We seek.

[0096] The control unit 12 controls the selector circuit 22 so that the output terminal of the second buffer amplifier 16 is connected to the peak hold circuit 24. The control unit 12 performs mode 3 operation with the output terminal of the second buffer amplifier 16 connected to the peak hold circuit 24. From the output terminal of the first buffer amplifier 14, the first resonant inductor L res1 Current I flowing through L1 From the second resonant inductor L res2 Current I flowing through L2 A second signal SS corresponding to the current after subtracting is output to the peak hold circuit 24. Based on the two maximum values ​​output from the peak hold circuit 24, the control unit 12 calculates the attenuation rate α 2,m3 We seek.

[0097] The control unit 12 receives the attenuation rate α from the peak hold circuit 24. 1,m1 ,α 1,m3 and α 2,m3 Obtain the following, and based on (Equation 4) to (Equation 6) above, determine the internal resistance value R of battery 10. bat , contact resistance R c Resistance value R p and the internal inductance L of the battery 10 bat We seek.

[0098] Figure 13 shows a battery impedance measuring device 108 as a second configuration example of the battery impedance measuring device 100. In the battery impedance measuring device 108, a third capacitor switch block CS3 is connected in parallel to the first capacitor switch block CS1. The first capacitor switch block CS1 is connected to the first resonant capacitor C res1 , first discharge resistance R res1 The components consist of the first switch SW1 and the third capacitor switch block CS3, which is the third resonant capacitor C res3 , third discharge resistance R res3 The components consist of a third switch SW3 and a third resonant capacitor C. res3 The third switch SW3 is connected in series with the third resonant capacitor C res3 and the third discharge resistor R res3 They are connected in parallel.

[0099] Further, a fourth capacitor-switch block CS4 is connected in parallel to a second capacitor-switch block CS2. The second capacitor-switch block CS2 includes a second resonance capacitor C res2 , a second discharge resistor R res2 and a second switch SW2. The fourth capacitor-switch block CS4 includes a fourth resonance capacitor C res4 , a fourth discharge resistor R res4 and a fourth switch SW4. The fourth resonance capacitor C res4 and the fourth switch SW4 are connected in series, and the fourth resonance capacitor C res4 and the fourth discharge resistor R res4 are connected in parallel.

[0100] As described above, each element constant of the first resonance circuit Rs1 and each element constant of the second resonance circuit Rs are the same. In this configuration example, the capacitance of the third resonance capacitor C res3 and the capacitance of the fourth resonance capacitor C res4 are made the same. Further, the resistance value of the third discharge resistor R res3 and the resistance value of the fourth discharge resistor R res4 are also made the same.

[0101] The battery impedance measurement device 108 according to this configuration example operates in either an A-frequency operation or a B-frequency operation with different resonance frequencies. In the A-frequency operation, the first resonance capacitor C res1 and the second resonance capacitor C res2 are used for measuring the internal impedance of the battery 10. In the B-frequency operation, the third resonance capacitor C res3 and the fourth resonance capacitor C res4 are used for measuring the internal impedance.

[0102] In the A - frequency operation, the control unit 12 maintains the third switch SW3 and the fourth switch SW4 in the off state, and executes the operation of either mode 1 or mode 3 by switching the first switch SW1 and the second switch SW2. The control unit 12 obtains the attenuation rates α 1,m1 , α 1,m3 and α 2,m3 for the resonance frequency in the A - frequency operation, and determines the internal resistance value R bat , the contact resistance R c resistance value R p and the internal inductance L bat of the battery 10.

[0103] In the B - frequency operation, the control unit 12 maintains the first switch SW1 and the second switch SW2 in the off state, and executes the operation of either mode 1 or mode 3 by switching the third switch SW3 and the fourth switch SW4. That is, similar to the operation of switching the first switch SW1 in the A - frequency operation, the control unit 12 switches the third switch SW3 in the B - frequency operation. And, similar to the operation of switching the second switch SW2 in the A - frequency operation, the control unit 12 switches the fourth switch SW4 in the B - frequency operation.

[0104] The control unit 12 obtains the attenuation rates α 1,m1 , α 1,m3 and α 2,m3 for the resonance frequency in the B - frequency operation, and determines the internal resistance value R bat , the contact resistance R c resistance value R p and the internal inductance L bat of the battery 10.

[0105] According to the battery impedance measurement device 108, for each of the two different resonance frequencies, the internal resistance value R bat , the contact resistance R c resistance value R p and the internal inductance L bat of the battery 10 are determined.

[0106] In the battery impedance measuring devices 100, 102, 104, 106, and 108 according to embodiments of the present invention, the above describes the combined operation of modes 1 and 3, and the combined operation of modes 2 and 4. The internal impedance of the battery 10 may be measured by the combined operation of modes 1 and 4, and the combined operation of modes 2 and 3.

[0107] In operation combining modes 1 and 4, the polarity of the formula corresponding to (Equation 21) is reversed compared to operation combining modes 1 and 3, but (Equations 4) to (Equations 6) are still used. Similarly, in operation combining modes 2 and 3, the polarity of the formula corresponding to (Equation 21) is reversed compared to operation combining modes 2 and 4, but (Equations 4) to (Equations 6) are still used.

[0108] Furthermore, in addition to modes 1 to 4, modes 5 to 16 shown in Figures 14A to 14C are also possible operating modes for the battery impedance measuring devices 100, 102, 104, 106 and 108 according to the embodiment of the present invention. Of these operating modes, modes 5 to 7, 10, and 12 to 16 cannot be used to measure the internal impedance of the battery 10 because no current flows through the first resonant circuit Rs1 and the second resonant circuit Rs2.

[0109] Mode 8 may be used in place of Mode 1 or 2. Here, current I 1,m8 and current I 2,m8 They are equal, and the decay rate corresponding to (Equation 8) is expressed as (Equation 22).

[0110]

number

[0111] Furthermore, mode 9 may be used in place of mode 1, and mode 11 may be used in place of mode 2.

[0112] As described above, the battery impedance measuring device (100, 102, 104, 106, 108) according to the embodiment of the present invention includes a first resonant circuit Rs1 and a second resonant circuit Rs2 as a plurality of resonant circuits that supply a resonant current to the battery 10 to be measured.

[0113] The peak hold circuit 24 acquires the damped oscillation waveforms of the currents flowing through the first resonant circuit Rs1 and the second resonant circuit Rs2, and obtains the maximum values ​​at different times. The control unit 12 determines the internal impedance of the battery 10 based on the maximum values ​​at different times of the damped oscillation waveforms of the currents flowing through the first resonant circuit Rs1 and the second resonant circuit Rs2.

[0114] In this way, the peak hold circuit 24, which acts as a waveform acquisition unit, acquires the damped oscillation waveform of the current flowing through each resonant circuit, and the control unit 12 determines the internal impedance of the battery 10 based on the damped oscillation waveform acquired for each resonant circuit.

[0115] The battery impedance measuring devices (100, 102, 104, 106, 108) are provided with a first switch SW1 and a second switch SW2 as switches controlled by the control unit 12, corresponding to a plurality (two) of resonant circuits. Specifically, the battery impedance measuring devices (100, 102, 104, 106, 108) include a first switch SW1 provided corresponding to the first resonant circuit Rs1 and a second switch SW2 provided for the second resonant circuit Rs2. The first switch SW1 is provided between the first resonant circuit Rs1 and the battery 10, and the second switch SW2 is provided between the second resonant circuit Rs2 and the battery 10.

[0116] The control unit 12 determines the internal impedance of the battery 10 based on multiple damped oscillation waveforms for each resonant circuit, which are acquired in response to multiple different combinations of switch operations. In the battery impedance measuring device (100, 102, 104, 106, 108) according to the embodiment of the present invention, the combination of switch operations may be a combination of modes 1 and 3, or a combination of modes 2 and 4. Mode 8 may be used instead of mode 1 or 2. Mode 9 may be used instead of mode 1, and mode 11 may be used instead of mode 2.

[0117] The control unit 12 may determine multiple internal impedances of the battery 10 for multiple different combinations of switch operation. The control unit 12 determines multiple internal resistance values ​​R for multiple different combinations of switch operation. bat The mean, median, mode, and other statistical values ​​are used to determine the final internal resistance value R. bat The control unit 12 can determine the multiple resistance values ​​R obtained for multiple combinations of different switch operations. p The statistical value of the final contact resistance R c The control unit 12 can determine the multiple internal inductances L obtained for multiple combinations of different switch operations. bat The statistical value of the final internal inductance L bat You can calculate it as follows.

[0118] In the battery impedance measuring device (100, 102, 104, 106, 108) according to the embodiment of the present invention, one end of each resonant circuit is individually in contact with the positive or negative electrode of the battery 10. One end of the first resonant circuit Rs1 is connected to the first positive electrode terminal T. 1p Therefore, the end of the first switch SW1 opposite to the first resonant circuit Rs1 is the first negative terminal T. 1n Therefore, one end of the second resonant circuit Rs2 is connected to the second positive terminal T. 2p Therefore, the end of the second switch SW2 opposite to the second resonant circuit Rs2 is the second negative terminal T. 2n The positive terminal of battery 10 is the first positive terminal T. 1p and the second positive terminal T2p The negative terminal of battery 10 makes contact with the second negative terminal T. 2n and the second negative terminal T 2n It makes contact with the terminal. This allows the internal impedance of the battery 10 to be measured based on the four-terminal method.

[0119] Based on multiple damped oscillation waveforms for each resonant circuit, obtained for multiple different combinations of switch operations, the control unit 12 calculates the contact resistance R as the contact resistance value between one end of each resonant circuit and the battery 10, in addition to the internal impedance. c Resistance value R p We seek.

[0120] The control unit 12 obtains a combined time waveform by synthesizing the damped oscillation waveforms for each resonant circuit, and determines the internal impedance of the battery 10 based on the combined time waveform. The combined time waveform includes the first resonant inductor L res1 Current I flowing through L1 and the second resonant inductor L res2 Current I flowing through L2 The time waveform of the combined current, and current I L1 From current I L2 There is a time waveform of the current after subtracting [a certain factor].

[0121] The control unit 12 determines the internal impedance of the battery 10 based on the degree of attenuation of multiple damped oscillation waveforms for each resonant circuit, which are obtained for multiple different combinations of switch operations. The attenuation rate shown in (Equation 1) to (Equation 3) is used as the degree of attenuation of the damped oscillation waveform.

[0122] The control unit 12 executes operations in a first mode and a second mode in which the operation of the first switch SW1 corresponding to the first resonance circuit Rs1 and the operation of the second switch SW2 corresponding to the second resonance circuit Rs2 are different. The control unit 12 obtains the internal impedance of the battery 10 based on the damped oscillation waveform of the first resonance circuit Rs1 when operating in the first mode, the damped oscillation waveform of the first resonance circuit Rs1 when operating in the second mode, and the damped oscillation waveform of the second resonance circuit Rs2 when operating in the second mode.

[0123] The first mode and the second mode may be mode 1 and mode 3, respectively. Also, the first mode and the second mode may be mode 2 and mode 4, respectively.

[0124] The first mode and the second mode may be mode 1 and mode 4, respectively. Also, the first mode and the second mode may be mode 2 and mode 3, respectively.

[0125] Mode 8 may be used instead of mode 1 or 2. Also, mode 9 may be used instead of mode 1, and mode 11 may be used instead of mode 2.

[0126] [Configuration of the present invention] Configuration 1: A plurality of resonance circuits that pass a resonance current through a battery to be measured, A waveform acquisition unit that acquires the damped oscillation waveform of the current flowing through each of the resonance circuits, A control unit that obtains the internal impedance of the battery based on the damped oscillation waveforms acquired for each of the resonance circuits, A switch that is controlled by the control unit and provided corresponding to each of the resonance circuits, and is provided between the corresponding resonance circuit and the battery, The control unit is A battery impedance measurement device characterized by obtaining the internal impedance based on a plurality of damped oscillation waveforms for each of the resonance circuits, which are obtained for a plurality of switch operations in which combinations of operations of each of the switches are different. Configuration 2: The battery impedance measuring device described in Configuration 1, One end of each of the aforementioned resonant circuits is individually in contact with the positive or negative electrode of the battery. The control unit, A battery impedance measuring device characterized by determining the contact resistance value between one end of each resonant circuit and the battery, in addition to the internal impedance, based on multiple damped oscillation waveforms for each resonant circuit obtained for multiple switch operations with different combinations of switch operations. Configuration 3: A battery impedance measuring device according to configuration 1 or configuration 2, The control unit, A composite time waveform is obtained by combining the damped oscillation waveforms for each of the aforementioned resonant circuits. A battery impedance measuring device characterized by determining the internal impedance based on the aforementioned synthesized time waveform. Configuration 4: A battery impedance measuring device according to any one of configurations 1 to 3, The control unit, A battery impedance measuring device characterized by determining the internal impedance based on the degree of attenuation of multiple damped vibration waveforms for each resonant circuit, which are obtained for multiple different combinations of switch operations where each switch operates differently. Configuration 5: The battery impedance measuring device described in Configuration 1, The battery is supplied with a plurality of resonant circuits, including a first resonant circuit and a second resonant circuit, which supply a resonant current to the battery. The control unit, The operation of the first switch corresponding to the first resonant circuit and the operation of the second switch corresponding to the second resonant circuit are performed in different first and second modes, respectively. The damped oscillation waveform of the first resonant circuit when operating in the first mode, The damped oscillation waveform of the first resonant circuit when operating in the second mode, The damped oscillation waveform of the second resonant circuit when operating in the second mode, A battery impedance measuring device characterized by determining the internal impedance based on the above. Configuration 6: The battery impedance measuring device described in configuration 5, One end of the first resonant circuit and one end of the second resonant circuit are in contact with the positive or negative electrode of the battery, respectively. The control unit, The damped oscillation waveform of the first resonant circuit when operating in the first mode, The damped oscillation waveform of the first resonant circuit when operating in the second mode, The damped oscillation waveform of the second resonant circuit when operating in the second mode, A battery impedance measuring device characterized by determining, in addition to the internal impedance, the contact resistance between one end of the first resonant circuit and the battery, and the contact resistance between one end of the second resonant circuit and the battery, based on the above. Composition 7: A battery impedance measuring device according to configuration 5 or configuration 6, The control unit, A battery impedance measuring device characterized by determining the internal impedance based on the damped oscillation waveform of the first resonant circuit when operating in the first mode, and a composite time waveform when operating in the second mode, which is a composite time waveform obtained by combining the damped oscillation waveform of the first resonant circuit and the damped oscillation waveform of the second resonant circuit. Composition 8: A battery impedance measuring device according to any one of configurations 5 to 7, The control unit, A battery impedance measuring device characterized by determining the internal impedance based on the degree to which the damped oscillation waveform of the first resonant circuit is attenuated when it operates in the first mode, and the degree to which the composite time waveform is attenuated. Composition 9: A battery impedance measuring device according to any one of configurations 5 to 8, The first mode described above is, This is an operating mode in which, when the first switch corresponding to the first resonant circuit and the second switch corresponding to the second resonant circuit are in the off state, the first switch is turned on from off and the second switch is kept off. The second mode is, A battery impedance measuring device characterized by an operating mode in which, when the first switch is off and the second switch is on, the first switch is turned on and the second switch is kept on. Configuration 10 A battery impedance measuring device according to any one of configurations 5 to 8, The first mode described above is, This is an operating mode in which, when the first switch corresponding to the first resonant circuit and the second switch corresponding to the second resonant circuit are in the off state, the first switch is turned on from off and the second switch is kept off. The second mode is, A battery impedance measuring device characterized by an operating mode in which, when the first switch is on and the second switch is off, the first switch is kept on and the second switch is turned from off to on. [Explanation of Symbols]

[0127] 10 Battery, 12 Control Unit, 14, 14S, 16, 16S Buffer Amplifier, 18 Adder Circuit, 20 Subtractor Circuit, 22 Selector Circuit, 24 Peak Hold Circuit, 100, 102, 103, 104, 106, 108 Battery Impedance Measurement Device, Rs1 First Resonant Circuit, Rs2 Second Resonant Circuit, SW1 First Switch, SW2 Second Switch, SW3 Third Switch, SW4 Fourth Switch, L res1 First resonant inductor, C res1 First resonant capacitor, R res1 First discharge resistance, L res2 Second resonant inductor, C res2 Second resonant capacitor, R res2 second discharge resistor, C res3 Third resonant capacitor, R res3 Third discharge resistance, C res4 Fourth resonant capacitor, R res4 4th discharge resistance, T 1p First positive terminal, T 2p Second positive terminal, T 1n 1st negative terminal, T 2n 2nd negative terminal, R c1p ,R c1n , R c2p ,R c2n Contact resistance, L pick1 First pickup inductor, Lp ick2 Second pickup inductor, Tp positive phase terminal, Tn negative phase terminal, CS1 first capacitor switch block, CS2 second capacitor switch block, CS3 third capacitor switch block, CS4 fourth capacitor switch block.

Claims

1. Multiple resonant circuits that pass a resonant current through the battery to be measured, A waveform acquisition unit that acquires the damped oscillation waveform of the current flowing through each of the aforementioned resonant circuits, A control unit that determines the internal impedance of the battery based on the damped oscillation waveform obtained for each of the aforementioned resonant circuits, A switch controlled by the control unit and provided corresponding to each of the resonant circuits, the switch provided between the corresponding resonant circuit and the battery, The control unit, A battery impedance measuring device characterized by determining the internal impedance based on multiple damped oscillation waveforms for each resonant circuit, which are obtained for multiple switch operations with different combinations of switch operations.

2. A battery impedance measuring device according to claim 1, One end of each of the aforementioned resonant circuits is individually in contact with the positive or negative electrode of the battery. The control unit, A battery impedance measuring device characterized by determining the contact resistance value between one end of each resonant circuit and the battery, in addition to the internal impedance, based on multiple damped oscillation waveforms for each resonant circuit obtained for multiple switch operations with different combinations of switch operations.

3. A battery impedance measuring device according to claim 1 or claim 2, The control unit, A composite time waveform is obtained by combining the damped oscillation waveforms for each of the aforementioned resonant circuits. A battery impedance measuring device characterized by determining the internal impedance based on the aforementioned synthesized time waveform.

4. A battery impedance measuring device according to claim 1 or claim 2, The control unit, A battery impedance measuring device characterized by determining the internal impedance based on the degree of attenuation of multiple damped vibration waveforms for each resonant circuit, which are obtained for multiple different combinations of switch operations where each switch operates differently.

5. A battery impedance measuring device according to claim 1, The battery is supplied with a plurality of resonant circuits, including a first resonant circuit and a second resonant circuit, which supply a resonant current to the battery. The control unit, The operation of the first switch corresponding to the first resonant circuit and the operation of the second switch corresponding to the second resonant circuit are performed in different first and second modes, respectively. The damped oscillation waveform of the first resonant circuit when operating in the first mode, The damped oscillation waveform of the first resonant circuit when operating in the second mode, The damped oscillation waveform of the second resonant circuit when operating in the second mode, A battery impedance measuring device characterized by determining the internal impedance based on the above.

6. A battery impedance measuring device according to claim 5, One end of the first resonant circuit and one end of the second resonant circuit are in contact with the positive or negative electrode of the battery, respectively. The control unit, The damped oscillation waveform of the first resonant circuit when operating in the first mode, The damped oscillation waveform of the first resonant circuit when operating in the second mode, The damped oscillation waveform of the second resonant circuit when operating in the second mode, A battery impedance measuring device characterized by determining, in addition to the internal impedance, the contact resistance between one end of the first resonant circuit and the battery, and the contact resistance between one end of the second resonant circuit and the battery, based on the above.

7. A battery impedance measuring device according to claim 5 or claim 6, The control unit, A battery impedance measuring device characterized by determining the internal impedance based on the damped oscillation waveform of the first resonant circuit when operating in the first mode, and a composite time waveform when operating in the second mode, which is a composite time waveform obtained by combining the damped oscillation waveform of the first resonant circuit and the damped oscillation waveform of the second resonant circuit.

8. A battery impedance measuring device according to claim 7, The control unit, A battery impedance measuring device characterized by determining the internal impedance based on the degree to which the damped oscillation waveform of the first resonant circuit is attenuated when it operates in the first mode, and the degree to which the composite time waveform is attenuated.

9. A battery impedance measuring device according to claim 5 or claim 6, The first mode is, This is an operating mode in which, when the first switch corresponding to the first resonant circuit and the second switch corresponding to the second resonant circuit are in the off state, the first switch is turned on and the second switch is kept off. The second mode is, A battery impedance measuring device characterized by an operating mode in which, when the first switch is off and the second switch is on, the first switch is turned on and the second switch is kept on.

10. A battery impedance measuring device according to claim 5 or claim 6, The first mode is, This is an operating mode in which, when the first switch corresponding to the first resonant circuit and the second switch corresponding to the second resonant circuit are in the off state, the first switch is turned on and the second switch is kept off. The second mode is, A battery impedance measuring device characterized in that, when the first switch is on and the second switch is off, there is an operating mode that keeps the first switch on and switches the second switch from off to on.

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