JP7315372B2 - Impedance measurement system and impedance measurement method - Google Patents

Description

The present invention relates to an impedance measurement system and an impedance measurement method.

A four-terminal method (see Patent Document 1 below) is known as one of the methods for measuring the impedance of conductor patterns, batteries, elements, etc. (hereinafter referred to as "test samples (DUTs)") present on a circuit board. An impedance measuring device using the four-terminal method is configured using a twisted cable formed by twisting a current measuring line from a pair of output terminals of a measurement signal source and a voltage measuring line from a voltmeter (see FIG. 5). In FIG. 5, the impedance measurement system 200 includes an impedance measurement device 203 connected to a battery cell 220 via current measurement lines (current cables) 213 and 214 and voltage measurement lines (voltage cables) 215 and 216 . The impedance measuring device 203 includes a measurement signal source 205 that generates a measurement signal, a voltmeter 209 as voltage detection means, and an ammeter 207 as current detection means.

Specifically, as shown in FIG. 5, a measurement current Is is passed through the tab terminals 220a and 220b of the battery cell 220 to be measured from the measurement signal source 205 through the twisted cable formed by twisting the current measurement lines 213 and 214. At the same time, the voltage value _V1 of the voltage between the tab terminals 220a and 220b of the battery cell 220 is measured by the voltmeter 209, and the current value of the measurement current Is is measured by the ammeter 207. . The impedance Z of the battery cell 220 is calculated based on the current value of the measured current Is and the voltage value _V1 . According to the impedance measuring apparatus using this four-terminal method, the influence of the wiring resistance of the electrical wiring (lead wire) of the measurement system and the contact resistance with the sample to be measured can be almost eliminated.

As another method for measuring the impedance of a device under test (DUT), a 4-terminal pair method is known (see Patent Document 1 below). An impedance measuring device using the 4-terminal pair method uses coaxial cables as electrical wiring for four current probes, and connects and short-circuits all of the outer conductors (shielded covered wires) of each coaxial cable with lead wires near the base end of each probe.

According to the above-described four-terminal method, the outward and return paths of the measurement current Is are overlapped in the measurement current path, so the influence of the magnetic flux (electromagnetic induction) caused by the measurement current can be reduced.

JP 2011-257340 A

However, in the four-terminal method, an induced voltage is induced in the voltage measurement line by the magnetic flux generated by the measurement current flowing in the current measurement line (see the magnetic flux lines in FIG. 5), and the induced voltage is superimposed on the voltage across the battery measured by the voltmeter, causing an error in the measurement result. Further, as shown in FIG. 5, when the object to be measured is, for example, a laminated battery cell (primary battery, secondary battery, etc.) for EV, the distance between the terminals of the battery cell may be as long as about 800 mm. In the vicinity of the battery cell, a loop is formed in which a leakage magnetic flux is generated in the current path to which the measurement current is applied (the area surrounded by the ellipse in FIG. 5).

In addition, a loop intersecting with the above-described leakage magnetic flux generated in the current path also occurs in the path of the voltage measurement line connecting the voltage detection unit and the battery cell (the area surrounded by the ellipse in FIG. 5). Therefore, there is a problem that the loops in the path of the current measurement line and the path of the voltage measurement line are physically overlapped with each other, so that they are easily affected by electromagnetic induction.

In addition, when there are multiple objects to be measured, each time the object to be measured is changed, the terminals of the current measurement line and the voltage measurement line on the side of the object to be measured must be reconnected to the terminal of the changed object to be measured, leading to a delay in processing time.

Therefore, an object of the present invention is to provide an impedance measurement system capable of suppressing the influence of electromagnetic induction caused by a magnetic flux leakage loop generated in a portion of a current measurement line near a terminal to be measured and a magnetic flux leakage generated in a portion of a voltage measurement line near a terminal to be measured.

One aspect of the impedance measuring system according to the present invention is an impedance measuring apparatus which measures the impedance of each of the electronic components to be measured, which is an electronic component to be measured having at least one pair of terminals and includes a measurement signal generation source that supplies a measurement signal of a predetermined frequency to at least one set of electronic components to be measured, a current detection section that detects a current flowing through the electronic component to be measured that is arranged between a pair of output terminals of the measurement signal generation source and the other, and at least one voltage detection section that measures a voltage generated between both terminals of each of the electronic components to be measured. wherein one and the other of the pair of electronic components to be measured are superimposed in a current path between one and the other of a pair of output terminals of a measurement signal generation source, and a current path is formed between the pair of electronic components to be measured, the measurement signal generation source, and the current detection unit such that the direction of the current flowing in one of the pair of electronic components to be measured and the direction of the current flowing in the other of the pair of electronic components to be measured are opposite to each other.

Another aspect of the impedance measurement system according to the present invention is an electronic component to be measured having at least one pair of terminals, and includes: a measurement signal generation source that supplies a measurement signal of a predetermined frequency to at least one set of electronic components to be measured; a current detection unit that is arranged between a pair of output terminals of the measurement signal generation source and that flows through the electronic component to be measured; An impedance measuring system having a measuring device, characterized in that a pair of electronic components to be measured are disposed in a current path between one and the other of a pair of output terminals of a measurement signal generation source, and one terminal of one electronic component to be measured and the other terminal of the other electronic component to be measured are short-circuited to connect one electronic component to be measured and the other electronic component to be measured in series.

Another aspect of the impedance measurement system according to the present invention is characterized in that, when a plurality of sets of electronic components to be measured are arranged, the number of voltage detection units corresponding to one electronic component to be measured and the other electronic component to be measured in each set of electronic components to be measured is provided, and the voltage between both terminals of each electronic component to be measured in each set is detected by each voltage detection unit.

Another aspect of the impedance measurement system according to the present invention is that when a plurality of sets of electronic components to be measured are composed of a first electronic component to n-th electronic component to be measured (n is an integer equal to or greater than 2), and the first electronic component to n-th electronic component to be measured are arranged adjacent to each other in that order, one of the pair of output terminals of the measurement signal generation source is connected to the terminal of the first electronic component on the side of the measurement signal generation source, and the other of the pair of output terminals of the measurement signal generation source serves as a current detection unit. The electronic component is connected to a terminal on the measurement signal generation side of the n-th electronic component to be measured via the first electronic component to the n-th electronic component to be measured.

Another aspect of the impedance measurement system according to the present invention is characterized in that, when a plurality of sets of electronic components to be measured are arranged, the voltage detection section is connected to the first to n-th electronic components to be measured for each measurement of the first to n-th electronic components to be measured.

Another aspect of the impedance measurement system according to the present invention includes a signal selection section having a plurality of switches when a plurality of sets of electronic components to be measured are arranged, the plurality of switches comprising at least a first switch group connected to the measurement signal generation source, a second switch group connected to the current detection section, and a third switch group connected to the voltage detection section. a second input terminal connected to a second current measuring line end on the other end of the current measuring line; a first output terminal connected to a third current measuring line end on the other end of the current measuring line connected to the electronic component to be measured; and a second output terminal connected to a fourth current measuring line end on the other end of the current measuring line. a third input terminal connected to the end of the first current measurement line on the end side; a fourth input terminal connected to the end of the second current measurement line on the other end of the current measurement line; a third output terminal connected to the end of the third current measurement line on the other end of the current measurement line connected to the electronic component to be measured; and a fourth output terminal connected to the end of the fourth current measurement line on the other end of the current measurement line. a fifth input terminal connected to the end of the first voltage measurement line on the other end of the voltage measurement line connected to the detector; a sixth input terminal connected to the end of the second voltage measurement line on the other end of the voltage measurement line; a fifth output terminal connected to the end of the third voltage measurement line on the other end of the voltage measurement line connected to the electronic component to be measured; , the signal selection unit switches the first to sixth output terminals of the first to third switch groups according to the change of the measurement object for each of the plurality of sets of the electronic components to be measured, and by switching, the voltage applied to both ends of one of the electronic components to be measured and the other electronic component to be measured in each set is detected for each set of electronic components to be measured.

In one aspect of the impedance measuring method of the present invention, an electronic component to be measured having at least a pair of terminals is arranged between a pair of output terminals of a measurement signal generation source that supplies a measurement signal of a predetermined frequency to at least one set of electronic components to be measured. An impedance measuring method for measuring the impedance of each component, wherein one and the other of the pair of electronic components to be measured are superimposed and arranged in a current path between one and the other of a pair of output terminals of a measurement signal generation source, and a current path is formed between the set of electronic components to be measured, the measurement signal generation source, and the current detection section so that the direction of the current flowing in one of the pair of electronic components to be measured and the direction of the current flowing in the other of the set of electronic components to be measured are opposite to each other.

Another aspect of the impedance measuring method of the present invention is an electronic component to be measured which has at least a pair of terminals and is arranged between a pair of output terminals of a measurement signal generating source which supplies a measurement signal of a predetermined frequency to at least one set of electronic components to be measured. An impedance measuring method for measuring the impedance of each electronic component, characterized in that one of a pair of electronic components to be measured and the other are arranged in a current path between one and the other of a pair of output terminals of a measurement signal generation source, and a current path is formed between the set of electronic components to be measured, the measurement signal generation source, and the current detection section so that the direction of the current flowing in one of the pair of electronic components to be measured and the direction of the current flowing in the other of the set of electronic components to be measured are opposite to each other.

According to another aspect of the impedance measuring method of the present invention, the electronic component to be measured has at least one pair of terminals, and is arranged between a pair of output terminals of a measurement signal generating source that supplies a measurement signal of a predetermined frequency to the at least one set of electronic component to be measured. An impedance measuring method for measuring the impedance of each component, wherein a set of electronic components to be measured is arranged in a current path between one and the other of a pair of output terminals of a measurement signal generation source, and one terminal of one electronic component to be measured and the other terminal of the other electronic component to be measured are short-circuited to connect one electronic component to be measured and the other electronic component to be measured in series.

It is possible to provide an impedance measurement system and a measurement method that can suppress the influence of electromagnetic induction caused by a magnetic flux leakage loop generated in a part of a current measurement line near a terminal to be measured and a magnetic flux leakage generated in a part of a voltage measurement line near a terminal to be measured and shorten the measurement processing time.

1 is a diagram showing the configuration of an impedance measurement system according to a first embodiment of the present invention, and showing a first connection configuration mode; FIG. FIG. 10 is a diagram showing the configuration of an impedance measurement system according to a second embodiment of the present invention, and showing a second connection configuration mode; It is the figure which showed the structure of the impedance measurement system based on the modification of the 2nd Embodiment of this invention. It is a diagram showing the configuration of an impedance measurement system according to a third embodiment of the present invention. 1 is a diagram showing the configuration of a conventional impedance measurement system; FIG.

<First embodiment>
A first embodiment of an impedance measurement system according to the present invention will be described below with reference to FIG. The electronic components to be measured by the impedance measurement system (hereinafter referred to as “measurement targets”) are battery cells and elements that make up an electric circuit, and the impedance is measured as an important electrical parameter for evaluating the characteristics of battery cells and elements. In this embodiment, a battery cell will be described as an example of a measurement object. The present invention is characterized by the mode of connection between the impedance measuring device and the battery cells that constitute the impedance measuring system.

[Configuration of impedance measurement system]
The impedance measurement system 1 includes an impedance measurement device 3 connected to battery cells 31 and 33 via shield wires 21 and 27 . The impedance measuring device 3 includes a measurement signal source 11 that generates a measurement signal, an ammeter 13 as a current detector, and a first voltmeter 15 and a second voltmeter 17 as voltage detectors. Note that the measurement signal source 11 corresponds to the measurement signal generation source of claim 1 .

[Connection between measuring device and battery cell]
A connection mode between the impedance measuring device 3 and the battery cells 31 and 33 to be measured will be described below. When measuring the impedance of the battery cells 31 and 33 with the impedance measuring device 3, the measurement signal source 11, the first voltmeter 15, the second voltmeter 17 and the ammeter 13 and the battery cells 31 and 33 need to be connected via probes P1 to P8. Although each of these probes has the same structure, for convenience of explanation, the probe on the current system side will be referred to as a current probe and the probe on the voltage system side will be referred to as a voltage probe in this specification.
As probes, four current probes P1, P2, P3, and P4 included in a measurement current loop that is a path of current flowing from the measurement signal source 11 to the battery cells 31 and 33, two voltage probes P5 and P6 included in the voltage detection loop of the battery cell 31, and two voltage probes P7 and P8 included in the voltage detection loop of the battery cell 33 are used.

Here, shielded wires (coaxial cables) 21 and 27 are used as the electrical wiring for the current probes P1, P2, P3, and P4, a twisted cable 23 formed by twisting the voltage measurement lines 23a and 23b is used as the electrical wiring for the voltage probes P5 and P6, and a twisted cable 25 formed by twisting the voltage measurement lines 25a and 25b is used as the electrical wiring for the voltage probes P7 and P8.

The tab terminal 31a of the battery cell 31 is connected to one of a pair of output terminals of the measurement signal source 11 via the probe P1 and the core wire 21a of the shielded wire 21, and the other tab terminal 31b is connected to the input part of the ammeter 13 via the probe P3 and the core wire 27a of the shielded wire 27. The tab terminal 33a of the battery cell 33 is connected to the other of the pair of output terminals of the measurement signal source 11 via the probe P2 and the shield conductor 21b (return line) of the shield wire 21, and the other tab terminal 33b is connected to the output of the ammeter 13 via the probe P4 and the shield conductor 27b (return wire) of the shield wire 27.

In this manner, the battery cells 31 and 33 are arranged such that the direction of the measurement current flowing through the battery cell 31 and the direction of the measurement current flowing through the battery cell 33 are opposite to each other. In the example of FIG. 1, the direction of the measurement current flowing through the battery cell 31 is from the measurement signal source 11 to the ammeter (leftward arrow), and the direction of the measurement current flowing through the battery cell 33 is from the ammeter 13 to the measurement signal source 11 (rightward arrow), which is opposite to each other.

The tab terminal 31a of the battery cell 31 is connected to the voltage measurement line 23a of the twisted cable 23 via the probe P5, and the other tab terminal 31b is connected to the voltage measurement line 23b of the twisted cable 23 via the probe P6.
The first voltmeter 15 is disposed between the end of the voltage measurement line 23a and the end of the voltage measurement line 23b on one end side of the twisted cable 23, measures the voltage _V1 generated between the end of the voltage measurement line 23a and the end of the voltage measurement line 23b due to the measurement current Is flowing in the measurement current loop, and outputs the measured voltage _V1 to an arithmetic processing unit (included in the measurement device 3) not shown. The second voltmeter 17 is disposed between the end of the voltage measurement line 25a and the end of the voltage measurement line 25b on one end side of the twisted cable 25, measures the voltage _V2 generated between the end of the voltage measurement line 25a and the end of the voltage measurement line 25b due to the measurement current Is flowing in the measurement current loop, and outputs the measured voltage _V2 to the arithmetic processing unit described above.

[Measuring method]
Regarding the impedance measurement of the battery cell 31, the impedance _Z31 of the battery cell 31 is calculated based on the current value of the measured current Is (the current flowing through the battery cell 31) measured by the ammeter 13 in the arithmetic processing unit and the voltage value of the voltage _V1 generated across the battery cell 31.

Regarding the impedance measurement of the battery cell 33, the impedance _Z33 of the battery cell 33 is calculated based on the current value of the measured current Is (the current flowing through the battery cell 33) measured by the ammeter 13 in the arithmetic processing unit and the voltage value of the voltage _V2 generated across the battery cell 33.

The voltages V ₁ and V ₂ between the terminals of the battery cells 31 and 33 are measured at the same time, and the first voltmeter 15 and the second voltmeter 17 are detected in accordance with the polarity of the measured current Is because the polarity (positive, negative) of the measured current Is is reversed. In this example, the case where two voltmeters are used is explained, but when a scanner (see FIG. 4), which will be described later, is used, even if there is only one voltmeter, each time the object to be measured is changed, the switches constituting the scanner can be used to switch the voltmeter, and the impedance can be measured sequentially.

[effect]
According to the impedance measurement system according to the first embodiment described above, a set of battery cells is used so that the direction of the current flowing through each battery cell is made different, so the generation of magnetic flux in the battery cells can be suppressed. In addition, since the loop length of the measurement current loop that flows from the measurement signal source 11 that applies the measurement current Is through the battery cell can be minimized compared to the loop length of the conventional measurement current loop (see FIG. 5), the loop through which the magnetic flux generated by the measurement current leaks can be minimized.

Since the position of the voltage detection loop and the position of the measurement current loop starting from the voltmeter can be separated, the influence of electromagnetic induction caused by overlapping of the measurement current loop and the voltage detection loop can be reduced. Also, if the voltmeter has two channels, two battery cells can be measured simultaneously, so the measurement time can be shortened. It should be noted that the influence of electromagnetic induction can be similarly reduced in cylindrical cells other than laminated battery cells, prismatic cells, and measurement objects other than batteries.

<Second Embodiment>
A second embodiment of the impedance measurement system according to the present invention will be described below with reference to FIG. In the second embodiment, as in the first embodiment described above, a set of battery cells, which are arranged so as to overlap each other at a short distance, will be described as an example of an object to be measured. However, the present invention can also be applied to other elements, such as elements that form an electric circuit.

[Configuration of impedance measurement system]
The impedance measurement system 40 includes an impedance measurement device 43 connected to battery cells 61 and 63 via current measurement lines (current cables) 51 and 52 and voltage measurement lines (voltage cables) 53 , 54 , 55 and 56 . The impedance measuring device 43 includes a measurement signal source 44 that generates measurement signals, a first voltmeter 46 and a second voltmeter 48 as voltage detection means, and an ammeter 45 as current detection means. Note that the measurement signal source 44 corresponds to the measurement signal generation source of claim 1 .

[Connection between measuring device and battery cell]
A connection mode between the impedance measuring device 43 and the battery cells 61 and 63 to be measured will be described below. When measuring the impedances Z ₆₁ and Z 63 of the battery cells 61 and ₆₃ to be measured by the impedance measuring device 43, the measurement signal source 44, the ammeter 45, the first voltmeter 46, the second voltmeter 48 and the battery cells 61 and 63 are connected via current measurement lines 51 and 52 and voltage measurement lines 53, 54, 55 and 56. Here, two current probes P1 and P2 included in the measurement current loop that is the path of current flowing from the measurement signal source 44 to the ammeter 45 through the battery cells 61 and 63, two voltage probes P3 and P4 that are included in the voltage detection loop that is the path for voltage detection of the battery cell 61, and two voltage probes P5 and P6 that are included in the voltage detection loop that is the path for voltage detection of the battery cell 63 are used. A twisted cable formed by twisting the current measurement lines 51 and 52 is used as the electrical wiring of the current probes P1 and P2, a twisted cable formed by twisting the voltage measurement lines 53 and 54 is used as the electrical wiring of the voltage probes P3 and P4, and a twisted cable formed by twisting the voltage measurement lines 55 and 56 is used as the electrical wiring of the voltage probes P5 and P6.

One of the pair of output terminals (not shown) of the measurement signal source 44 is connected to the tab terminal 61a of the battery cell 61 via the current measurement line 51 and the current probe P1, and the other of the pair of output terminals of the measurement signal source 44 is connected to the tab terminal 63a of the battery cell 63 via the ammeter 45, the current measurement line 52 and the current probe P2.

In this manner, the battery cells 61 and 63 are arranged such that the direction of the measurement current flowing through the battery cell 61 and the direction of the measurement current flowing through the battery cell 63 are opposite to each other. In the example of FIG. 2, the direction of the measurement current flowing through the battery cell 61 is in the direction away from one output terminal of the measurement signal source 44 (the rightward arrow in FIG. 2), and the direction of the measurement current flowing in the battery cell 63 is the direction toward the measurement signal source 44 (the leftward arrow in FIG. 2), which is opposite to each other.

A tab terminal 61 b of the battery cell 61 is connected to a tab terminal 63 b of the battery cell 63 via a short-circuit wire 58 . The first voltmeter 46 is arranged between the end of the voltage measurement line 53 and the end of the voltage measurement line 54, measures the voltage _V1 generated between the end of the voltage measurement line 53 and the end of the voltage measurement line 54 due to the measurement current Is flowing in the measurement current loop, and outputs the measured voltage _V1 to an arithmetic processing unit (not shown).

The second voltmeter 48 is arranged between the end of the voltage measurement line 55 and the end of the voltage measurement line 56, measures the voltage _V2 generated between the end of the voltage measurement line 55 and the end of the voltage measurement line 56 due to the measurement current Is flowing in the measurement current loop, and outputs the measured voltage _V2 to an arithmetic processing section (included in the measurement section) (not shown).

[Measuring method]
Regarding the impedance measurement of the battery cell 61, the impedance Z ₆₁ of the battery cell 61 is calculated based on the current value of the measured current Is (the current flowing through the battery cell 61) measured by the ammeter 45 in the arithmetic processing unit and the voltage value of the voltage _V1 generated across the battery cell 61.

Regarding the impedance measurement of the battery cell 63, the impedance Z ₆₃ of the battery cell 63 is calculated based on the current value of the measured current Is (the current flowing through the battery cell 63) measured by the ammeter 45 in the arithmetic processing unit and the voltage value of the voltage _V2 generated across the battery cell 63.

Note that the voltages V ₁ and V ₂ between the terminals of the battery cells 61 and 63 are measured at the same time, and the first voltmeter 46 and the second voltmeter 48 are detected in accordance with the polarity of the measured current Is because the polarity (positive, negative) of the measured current Is is reversed. In this example, the case where two voltmeters are used has been described, but when a scanner, which will be described later, is used, even if there is only one voltmeter, the impedance can be measured sequentially by switching the switch that constitutes the scanner each time the object to be measured is changed.

[effect]
According to the impedance measurement system according to the second embodiment described above, since a set of battery cells is used and the directions of the currents flowing through the battery cells 61 and 63 are made different, the generation of magnetic flux in the battery cells 61 and 63 can be suppressed. In addition, since the loop length of the measurement current loop that flows from the measurement signal source 44 that applies the measurement current Is through the battery cells 61 and 63 can be minimized compared to the loop length of the conventional measurement current loop (see FIG. 5), the loop through which the magnetic flux generated by the measurement current leaks can be minimized.

Since the position of the voltage detection loop and the position of the measurement current loop starting from the voltmeter can be separated, the influence of electromagnetic induction caused by overlapping of the measurement current loop and the voltage detection loop can be reduced. In addition, since two voltmeters are used and two battery cells can be measured simultaneously, the measurement time can be shortened. It should be noted that the influence of electromagnetic induction can be similarly reduced in cylindrical cells other than laminated battery cells, prismatic cells, and measurement objects other than batteries.

<Modification>
A modification of the impedance measurement system according to the above-described second embodiment will be described below with reference to FIG. In the above-described second embodiment, the object to be measured is a set of battery cells (the number of cells is two), whereas the object to be measured in this modification is two sets of battery cells (the number of cells is four), which are placed one on top of the other at a short distance. In this modified example, a battery cell is described as an example of an object to be measured. Moreover, since it is the same as the above-described second embodiment except for the connection mode between the impedance measuring device and the battery cells and the number of battery cells, only different parts will be described.

[Connection between measuring device and battery cell]
A connection mode between the impedance measurement system 70 and the battery cells 91, 93, 95, and 97 to be measured will be described below. In order to measure the impedances _{Z91, Z93, Z95, and Z97 of the battery cells 91} , ₉₃ , ₉₅ , and ₉₇ to be measured in the impedance measurement system 70, the impedance measurement device 73 including the measurement signal source 81, the ammeter 82, and the voltmeter 83 is connected to the battery cells 91, 93, 95, and 97 via current measurement lines 84, 85 and voltage measurement lines 86, 87.
One of the pair of output terminals (not shown) of the measurement signal source 81 is connected to the tab terminal 91b of the battery cell 91 via the current measurement line 84, and the other of the pair of output terminals of the measurement signal source 81 is connected to the tab terminal 97b of the battery cell 97 via the ammeter 82 and the current measurement line 85. A tab terminal 91a of the battery cell 91 and a tab terminal 93b of the battery cell 93 are connected via a short-circuit line 88, a tab terminal 93a of the battery cell 93 and a tab terminal 95b of the battery cell 95 are connected via a short-circuit line 89, and a tab terminal 95a of the battery cell 95 and a tab terminal 97a of the battery cell 97 are connected via a short-circuit line 90.
In this manner, the battery cells 91, 93, 95 and 97 are connected to each other such that the direction of the measured current flowing through each of the battery cells 91, 93, 95 and 97 is opposite to the direction of the measured current flowing through the adjacent battery cells.

[Measuring method]
The voltage measurement between the tab terminals of the battery cells 91, 93, 95 and 97 is performed by switching the voltage probes P3 and P4 located at the respective ends of the voltage measurement lines 86 and 87 to the battery cells 91, 93, 95 and 97 in order according to the polarity of the measurement current Is. Specifically, first, the voltage probes P3 and P4 are connected to the pair of tab terminals 91b and 91a of the battery cell 91, respectively, and the voltage _V1 between the tab terminals 91b and 91a of the battery cell 91 is measured according to the polarity (e.g., positive polarity) of the measurement current Is. After that, the voltage probes P3 and P4 are connected to the pair of tab terminals 93a and 93b of the battery cell 93, respectively, and the voltage _V2 between the tab terminals 93a and 93b of the battery cell 93 is measured according to the polarity (for example, positive polarity) of the current Is to be measured. After that, the voltage probes P3 and P4 are connected to the pair of tab terminals 95b and 95a of the battery cell 95, respectively, and the voltage _V3 between the tab terminals 95a and 95b of the battery cell 95 is measured according to the polarity (for example, positive polarity) of the current Is to be measured. After that, the voltage probes P3 and P4 are connected to the pair of tab terminals 97b and 97a of the battery cell 97, respectively, and the voltage _V4 between the tab terminals 97a and 97b of the battery cell 97 is measured according to the polarity (for example, positive polarity) of the current Is to be measured.

[effect]
According to the impedance measurement system according to the above modification, two sets of battery cells are used so that the direction of the measurement current flowing in each of the battery cells 91, 93, 95, and 97 is opposite to the direction of the measurement current flowing in the adjacent battery cell. In addition, since the loop length of the measurement current loop that flows from the measurement signal source 81 that applies the measurement current Is through the battery cells 91, 93, 95, and 97 can be minimized compared to the loop length of the conventional measurement current loop (see FIG. 5), the loop through which the magnetic flux generated by the measurement current leaks can be minimized.

Since the position of the voltage detection loop and the position of the measurement current loop starting from the voltmeter can be separated, the influence of electromagnetic induction caused by overlapping of the measurement current loop and the voltage detection loop can be reduced. It should be noted that the influence of electromagnetic induction can be similarly reduced in cylindrical cells other than laminated battery cells, prismatic cells, and measurement objects other than batteries.

<Third Embodiment>
A third embodiment of the impedance measurement system according to the present invention will be described below with reference to FIG. The third embodiment is the same as the impedance measuring system according to the above-described first embodiment, except that the scanner 5 is arranged between the impedance measuring device 3 and the battery cells 31, 33, 35, and 37, and that two pairs of battery cells are arranged. Therefore, mainly different points will be described in detail. Although the battery cells 31, 33 of one set and the battery cells 35, 37 of the other set are arranged close to each other, they are shown separated by a predetermined distance in FIG. Note that the scanner 5 corresponds to the signal selection unit of claim 5 .

[Configuration of impedance measurement system]
The impedance measurement system 100 includes an impedance measurement device 3 , a scanner 5 , a first set of battery cells 31 and 33 and a second set of battery cells 35 and 37 . The impedance measuring device 3 includes a measurement signal source 11 , a first voltmeter 15 and a second voltmeter 17 , and an ammeter 13 . The shielded wires 21, 27 and the twisted cables 23, 25 are the same as those in the first embodiment, but depending on the selection of the switches 101 to 108 of the scanner 5, the shielded wire 21 is connected to either of the shielded wires 121, 221, the twisted cable 23 is connected to either of the twisted cables 123, 223, the twisted cable 25 is connected to either of the twisted cables 125, 225, and the shielded wire 27 is connected to the shielded wire. 127, 227. The switches 101 and 102 correspond to the first switch group of claim 5, the switches 107 and 108 correspond to the second switch group of claim 5, and the switches 103 and 104 and switches 105 and 106 correspond to the third switch group of claim 5. The core wire 121a and the shield conductor 121b (return wire), the core wire 127a and the shield conductor 127b (return wire), the core wire 221a and the shield conductor 221b (return wire), and the core wire 227a and the shield conductor 227b (return wire), which constitute the shield wires 121, 127, 221, and 227 as electrical wiring of the current probes P1, P2, P3, and P4, are connected to the scanner 5. They are arranged in close proximity to each other for internal electromagnetic induction suppression. This makes the current loop smaller. Also, the voltage probes P5 and P7 and the voltage probes P6 and P8 can be run in parallel to reduce the voltage measurement loop. Further, inside the scanner 5, for example, a current measurement line connecting the terminal b1 of the switch 101 and the core wire 121a and a current measurement line connecting the terminal b2 of the switch 102 and the shield conductor 121b are run in close parallel, a current measurement line connecting the terminal c1 of the switch 101 and the core wire 221a and a current measurement line connecting the terminal c2 of the switch 102 and the shield conductor 221b are run in close parallel, and the terminal b7 of the switch 107 and the core wire are run in parallel. 127a and the current measurement line connecting the terminal b8 of the switch 108 and the shield conductor 127b are run in close parallel with each other, and the current measurement line connecting the terminal c7 of the switch 107 and the core wire 227a and the current measurement line connecting the terminal c8 of the switch 108 and the shield conductor 227b are run close together in parallel. Further, the voltage measurement lines connecting the switches 103 to 106 and the twisted cables 123, 125, 223, 225 are also run close together in the same manner as described above, so that electromagnetic induction can be suppressed inside the scanner 5 as well.

[Connection between measuring device and battery cell]
As shown in FIG. 4, the scanner 5 has switches 101 to 108 as signal selection units, and the first connection mode and the second connection mode are generated depending on the mode of selection (switching) of the switches 101 to 108 . Therefore, below, it divides into a 1st connection mode and a 2nd connection mode, and demonstrates.

In the first connection mode, the switch 101 selects the terminal b1 connected to the core wire 121a of the shielded wire 121, and the switch 102 selects the terminal b2 connected to the shield conductor 121b of the shielded wire 121. FIG. The switch 103 selects the terminal b3 connected to the voltage measurement line 123a of the twisted cable 123, and the switch 104 selects the terminal b4 connected to the voltage measurement line 123b of the twisted cable 123. FIG. The switch 105 selects the terminal b5 connected to the voltage measurement line 125a of the twisted cable 125, and the switch 106 selects the terminal b6 connected to the voltage measurement line 125b of the twisted cable 125. FIG. The terminal b7 connected to the core wire 127a of the shielded wire 127 is selected by the switch 107, and the terminal b8 connected to the shield conductor 127b of the shielded wire 127 is selected by the switch .

With this first connection mode, the impedance _Z31 of the battery cell 31 is calculated based on the current value of the measured current Is (the current flowing through the battery cell 31) measured by the ammeter 13 in the arithmetic processing unit and the voltage value of the voltage _V1 generated across the battery cell 31 measured by the voltmeter 15. Furthermore, the impedance Z33 of the battery cell 33 is calculated in the arithmetic processing unit based on the current value of the measured current Is (the current flowing through the battery cell 33) measured by the ammeter 13 and the voltage value of the voltage _V2 generated across the battery cell ₃₃ measured by the voltmeter 17. After that, in a second connection mode described later, a switching operation is performed by an operation unit (not shown) to calculate the impedances Z ₃₅ and Z ₃₇ of the battery cells 35 and 37 .

Regarding the correspondence between the terminals a1 to a4, a7, a8, b1 to b4, b7, and b8 and the terms in claim 5, the terminal a1 corresponds to the "first input terminal," the terminal a2 to the "second input terminal," the terminal a3 to the "fifth input terminal," the terminal a4 to the "sixth input terminal," the terminal a7 to the "third input terminal," and the terminal a. Terminal b1 corresponds to "first output terminal", terminal b2 corresponds to "second output terminal", terminal b3 corresponds to "fifth output terminal", terminal b4 corresponds to "sixth output terminal", terminal b7 corresponds to "third output terminal", and terminal b8 corresponds to "fourth output terminal".

In the second connection mode, the terminal c1 connected to the core wire 221a of the shielded wire 221 is selected by the switch 101, and the terminal c2 connected to the shield conductor 221b of the shielded wire 221 is selected by the switch . The switch 103 selects the terminal c3 connected to the voltage measurement line 223a of the twisted cable 223, and the switch 104 selects the terminal c4 connected to the voltage measurement line 223b of the twisted cable 223. FIG. The switch 105 selects the terminal c5 connected to the voltage measurement line 225a of the twisted cable 225, and the switch 106 selects the terminal c6 connected to the voltage measurement line 225b of the twisted cable 225. FIG. The terminal c7 connected to the core wire 227a of the shielded wire 227 is selected by the switch 107, and the terminal c8 connected to the shield conductor 227b of the shielded wire 227 is selected by the switch . The functions of the probes P11 to P18 are the same as the functions of the probes P1 to P8 in the first connection mode described above.

With this second connection mode, the impedance Z ₃₅ of the battery cell 35 is calculated based on the current value of the measured current Is (the current flowing through the battery cell 35) measured by the ammeter 13 in the arithmetic processing unit and the voltage value of the voltage _V1 generated across the battery cell 35 measured by the voltmeter 15. Furthermore, the impedance _Z37 of the battery cell 37 is calculated in the arithmetic processing unit based on the current value of the measured current Is (the current flowing through the battery cell 33) measured by the ammeter 13 and the voltage value of the voltage _V2 generated across the battery cell 37 measured by the voltmeter 17.

Although the scanner 5 described above has an eight-channel (eight-input) configuration, it goes without saying that if the number of channels is further increased, the number of sets of battery cells to be measured can be increased. Also, the voltage measurement wires connected to the voltmeters 15 and 17 may be shielded wires instead of twisted cables.

[effect]
As described above, according to the third embodiment, in addition to the effects obtained by the impedance measurement system according to the first embodiment, the number of sets of battery cells to be measured can be increased, and more efficient impedance measurement can be performed.

1, 40, 70, 100 impedance measurement system 3, 43, 73 impedance measurement device 5 scanner 11, 44, 81 measurement signal source 13, 45, 82 ammeter 15, 17, 46, 48, 83 voltmeter 21, 35, 27, 121, 127, 221, 227 shielded wire 21a, 27a, 121a, 127a, 221a, 227a Core wire 21b, 27b, 121b, 127b, 221b, 227b Shield conductor 23, 25, 123, 125, 223, 225 Twisted cable 23a, 25a, 123a, 125a, 223a, 225a, 23b, 25b, 123b, 125b, 223b, 2 25b Voltage measurement line 31, 33, 35, 37, 61, 63, 91, 93, 95, 97 Battery cell 31a, 31b, 33a, 33b, 35a, 35b, 37a, 37b, 61a, 61b, 63a, 63b, 91a, 91b, 93a, 93b, 95a, 95b, 97a, 97b Tab terminal 51, 52, 84, 85 current measurement lines 53, 54, 55, 56, 86, 87 voltage measurement lines 58, 88, 89, 90 short-circuit lines 101, 102, 103, 104, 105, 106, 107, 108 switches

Claims (5)

a measurement signal generation source that supplies a measurement signal of a predetermined frequency to the electronic component to be measured;
a current detection unit that detects a current flowing through the electronic component to be measured;
a voltage detection unit that measures a voltage generated between terminals of the electronic component to be measured;
An impedance measurement system having an impedance measurement device that measures the impedance of the electronic component to be measured,
The electronic component to be measured has at least one pair of terminals,
The measurement signal source has at least one pair of output terminals,
The electronic component to be measured is a set of two electronic components to be measured that are placed one on top of the other, and in the set of electronic components to be measured, one terminal of one electronic component to be measured and one terminal of the other electronic component to be measured are short-circuited and connected in series, and a current path is formed such that the direction of the current flowing through one electronic component is opposite to the direction of the current flowing through the other electronic component.
A probe connected to one output terminal of the measurement signal generation source is connected to a terminal of one of the set of electronic components to be measured that is not connected to the other electronic component to be measured,
A probe connected to the other output terminal of the measurement signal generation source is connected to a terminal of the other electronic component to be measured of the set of electronic components to be measured that is not connected to a terminal of the one electronic component to be measured,
A probe connected to the voltage detection unit is connected to a pair of terminals of each of the electronic components to be measured,
An impedance measurement system characterized by: When a plurality of sets of the set of electronic components to be measured are arranged, the voltage detection units are arranged in a number corresponding to one electronic component to be measured and the other electronic component to be measured among the electronic components to be measured in each set, and the voltage between both terminals of each electronic component to be measured in each set is detected by each voltage detection unit.
The impedance measurement system according to claim 1, characterized in that: a measurement signal generation source that supplies a measurement signal of a predetermined frequency to the electronic component to be measured;
a current detection unit that detects a current flowing through the electronic component to be measured;
a voltage detection unit that measures a voltage generated between terminals of the electronic component to be measured;
An impedance measurement system having an impedance measurement device that measures the impedance of the electronic component to be measured,
The electronic component to be measured has at least one pair of terminals,
The measurement signal source has at least one pair of output terminals,
The electronic component to be measured is a set of two electronic components to be measured that are placed one on top of the other, and in the set of electronic components to be measured, one terminal of one electronic component to be measured and one terminal of the other electronic component to be measured are short-circuited and connected in series, and a current path is formed such that the direction of the current flowing through one electronic component is opposite to the direction of the current flowing through the other electronic component.
When the electronic component under test comprises a first electronic component under test to n-th (n is an even number equal to or greater than 2) electronic components under test, and the first electronic component under test through the n-th electronic component under test are arranged adjacent to each other in that order, a probe connected to one of a pair of output terminals of the measurement signal generation source is connected to a terminal of the first electronic component under test on the side of the measurement signal generation source,
a probe connected to the other of a pair of output terminals of the measurement signal generation source is connected to a terminal on the measurement signal generation source side of the nth electronic component to be measured;
one terminal on the self side and the other terminal on the other side of adjacent electronic components to be measured are short-circuited so that the first electronic component to the n-th electronic component to be measured are connected in series;
A probe connected to the voltage detection unit is connected to a pair of terminals of each of the electronic components to be measured,
An impedance measurement system characterized by: When a plurality of sets of the set of electronic components to be measured are arranged,
A signal selection unit having a plurality of switches,
The plurality of switches comprise at least a first switch group connected to the measurement signal generation source, a second switch group connected to the current detection section, and a third switch group connected to the voltage detection section,
The first switch group is
a first input terminal connected to the output side of the measurement signal source;
a first output terminal connected to and disconnected from the first input terminal and connected to one set of the plurality of sets of electronic components to be measured;
a second output terminal connected to and disconnected from the first input terminal and connected to another set of electronic components to be measured among the plurality of sets of electronic components to be measured;
a second input terminal connected to the input side of the measurement signal source;
a third output terminal connected to and disconnected from the second input terminal and connected to one set of the plurality of sets of electronic components to be measured;
a fourth output terminal connected to and disconnected from the second input terminal and connected to another set of electronic components to be measured among the plurality of sets of electronic components to be measured;
consists of
The second switch group is
a third input terminal connected to the current detection unit;
a fifth output terminal connected to and disconnected from the third input terminal and connected to one set of the plurality of sets of electronic components to be measured;
a sixth output terminal connected to and disconnected from the third input terminal and connected to another set of electronic components to be measured among the plurality of sets of electronic components to be measured;
a fourth input terminal connected to the current detection unit;
a seventh output terminal connected to and disconnected from the fourth input terminal and connected to one set of the plurality of sets of electronic components to be measured;
an eighth output terminal connected to and disconnected from the fourth input terminal and connected to another set of electronic components to be measured among the plurality of sets of electronic components to be measured;
consists of
The third switch group is
a fifth input terminal connected to the voltage detection unit;
a ninth output terminal connected to and disconnected from the fifth input terminal and connected to one set of the plurality of sets of electronic components to be measured;
a tenth output terminal connected to and disconnected from the fifth input terminal and connected to another set of electronic components to be measured among the plurality of sets of electronic components to be measured;
a sixth input terminal connected to the voltage detection unit;
an eleventh output terminal connected to and disconnected from the sixth input terminal and connected to one set of the plurality of sets of electronic components to be measured;
a twelfth output terminal connected to and disconnected from the sixth input terminal and connected to another set of electronic components to be measured among the plurality of sets of electronic components to be measured;
consists of
The signal selection unit connects the first output terminal and the second output terminal, the third output terminal and the fourth output terminal, the fifth output terminal and the sixth output terminal, the seventh output terminal and the eighth output terminal, the ninth output terminal and the tenth output terminal, the eleventh output terminal and the first output terminal in the first switch group to the third switch group according to a change in the measurement target for each of the plurality of sets of electronic components to be measured. 2 output terminals,
By the switching, a voltage applied to both ends of one of the sets of electronic components to be measured and the other of the electronic components to be measured is detected for each of the sets of electronic components to be measured.
3. The impedance measurement system according to claim 1 or 2, characterized in that: a measurement signal source supplying a measurement signal of a predetermined frequency to the electronic component to be measured;
A current detection unit detects a current flowing through the electronic component to be measured,
A voltage detection unit measures a voltage generated between terminals of the electronic component to be measured,
An impedance measurement method for measuring the impedance of the electronic component to be measured based on the current value of the detected current and the voltage value of the measured voltage,
The electronic component to be measured has at least one pair of terminals,
The electronic component to be measured is a set of two electronic components to be measured that are placed one on top of the other, and the pair of electronic components to be measured is connected in series by short-circuiting one terminal of the electronic component to be measured and one terminal of the other electronic component to be measured, and a current path is formed such that the direction of the current flowing through one electronic component is opposite to the direction of the current flowing through the other electronic component.
connecting a probe connected to the output of the measurement signal generation source to a terminal of one of the set of electronic components to be measured that is not connected to another electronic component to be measured;
connecting a probe connected to the input of the measurement signal generation source to a terminal of the other electronic component to be measured of the set of electronic components to be measured that is not connected to a terminal of the one electronic component to be measured;
A probe connected to the voltage detection unit is connected to a pair of terminals of each of the electronic components to be measured.
An impedance measurement method characterized by:

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