Impedance measurement system and impedance measurement method

Abstract

This impedance measurement system (1) is provided with an impedance measurement device (5) that measures the impedance of electronic components (21, 22) to be measured. The impedance measurement device (5) is provided with a measurement signal generation source (11), a current detection unit (13), and a voltage detection unit (15). A switch (30) is provided for connecting a current measurement line (54) between the measurement signal generation source (11) and the electronic component (22) to be measured and a current measurement line (46) between one of the output terminals of the current detection unit (13) and the electronic component (21) to be measured. According to the impedance measurement system (1) of the present invention, it is possible to improve the safety during measurement.

Description

Technical Field

[0001] The present invention relates to an impedance measurement system and an impedance measurement method. Background Art

[0002] As one method for measuring the impedance of conductor patterns, batteries, components, etc. (hereinafter referred to as "Device Under Test (DUT)") present on a circuit board, the four-terminal method is known. As an impedance measurement device using the four-terminal method, current measurement lines 410 and 420 for connecting one terminal 400a and 500a of each of the battery units 400 and 500 to a pair of output terminals (high-side terminal and low-side terminal: not shown) of a measurement signal source and voltage measurement lines 510 and 520 for connecting a pair of output terminals (not shown) of a voltmeter to both terminals 500a and 500b of the battery unit 500 are used to constitute it (see Figure 4 ). Further, the other terminals 400b and 500b of the battery units 400 and 500 are connected in series.

[0003] See Figure 5 The configuration of the above impedance measurement device will be described in detail. The impedance measurement system 600 is configured to include an impedance measurement device 615 and a scanner 613 connected to battery units 710 and 720 via current measurement lines (current cables) and voltage measurement lines (voltage cables). The impedance measurement device 615 is configured to include a measurement signal source 621 that generates a measurement signal, a voltmeter 625 as a voltage detection unit, and a galvanometer (not shown) as a current detection unit.

[0004] Specifically, as Figure 5 shown, in a state where switches 810, 820, 830, and 880 are turned on, a measurement current flows from the measurement signal source 621 through the current measurement line to the high-side terminals of the battery unit 710 and the battery unit 720 as measurement objects, the voltage between both terminals of the battery unit 710 is measured by the voltmeter 625, and the current value of the measurement current is measured by a galvanometer (not shown) connected to the measurement signal source 621. The impedance of the battery unit 710 is calculated based on the current value and the voltage value of the measurement current. Next, in a state where switches 820 and 830 are turned off and switches 860 and 870 are turned on, the voltage between both terminals of the battery unit 720 is measured by the voltmeter 625, and the current value of the measurement current is measured by a galvanometer (not shown) connected to the measurement signal source 621. The impedance of the battery unit 720 is calculated based on the current value and the voltage value of the measurement current.

[0005] According to the impedance measurement device using the four-terminal method, since the path of the measurement current and the loop thereof coincide within the measurement current path, the influence of the magnetic flux generated by the measurement current (electromagnetic induction) can be reduced. Therefore, the influence of electromagnetic induction caused by magnetic flux leakage generated in a part of the current measurement line near the terminal of the battery cell can be suppressed, and thus the influence on the internal impedance measurement of the battery cell due to magnetic flux leakage can be suppressed.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2011-257340 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] However, in the production line of battery cells, since a plurality of battery cells are not connected separately, when performing the above impedance measurement, it is necessary to short-circuit all the single-side terminals of each battery cell (series connection), and sometimes problems may occur in terms of safety.

[0011] Therefore, an object of the present invention is to provide an impedance measurement system and an impedance measurement method that can improve the safety during measurement.

[0012] Solutions to the Problems

[0013] One aspect of the impedance measurement system of the present invention is an impedance measurement system having an impedance measurement device that measures the impedance of each measurement target electronic component. The impedance measurement device includes: a measurement signal generation source that supplies a measurement signal of a specified frequency to at least one set of the measurement target electronic components; a current detection unit that is disposed between one and the other of a pair of output terminals of the measurement signal generation source and detects the current flowing through the measurement target electronic component; and at least one voltage detection unit that measures the voltage generated between the two terminals of each of the one set of measurement target electronic components. The impedance measurement system is characterized in that

[0014] it has a connection unit that connects a first current measurement line and a second current measurement line, where the first current measurement line is the current measurement line between one of the pair of output terminals of the measurement signal generation source and one of the one set of measurement target electronic components, and the second current measurement line is the current measurement line between one of the pair of output terminals of the current detection unit and the other of the one set of measurement target electronic components.

[0015] Another aspect of the impedance measurement system of the present invention is characterized in that when measuring the voltage generated between the two terminals of one of a group of electronic components to be measured, the first current measurement line and the second current measurement line are connected via a connection unit.

[0016] Another aspect of the impedance measurement system of the present invention is characterized in that when multiple groups of a group of electronic components to be measured are provided, a signal selection unit is provided. The signal selection unit has a plurality of switches, and the plurality of switches are at least composed of a first switch group connected to the measurement signal generation source, a second switch group connected to the current detection unit, and a third switch group connected to the voltage detection unit. At least in a state where the current measurement line connected to the measurement signal generation source through the first switch group is connected to the high-side terminal of one or the other of the electronic components to be measured in a group of measurement target components, and the current measurement line connected to the current detection unit through the second switch group is connected to the low-side terminal of one or the other of the electronic components to be measured, and in a state where the voltage measurement line connected to one terminal of the voltage detection unit through the third switch group is connected to the high-side terminal of one or the other of the electronic components to be measured in a group of measurement target components and the voltage measurement line connected to the other terminal of the voltage detection unit is connected to the low-side terminal of one or the other of the electronic components to be measured, the voltage between the two terminals of one or the other of the electronic components to be measured in a group of measurement target components is detected by the voltage detection unit.

[0017] Another aspect of the impedance measurement system of the present invention is characterized in that when multiple groups of a group of electronic components to be measured are provided, the voltage detection unit is connected to each group of electronic components to be measured respectively whenever each group of electronic components to be measured is measured.

[0018] One aspect of the impedance measurement method of the present invention is an impedance measurement method in which a current detection unit detects the current flowing through an electronic component to be measured. The electronic component to be measured has at least a pair of terminals, and the electronic component to be measured is arranged between one and the other of a pair of output terminals of a measurement signal generation source that supplies a measurement signal of a specified frequency to at least one group of electronic components to be measured. At least one voltage detection unit measures the voltage generated between the two terminals of each of a group of electronic components to be measured, and the impedance of each electronic component to be measured is measured based on the detected current value of the current and the measured voltage value of the voltage. The impedance measurement method is characterized in that the first current measurement line and the second current measurement line are connected, where the first current measurement line is the current measurement line between one of the pair of output terminals of the measurement signal generation source and one of a group of electronic components to be measured, and the second current measurement line is the current measurement line between the other of the pair of output terminals of the current detection unit and the other of a group of electronic components to be measured.

[0019] Another aspect of the impedance measurement method of the present invention is characterized in that when measuring the voltage generated between the two terminals of one of a group of electronic components to be measured, the first current measurement line and the second current measurement line are connected via a connection unit.

[0020] Another aspect of the impedance measurement method of the present invention is characterized in that in the case where multiple groups of a group of electronic components to be measured are provided, a signal selection unit is provided. The signal selection unit has a plurality of switches, and the plurality of switches are at least composed of a first switch group connected to a measurement signal generation source, a second switch group connected to a current detection unit, and a third switch group connected to a voltage detection unit. At least connect the current measurement line connected to the measurement signal generation source via the first switch group to the high-side terminal of one or the other of the measurement object electronic components in a group of measurement object components, connect the current measurement line connected to the current detection unit via the second switch group to the low-side terminal of one or the other of the measurement object electronic components, connect the voltage measurement line of one terminal connected to the voltage detection unit to the high-side terminal of one or the other of the measurement object electronic components in a group of measurement object components, and connect the voltage measurement line of the other terminal connected to the voltage detection unit to the low-side terminal of the one or the other of the measurement object electronic components. The voltage detection unit detects the voltage between the two terminals of one or the other of the measurement object electronic components in a group of measurement object components.

[0021] Advantages of the Invention

[0022] An impedance measurement system and an impedance measurement method that can improve the safety during measurement can be provided. Brief Description of the Drawings

[0023] Figure 1 It is a diagram showing the configuration of the impedance measurement system according to the first embodiment of the present invention and showing the first connection configuration.

[0024] Figure 2 It is a diagram showing the configuration of the impedance measurement system according to the second embodiment of the present invention and showing the second connection configuration.

[0025] Figure 3 It is a diagram showing the configuration of the impedance measurement system according to the third embodiment of the present invention and showing the third connection configuration.

[0026] Figure 4 It is a diagram showing the configuration of a conventional impedance measurement system.

[0027] Figure 5 It is a diagram showing a more detailed configuration of a conventional impedance measurement system. Detailed Embodiments

[0028] <First Embodiment>

[0029] Hereinafter, with reference to Figure 1 A first embodiment of the impedance measurement system of the present invention will be described. It should be noted that the electronic component to be measured by the impedance measurement system (hereinafter referred to as "measurement object") is a battery cell or an element constituting a circuit. In the impedance measurement, the impedance, which is an important electrical parameter for evaluating the characteristics of the battery cell or the element, is measured. In the present embodiment, a battery cell is taken as an example of the measurement object. The present invention is characterized in the connection scheme between the impedance measurement device and the battery cells constituting the impedance measurement system. In connection with this, at least two battery cells are required and are arranged to overlap each other at a short distance. It should be noted that in this first embodiment, a set of battery cells, that is, battery cells arranged to overlap each other at a short distance, is taken as an example of the measurement object, but it can also be applied to other elements such as elements constituting a circuit, etc.

[0030] [Configuration of the impedance measurement system]

[0031] The impedance measurement system 1 is configured to include a scanner (signal selection unit) 3 connected to battery cells 21 and 22 via current measurement lines 45, 46, 54, 56 and voltage measurement lines 47, 48, 57, 58, and an impedance measurement device 5 connected to the scanner 3 via current measurement lines 25, 26 and voltage measurement lines 27, 28. The current measurement lines 25, 45, 54 are Hi (high level) side current measurement lines (SOURCE Hi), and the current measurement lines 26, 46, 56 are Lo (low level) side current measurement lines (SOURCE Lo). The voltage measurement lines 27, 47, 57 are Hi side voltage measurement lines (SENSE Hi), and the voltage measurement lines 28, 48, 58 are Lo side voltage measurement lines (SENSE Lo).

[0032] Here, different from the above embodiment, the current measurement lines 25, 45, 54 can be set as Lo side current measurement lines, the current measurement lines 26, 46, 56 can be set as Hi side current measurement lines, the voltage measurement lines 27, 47, 57 can be set as Lo side voltage measurement lines, and the voltage measurement lines 28, 48, 58 can be set as Hi side voltage measurement lines, swapping the Lo side and the Hi side with each other. In this case, the tab terminal 21a of the battery 21 of CH1 becomes the Lo side terminal, and the tab terminal 21b becomes the Hi side terminal. The tab terminal 22a of the battery 22 of CH2 becomes the Lo side terminal, and the tab terminal 22b becomes the Hi side terminal. The swapping of the Hi side terminal and the Lo side terminal can also be performed in the second embodiment and the third embodiment described later, but the above description is omitted here for the sake of convenience. It should be noted that the scanner 3 corresponds to the signal selection unit of claim 3.

[0033] The impedance measurement device 5 is configured to include a measurement signal source 11 that generates a measurement signal, a galvanometer 13 as a current detection unit, and a voltmeter 15 as a voltage detection unit. It should be noted that the measurement signal source 11 corresponds to the measurement signal generation source of claim 1.

[0034] As Figure 1 shown, the scanner 3 is equipped with switches 30 to 38 as signal selection units, and the on / off (switching) of switches 30 to 38 is performed.

[0035] [Connection scheme of the measurement device 5 with the battery units 21 and 22]

[0036] Hereinafter, in the connection scheme of the impedance measurement device 5, the scanner 3, and the battery units 21 and 22 to be measured, the connection scheme of the voltage measurement line and the connection scheme of the current measurement line will be described. When measuring the internal impedance of each of the battery units 21 and 22 to be measured by the impedance measurement device 5, the measurement signal source 11, the galvanometer 13, and the voltmeter 15 are connected to the battery units 21 and 22 via the scanner 3.

[0037] <Connection scheme of the voltage measurement line of the battery unit 21 of CH1>

[0038] By respectively turning on switches 31 and 32 of the scanner 3, the voltage measurement lines 27 and 28 are respectively connected to the voltage measurement lines 47 and 48, and the voltmeter 15 is connected to the battery unit 21. Moreover, one of a pair of output terminals (not shown) of the voltmeter 15 is connected to the tab terminal 21a of the battery unit 21 via the voltage measurement lines 27 and 47, and the other of the pair of output terminals of the voltmeter 15 is connected to the tab terminal 21b of the battery unit 21 via the voltage measurement lines 28 and 48. This connection scheme is a scheme for measuring the internal impedance of the battery unit 21. The measurement method will be described later.

[0039] <Connection scheme of the voltage measurement line of the battery unit 22 of CH2>

[0040] By respectively turning on switches 37 and 38 of the scanner 3, the voltage measurement lines 27 and 28 are respectively connected to the voltage measurement lines 57 and 58, and the voltmeter 15 is connected to the battery unit 22. Moreover, one of a pair of output terminals (not shown) of the voltmeter 15 is connected to the tab terminal 22a of the battery unit 22 via the voltage measurement lines 27 and 57, and the other of the pair of output terminals of the voltmeter 15 is connected to the tab terminal 22b of the battery unit 22 via the voltage measurement lines 28 and 58. This connection scheme is a scheme for measuring the internal impedance of the battery unit 22. The measurement method will be described later.

[0041] <Connection scheme of the current measurement line>

[0042] The current measurement line 25 and the current measurement line 45 are connected by turning on the switch 33 of the scanner 3, the current measurement line 26 and the current measurement line 46 are connected by turning on the switch 34, the current measurement line 25 and the current measurement line 54 are connected by turning on the switch 35, and the current measurement line 26 and the current measurement line 56 are connected by turning on the switch 36.

[0043] When measuring the impedance of the battery cells 21 and 22, the switches 33 and 36 of the scanner 3 are turned on, so that one of a pair of output terminals (not shown) of the measurement signal source 11 is connected to the tab terminal 21a of the battery cell 21 via the current measurement lines 25 and 45, and the other of the pair of output terminals of the measurement signal source 11 is connected to the tab terminal 22b of the battery cell 22 via the ammeter 13, the current measurement lines 26 and 56.

[0044] Here, the tab terminal 21b of the battery cell 21 is connected to the tab terminal 22a of the battery cell 22 via the switch 30. By turning on the switch 30 of the scanner 3, a measurement current loop is formed by the current measurement lines 25, 45, 46, 54, and 56. As a result, the direction of the measurement current flowing through the battery cell 21 and the direction of the measurement current flowing through the battery cell 22 become opposite directions. It should be noted that the switch 30 corresponds to the connection unit of claim 1.

[0045] The voltmeter 15 is disposed between the end of the voltage measurement line 27 and the end of the voltage measurement line 28, and measures the voltage generated between the end of the voltage measurement line 47 and the end of the voltage measurement line 48 due to the measurement current flowing through the above-mentioned measurement current loop. The measured voltage is output to an arithmetic processing unit (not shown). This voltage measurement is performed according to the above-mentioned connection scheme of the voltage measurement lines respectively during the impedance measurement of the battery cells 21 and 22 on the basis of the connection of the above-mentioned current measurement lines.

[0046] [Measurement method]

[0047] Regarding the impedance measurement of the battery cell 21 (corresponding to the first connection scheme), in the arithmetic processing unit, based on the current value of the measurement current (the current flowing through the battery cell 21) measured by the ammeter 13 and the voltage value of the voltage generated across the battery cell 21, the internal impedance of the battery cell 21 is calculated. As a prerequisite, the switches 30, 31, 32, 33, and 36 of the scanner 3 need to be turned on.

[0048] Regarding the impedance measurement of the battery cell 22 (corresponding to the second connection scheme), in the arithmetic processing unit, based on the current value of the measurement current (the current flowing through the battery cell 22) measured by the ammeter 13 and the voltage value of the voltage generated across the battery cell 22, the internal impedance of the battery cell 22 is calculated. As a prerequisite, the switches 30, 33, 36, 37, and 38 of the scanner 3 need to be turned on.

[0049] Figure 1 Taking a set of battery cells as an example, it has been described. However, in multiple sets of battery cells, as long as the switching implemented by the switch is performed as described above whenever the battery cells to be measured are changed, the impedance measurement can be sequentially performed. Specifically, it will be described in the second embodiment described later.

[0050] [Effect]

[0051] According to the impedance measurement system of the above-described first embodiment, the switch 30 is provided in the scanner 3, and through the connection process in the scanner 3, using a set of battery cells (a pair of battery cells as a set), the directions of the currents flowing through the respective battery cells of the pair of battery cells are different. Therefore, when measuring the impedance of each battery cell constituting the battery, the internal impedance of each battery cell can be safely measured without short-circuiting the battery cells on the battery side.

[0052] In addition, when measuring the internal impedance, the loop length of the measurement current loop flowing from the measurement signal source 11 that applies the measurement current through the battery cells 21 and 22 is also the same as that of the measurement current loop in the past (refer to Figure 5 )). Therefore, the suppression of the magnetic flux leakage loop brought about by the minimization of the loop length can be maintained, and the internal impedance of the battery cells 21 and 22 can be safely measured. It should be noted that the same effects as those described above can also be obtained in cylindrical, square cells other than the laminated battery cells, and measurement objects other than batteries.

[0053] <Second Embodiment>

[0054] Hereinafter, refer to Figure 2A second embodiment of the impedance measurement system of the present invention will be described. The difference from the above-described first embodiment lies in that two sets (a total of 4CH) are provided for a pair of battery units and the number of switches (19) constituting the scanner accordingly. It should be noted that, compared with the impedance measurement system of the above-described first embodiment, the number of connection schemes is increased in this second embodiment, but the basic concept is the same. That is, the basic concept is to provide switches 90, 109, 119 (switch 30 in the above-described first embodiment) for short-circuiting one side and the other side of a set of battery units, and during measurement, short-circuit the Hi-side current measurement line (SOURCE Hi) of one side and the Lo-side current measurement line (SOURCE Lo) of the other side of a set of battery units (the battery units of CH1 and CH2 in the first embodiment), and connect the Hi-side voltage measurement line (SENSE Hi) and the Lo-side voltage measurement line (SENSE Lo) of the battery unit to be measured to a voltmeter to perform impedance measurement. It should be noted that switches 93, 95, 101, 103 correspond to the first switch group of claim 3, switches 94, 96, 102, 104 correspond to the second switch group of claim 3, and switches 91, 92, 97, 98, 99, 100, 105, 106 correspond to the third switch group of claim 3.

[0055] Therefore, in this second embodiment, among the combinations of a pair of battery units, there are three combinations (three groups), namely, the battery unit 221 of CH1 and the battery unit 222 of CH2, the battery unit 222 of CH2 and the battery unit 223 of CH3, and the battery unit 223 of CH3 and the battery unit 224 of CH4. And in the impedance measurement of battery units 221 to 224, in order to measure the terminal voltages of the four battery units to be measured respectively, the voltmeter is connected to the battery unit to be measured during each measurement. Therefore, there are four connection schemes for the voltage measurement lines. Specifically, when the combination of battery units 221 and 222 is set as the measurement object, during measurement, connections for measuring the terminal voltages of battery units 221 and 222 respectively are required (two schemes).

[0056] In addition, when the measurement target is a combination of battery cells 222 and 223, during measurement, a connection for measuring the voltage across battery cell 223 is required (one scheme) (since the measurement of the voltage across battery cell 222 has been performed previously and thus is not required). In addition, when the measurement target is a combination of battery cells 223 and 224, during measurement, a connection for measuring the voltage across battery cell 224 is required (one scheme) (since the measurement of the voltage across battery cell 223 has been performed previously and thus is not required). As a result, there are four schemes in terms of the number of CHs for the voltage measurement scheme in the impedance measurement of battery cells 221 to 224.

[0057] In the following description, the above points are taken into consideration. It should be noted that battery cells 221 and 222 and battery cells 223 and 224 are actually arranged close to each other, but in Figure 2 the figure, they are shown at a predetermined interval due to the drawing relationship.

[0058] [Configuration of Impedance Measurement System]

[0059] The impedance measurement system 60 is configured to include a scanner (signal selection unit) 63 connected to battery cells 221 to 224 via current measurement lines 115, 116, 125, 126, 135, 136, 145, 146 and voltage measurement lines 117, 118, 127, 128, 137, 138, 147, 148, and an impedance measurement device 55 connected to the scanner 63 via current measurement lines 85, 86 and voltage measurement lines 87, 88. Current measurement lines 85, 115, 125, 135, 145 are Hi-side current measurement lines (SOURCE Hi), and current measurement lines 86, 116, 126, 136, 146 are Lo-side current measurement lines (SOURCE Lo). Voltage measurement lines 87, 117, 127, 137, 147 are Hi-side voltage measurement lines (SENSE Hi), and voltage measurement lines 88, 118, 128, 138, 148 are Lo-side voltage measurement lines (SENSE Lo). It should be noted that the scanner 63 corresponds to the signal selection unit of claim 3.

[0060] The impedance measurement device 55 is configured to include a measurement signal source 71 that generates a measurement signal, a current meter 73 as a current detection unit, and a voltmeter 75 as a voltage detection unit. It should be noted that the measurement signal source 71 corresponds to the measurement signal generation source of claim 1.

[0061] As Figure 2 shown, the scanner 63 includes switches 90 to 106, 109, 119 as signal selection units, and performs on / off (switching) of switches 90 to 106, 109, 119.

[0062] [Connection Scheme of Measuring Device 55 and Battery Cells 221 to 224]

[0063] Hereinafter, in the connection scheme of the impedance measuring device 55, the scanner 63, and the battery cells 221 to 224 to be measured, the connection scheme of the voltage measurement line and the connection scheme of the current measurement line will be described. When measuring the internal impedance of each of the battery cells 221 to 224 to be measured by the impedance measuring device 55, the measurement signal source 71, the ammeter 73, the voltmeter 75 are connected to the battery cells 221 to 224 via the scanner 63.

[0064] <Connection Scheme of Voltage Measurement Line for Battery Cell 221 of CH1>

[0065] By respectively turning on the switches 91 and 92 of the scanner 63, the voltage measurement lines 87 and 88 are respectively connected to the voltage measurement lines 117 and 118, and the voltmeter 75 is connected to the battery cell 221. Moreover, one of the pair of output terminals (not shown) of the voltmeter 75 is connected to the tab terminal 221a of the battery cell 221 via the voltage measurement lines 87 and 117, and the other of the pair of output terminals of the voltmeter 75 is connected to the tab terminal 221b of the battery cell 221 via the voltage measurement lines 88 and 118. This first connection scheme is a scheme for measuring the internal impedance of the battery cell 221. The measurement method is the same as that of the above first embodiment, so the description is omitted. Regarding the following connection schemes of the voltage measurement lines, the description of the measurement method is also omitted.

[0066] <Connection Scheme of Voltage Measurement Line for Battery Cell 222 of CH2>

[0067] By respectively turning on the switches 96 and 97, the voltage measurement lines 87 and 88 are respectively connected to the voltage measurement lines 127 and 128, and the voltmeter 75 is connected to the battery cell 222. Moreover, one of the pair of output terminals (not shown) of the voltmeter 75 is connected to the tab terminal 222a of the battery cell 222 via the voltage measurement lines 87 and 127, and the other of the pair of output terminals of the voltmeter 75 is connected to the tab terminal 222b of the battery cell 222 via the voltage measurement lines 88 and 128. This connection scheme is a scheme for measuring the internal impedance of the battery cell 222.

[0068] <Connection Scheme of Voltage Measurement Line for Battery Cell 223 of CH3>

[0069] By respectively closing switches 99 and 100, voltage measurement lines 87 and 88 are respectively connected to voltage measurement lines 137 and 138, and the voltmeter 75 is connected to the battery cell 223. Moreover, one of a pair of output terminals (not shown) of the voltmeter 75 is connected to the tab terminal 223a of the battery cell 223 via voltage measurement lines 87 and 137, and the other of the pair of output terminals of the voltmeter 75 is connected to the tab terminal 223b of the battery cell 223 via voltage measurement lines 88 and 138. This connection scheme is a scheme for measuring the internal impedance of the battery cell 223.

[0070] <Connection scheme of voltage measurement lines for the battery cell 224 of CH4>

[0071] By respectively closing switches 105 and 106, voltage measurement lines 87 and 88 are respectively connected to voltage measurement lines 147 and 148, and the voltmeter 75 is connected to the battery cell 224. Moreover, one of a pair of output terminals (not shown) of the voltmeter 75 is connected to the tab terminal 224a of the battery cell 224 via voltage measurement lines 87 and 147, and the other of the pair of output terminals of the voltmeter 75 is connected to the tab terminal 224b of the battery cell 224 via voltage measurement lines 88 and 148. This connection scheme is a scheme for measuring the internal impedance of the battery cell 224.

[0072] <Connection scheme of current measurement lines>

[0073] By closing the switch 93 of the scanner 63, the current measurement line 85 and the current measurement line 115 are connected, and by closing the switch 94, the current measurement line 86 and the current measurement line 116 are connected. By closing the switch 95, the current measurement line 85 and the current measurement line 125 are connected, and by closing the switch 96, the current measurement line 86 and the current measurement line 126 are connected. By closing the switch 101, the current measurement line 85 and the current measurement line 135 are connected, and by closing the switch 102, the current measurement line 86 and the current measurement line 136 are connected. By closing the switch 103, the current measurement line 85 and the current measurement line 145 are connected, and by closing the switch 104, the current measurement line 86 and the current measurement line 146 are connected.

[0074] [Measurement of the impedance of battery cells 221 and 222]

[0075] When measuring the impedance of battery cell 221, switches 90, 93, and 96 of scanner 63 are turned on. One of the pair of output terminals (not shown) of measurement signal source 71 is connected to tab terminal 221a of battery cell 221 via current measurement lines 85 and 115, and the other of the pair of output terminals of measurement signal source 71 is connected to tab terminal 222b of battery cell 222 via ammeter 73, current measurement lines 86 and 126. Then, switches 91 and 92 of scanner 63 are respectively turned on. One of the pair of output terminals (not shown) of voltmeter 75 is connected to tab terminal 221a of battery cell 221, and the other of the pair of output terminals of voltmeter 75 is connected to tab terminal 221b of battery cell 221 to perform impedance measurement of battery cell 221. It should be noted that when measuring the impedance of battery cell 221, switches other than switches 90, 91, 92, 93, and 96 of scanner 63 are turned off.

[0076] In addition, when measuring the impedance of battery cell 222, switches 90, 93, and 96 of scanner 63 are turned on. One of the pair of output terminals (not shown) of measurement signal source 71 is connected to tab terminal 221a of battery cell 221, and the other of the pair of output terminals of measurement signal source 71 is connected to tab terminal 222b of battery cell 222. Then, switches 97 and 98 of scanner 63 are respectively turned on. One of the pair of output terminals (not shown) of voltmeter 75 is connected to tab terminal 222a of battery cell 222, and the other of the pair of output terminals of voltmeter 75 is connected to tab terminal 222b of battery cell 222 to perform impedance measurement of battery cell 222. It should be noted that when measuring the impedance of battery cell 222, switches other than switches 90, 93, 96, 97, and 98 of scanner 63 are turned off.

[0077] Here, tab terminal 221b of battery cell 221 is connected to tab terminal 222a of battery cell 222 via switch 90. By turning on switch 90 of scanner 63, a measurement current loop is formed by current measurement lines 115, 116, 125, and 126. As a result, the direction of the measurement current flowing through battery cell 221 and the direction of the measurement current flowing through battery cell 222 become opposite directions.

[0078] [Impedance Measurement of Battery Cells 223 and 224]

[0079] When measuring the impedance of battery cell 223, switches 101, 104, and 119 of scanner 63 are turned on. One of the pair of output terminals (not shown) of measurement signal source 71 is connected to tab terminal 223a of battery cell 223 via current measurement lines 85 and 135, and the other of the pair of output terminals of measurement signal source 71 is connected to tab terminal 224b of battery cell 224 via ammeter 73, current measurement lines 86 and 146. Then, switches 99 and 100 of scanner 63 are turned on respectively. One of the pair of output terminals (not shown) of voltmeter 75 is connected to tab terminal 223a of battery cell 223, and the other of the pair of output terminals of voltmeter 75 is connected to tab terminal 223b of battery cell 223 to perform impedance measurement of battery cell 223. It should be noted that when measuring the impedance of battery cell 223, switches other than switches 99, 100, 101, 104, and 119 of scanner 63 are turned off.

[0080] In addition, when measuring the impedance of battery cell 224, switches 101, 104, and 119 of scanner 63 are turned on. One of the pair of output terminals (not shown) of measurement signal source 71 is connected to tab terminal 223a of battery cell 223 via current measurement lines 85 and 135, and the other of the pair of output terminals of measurement signal source 71 is connected to tab terminal 224b of battery cell 224 via ammeter 73, current measurement lines 86 and 146. Then, switches 105 and 106 of scanner 63 are turned on respectively. One of the pair of output terminals (not shown) of voltmeter 75 is connected to tab terminal 224a of battery cell 224, and the other of the pair of output terminals of voltmeter 75 is connected to tab terminal 224b of battery cell 224 to perform impedance measurement of battery cell 224. It should be noted that when measuring the impedance of battery cell 224, switches other than switches 101, 104, 105, 106, and 119 of scanner 63 are turned off.

[0081] Here, tab terminal 223b of battery cell 223 is connected to tab terminal 224a of battery cell 224 via switch 119. By turning on switch 119 of scanner 63, a measurement current loop is formed by current measurement lines 135, 136, 145, and 146. As a result, the direction of the measurement current flowing through battery cell 223 and the direction of the measurement current flowing through battery cell 224 become opposite directions.

[0082] A voltmeter 75 is disposed between the end of the voltage measurement line 87 and the end of the voltage measurement line 88, measures the voltage generated between the end of the voltage measurement line 117 and the end of the voltage measurement line 118 due to the measurement current flowing through the above-described measurement current loop, and the measured voltage is output to an arithmetic processing unit (not shown). This voltage measurement is performed based on the connection of the corresponding current measurement lines and according to the connection scheme of the corresponding voltage measurement lines in the cases where the measurement object of the impedance measurement is the battery cells 221 and 222 and the battery cells 223 and 224, respectively.

[0083] It should be noted that sometimes the measurement objects are the battery cells 222 and 223 of CH2 and CH3. Regarding the voltage measurement line connection scheme and the current measurement line connection scheme in this case, the switch 109 is turned on to form a measurement current loop including the Hi-side current measurement line 125 of the battery cell 222 of CH2, the Lo-side current measurement line 136 of the battery cell 223 of CH3, and the switch 109. Voltage measurement is performed for each battery cell of the measurement object, and impedance calculation is performed.

[0084] [Effect]

[0085] According to the impedance measurement system of the above-described second embodiment, a plurality of switches 90, 109, and 119 are provided in the scanner, and two sets of battery cells (a pair of battery cells is two sets) are used, and the directions of the currents flowing through each pair of battery cells are different. Therefore, even when performing impedance measurement of each battery cell of a battery composed of multiple sets with a large capacity, it is possible to safely measure the internal impedance of the battery cell without short-circuiting each battery cell.

[0086] <Third Embodiment>

[0087] Hereinafter, with reference to Figure 3 A third embodiment of the impedance measurement system of the present invention will be described. In the third embodiment, the Lo-side current measurement line 116 of the battery cell 221 of CH1 and the Hi-side current measurement line 125 of the battery cell 222 of CH2 are always connected via a connection line 150, the Lo-side current measurement line 126 of the battery cell 222 of CH2 and the Hi-side current measurement line 135 of the battery cell 223 of CH3 are always connected via a connection line 151, and the Lo-side current measurement line 136 of the battery cell 223 of CH3 and the Hi-side current measurement line 145 of the battery cell 224 of CH4 are always connected via a connection line 152. Except for the above differences, it is the same as the above-described second embodiment. The third embodiment is the same as the second embodiment except that the switches 90, 109, and 119 are not provided and the above configuration is adopted. Therefore, the same reference numerals are used for the same parts as those in the second embodiment for description.

[0088] In the above configuration, during measurement, the current measurement line (SOURCE Hi) on the Hi side of one of a set of battery cells (the battery cells of CH1 and CH2 in the first embodiment) is short-circuited with the current measurement line (SOURCE Lo) on the Lo side of the other. If the voltage measurement line (SENSE Hi) and the voltage measurement line (SENSE Lo) on the Hi side of the battery cell to be measured are connected to a voltmeter, the same effect as that in the second embodiment described above can be obtained.

[0089] It should be noted that if the number of switches of the scanner in the above-described embodiment is further increased, the number of sets of battery cells to be measured can of course be increased. In addition, the voltage measurement lines connected to the voltmeters 15 and 75 may be shielded wires instead of twisted cables.

[0090] [Effect]

[0091] As described above, according to the third embodiment of the present invention, in addition to the effects obtained by the impedance measurement system of the first embodiment, impedance measurement can be implemented with a simple configuration, so that a reduction in manufacturing cost can be achieved.

[0092] The specific embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. For example, the high-side terminal and the low-side terminal can be interchanged.

[0093] Explanation of reference numerals

[0094] 1, 60, 160: Impedance measurement system;

[0095] 3, 63: Scanner;

[0096] 5, 55: Impedance measurement device;

[0097] 11, 71: Measurement signal source;

[0098] 13, 73: Galvanometer;

[0099] 15, 75: Voltmeter;

[0100] 21, 22, 221, 222, 223, 224: Battery cell;

[0101] 21a, 22a, 121a, 122a, 221a, 222a, 223a, 224a, 21b, 22b, 121b, 122b, 221b, 222b, 223b, 224b, 225b: Tab terminal;

[0102] 25, 26, 45, 46, 54, 56: Current measurement lines;

[0103] 27, 28, 47, 48, 57, 58: Voltage measurement lines;

[0104] 31, 32, 33, 34, 35, 36, 37, 38, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 109, 119: Switches

[0105] 110, 111, 150, 151, 152: Short - circuit lines (connection lines).

Claims

1. An impedance measurement system, the impedance measurement system having an impedance measurement device for measuring the impedance of each electronic component to be measured, the impedance measurement device comprising: a measurement signal generator that supplies a measurement signal of a specified frequency to at least one set of electronic components to be measured, the electronic components to be measured having at least a pair of terminals; a current detection unit disposed between one and the other of a pair of output terminals of the measurement signal generator to detect the current flowing through the electronic components to be measured; and at least one voltage detection unit that measures the voltage generated between the two terminals of each of the set of electronic components to be measured, wherein the impedance measurement system is characterized in that it has a connection unit for connecting a first current measurement line and a second current measurement line, wherein the first current measurement line is a current measurement line between one of a pair of output terminals of the measurement signal generator and one of the set of electronic components to be measured, and the second current measurement line is a current measurement line between one of a pair of output terminals of the current detection unit and the other of the set of electronic components to be measured.

2. The impedance measurement system according to claim 1, characterized in that when measuring the voltage generated between the two terminals of one of the set of electronic components to be measured, the first current measurement line and the second current measurement line are connected via the connection unit.

3. The impedance measurement system according to claim 1 or 2, characterized in that when there are multiple sets of the set of electronic components to be measured, it is provided with a signal selection unit, the signal selection unit having a plurality of switches, the plurality of switches being composed of at least a first switch group connected to the measurement signal generator, a second switch group connected to the current detection unit, and a third switch group connected to the voltage detection unit, at least in a state where the current measurement line connected to the measurement signal generator through the first switch group is connected to the high-side terminal of the electronic component to be measured of one or the other of the set of electronic components, and the current measurement line connected to the current detection unit through the second switch group is connected to the low-side terminal of the electronic component to be measured of one or the other, and in a state where the voltage measurement line connected to one terminal of the voltage detection unit through the third switch group is connected to the high-side terminal of the electronic component to be measured of one or the other of the set of electronic components and the voltage measurement line connected to the other terminal of the voltage detection unit is connected to the low-side terminal of the electronic component to be measured of one or the other, the voltage detection unit detects the voltage between the two terminals of the electronic component to be measured of one or the other of the set of electronic components.

4. The impedance measurement system according to claim 3, characterized in that when there are multiple sets of the set of electronic components to be measured, the voltage detection unit is connected to each set of the electronic components to be measured respectively whenever measuring each set of the electronic components to be measured.

5. An impedance measurement method, in which a current detection unit detects a current flowing through an electronic component to be measured, wherein, the electronic component to be measured has at least a pair of terminals, the electronic component to be measured is disposed between one and the other of a pair of output terminals of a measurement signal generator, the measurement signal generator supplies a measurement signal of a specified frequency to at least one set of the electronic components to be measured, at least one voltage detection unit measures a voltage generated between the two terminals of each of the electronic components in the one set, and an impedance of each of the electronic components to be measured is measured based on a current value of the detected current and a voltage value of the measured voltage. The impedance measurement method is characterized in that, a first current measurement line is connected to a second current measurement line, wherein the first current measurement line is a current measurement line between one of the pair of output terminals of the measurement signal generator and one of the one set of the electronic components to be measured, and the second current measurement line is a current measurement line between the other of the pair of output terminals of the current detection unit and the other of the one set of the electronic components to be measured.

6. The impedance measurement method according to claim 5, characterized in that, when measuring a voltage generated between the two terminals of one of the one set of the electronic components to be measured, the first current measurement line and the second current measurement line are connected via a connection unit.

7. The impedance measurement method according to claim 5 or 6, characterized in that, when there are multiple sets of the one set of the electronic components to be measured, a signal selection unit is provided. The signal selection unit has a plurality of switches, and the plurality of switches are at least composed of a first switch group connected to the measurement signal generator, a second switch group connected to the current detection unit, and a third switch group connected to the voltage detection unit, at least the current measurement line connected to the measurement signal generator via the first switch group is connected to the high-side terminal of one or the other of the electronic components to be measured in the one set of the object components, the current measurement line connected to the current detection unit via the second switch group is connected to the low-side terminal of one or the other of the electronic components to be measured, the voltage measurement line connected to one terminal of the voltage detection unit via the third switch group is connected to the high-side terminal of one or the other of the electronic components to be measured in the one set of the object components, the voltage measurement line connected to the other terminal of the voltage detection unit is connected to the low-side terminal of one or the other of the electronic components to be measured, and the voltage detection unit detects a voltage between the two terminals of one or the other of the electronic components to be measured in the one set of the object components.

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