Impedance measurement system and impedance measurement method

Abstract

To provide an impedance measurement system and impedance measurement method which can improve safety in the time of measurement.SOLUTION: An impedance measurement system 1 includes an impedance measurement device 5 which includes a measurement signal generation source 11, a current detection unit 13 and a voltage detection unit 15, and which measures the impedance of measurement object electronic components 21, 22. The impedance measurement system includes a switch 30 for connecting a current measurement line 54 between the measurement signal generation source 11 and the measurement object electronic component 22 and a current measurement line 46 between one output terminal of the current detection unit 13 and the measurement object electronic component 21.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] The four-terminal method is known as one method for measuring the impedance of a conductor pattern, a battery, an element, etc. (hereinafter, these will be referred to as a "sample under test (DUT)") present on a circuit board. An impedance measurement device using the four-terminal method is configured using current measurement lines 410, 420 for connecting a pair of output terminals (high-side terminal and low-side terminal: not shown) of a measurement signal source to one terminal 400a, 500a of each of battery cells 400, 500, and voltage measurement lines 510, 520 for connecting a pair of output terminals (not shown) of a voltmeter to both terminals 500a, 500b of battery cell 500 (see FIG. 4). The other terminals 400b, 500b of each of battery cells 400, 500 are connected in series.

[0003] The configuration of the impedance measuring device described above will be described in detail with reference to Fig. 5. The impedance measuring system 600 includes an impedance measuring device 615 connected to battery cells 710, 720 via current measurement lines (current cables) and voltage measurement lines (voltage cables), and a scanner 613. The impedance measuring device 615 includes a measurement signal source 621 that generates a measurement signal, a voltmeter 625 as voltage detection means, and an ammeter (not shown) as current detection means.

[0004] 5 , with switches 810, 820, 830, and 880 turned on, a measurement current is passed from a measurement signal source 621 to the high-side terminals of battery cells 710 and 720 as measurement targets via current measurement lines, the voltage between both terminals of battery cell 710 is measured by a voltmeter 625, and the current value of the measurement current is measured by an ammeter (not shown) connected to the measurement signal source 621. The impedance of battery cell 710 is calculated based on the current and voltage values ​​of the measurement current. Next, with switches 820 and 830 turned off and switches 860 and 870 turned on, the voltage between both terminals of battery cell 720 is measured by the voltmeter 625, and the current value of the measurement current is measured by an ammeter (not shown) connected to the measurement signal source 621. The impedance of battery cell 720 is calculated based on the current and voltage values ​​of the measurement current.

[0005] According to the impedance measuring device using this four-terminal method, the outward and return paths of the measurement current are overlapped within the measurement current path, thereby reducing the influence of magnetic flux (electromagnetic induction) caused by the measurement current. Therefore, it is possible to suppress the influence of electromagnetic induction caused by magnetic flux leakage occurring in a part of the current measurement line near the terminal of the battery cell, thereby suppressing the influence of magnetic flux leakage loops on the internal impedance measurement of the battery cell. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-257340 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in a battery cell production line, multiple battery cells are not connected to each other, so when performing the impedance measurement described above, it is necessary to short-circuit (connect in series) all of the terminals on one side of each battery cell, which may pose a safety problem.

[0008] Therefore, an object of the present invention is to provide an impedance measurement system and an impedance measurement method that can improve safety during measurement. [Means for solving the problem]

[0009] One aspect of the impedance measurement system according to the present invention is an impedance measurement system having an impedance measurement device including a measurement signal generating source that supplies a measurement signal of a predetermined frequency to at least one set of electronic components under test, a current detection unit that is disposed between one of a pair of output terminals of the measurement signal generating source and the other and detects a current flowing through the electronic components under test, and at least one voltage detection unit that measures a voltage generated between both terminals of each of the set of electronic components under test, and measuring the impedance of each of the electronic components under test, The device is characterized by having a connection means for connecting a first current measurement line between one of a pair of output terminals of the measurement signal generating source and one of the set of electronic components to be measured, and a second current measurement line between one of the pair of output terminals of the current detection unit and the other of the set of electronic components to be measured.

[0010] Another aspect of the impedance measurement system of the present invention is characterized in that when measuring the voltage generated between both terminals of one of a pair of electronic components to be measured, the first current measurement line and the second current measurement line are connected via a connection means.

[0011] Another aspect of the impedance measurement system according to the present invention is characterized in that, when multiple sets of electronic components under test are arranged, the system includes a signal selection unit having a plurality of switches, the multiple switches comprising at least a first group of switches connected to a measurement signal source, a second group of switches connected to a current detection unit, and a third group of switches connected to a voltage detection unit, and the voltage detection unit detects a voltage between both terminals of one or both of the set of electronic components under test when at least the current measurement line connected to the measurement signal source by the first group of switches is connected to the high-side terminal of one or both of the set of electronic components under test, the current measurement line connected to the current detection unit by the second group of switches is connected to the low-side terminal of one or both of the set of electronic components under test, and the voltage measurement line connected to one terminal of the voltage detection unit is connected to the high-side terminal of one or both of the set of electronic components under test, and the voltage measurement line connected to the other terminal of the voltage detection unit is connected to the low-side terminal of the one or both of the set of electronic components under test, by the third group of switches.

[0012] Another aspect of the impedance measurement system of the present invention is characterized in that when multiple sets of electronic components to be measured are arranged, the voltage detection unit is connected to each set of electronic components to be measured for each measurement of the set of electronic components to be measured.

[0013] One aspect of the impedance measurement method of the present invention is an impedance measurement method in which a current detection unit detects a current flowing through an electronic component under test, the electronic component having at least a pair of terminals, and the electronic component under test is arranged between one of a pair of output terminals of a measurement signal generating source that supplies a measurement signal of a predetermined frequency to at least one set of electronic components under test, and at least one voltage detection unit measures a voltage generated between each of the terminals of the set of electronic components under test, and measures the impedance of each electronic component under test based on the current value of the detected current and the voltage value of the measured voltage, characterized in that a first current measurement line is connected between one of the pair of output terminals of the measurement signal generating source and one of the set of electronic components under test, and a second current measurement line is connected between the other of the pair of output terminals of the current detection unit and the other of the set of electronic components under test.

[0014] Another aspect of the impedance measurement method of the present invention is characterized in that when measuring the voltage generated between both terminals of one of a pair of electronic components to be measured, the first current measurement line and the second current measurement line are connected via a connection means.

[0015] Another aspect of the impedance measurement method of the present invention is characterized in that, when multiple sets of electronic components under test are arranged, the method includes a signal selection unit having a plurality of switches, and the multiple switches include at least a first group of switches connected to a measurement signal source, a second group of switches connected to a current detection unit, and a third group of switches connected to a voltage detection unit, and at least the current measurement line connected to the measurement signal source via the first group of switches is connected to a high-side terminal of one or other of the set of electronic components under test, the current measurement line connected to the current detection unit is connected to a low-side terminal of one or other of the set of electronic components under test via the second group of switches, the voltage measurement line connected to one terminal of the voltage detection unit is connected to a high-side terminal of one or other of the set of electronic components under test via the third group of switches, and the voltage measurement line connected to the other terminal of the voltage detection unit is connected to a low-side terminal of the one or other of the set of electronic components under test, and the voltage detection unit detects the voltage between both terminals of one or other of the set of electronic components under test. [Effects of the Invention]

[0016] It is possible to provide an impedance measurement system and an impedance measurement method that can improve safety during measurement. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram showing a configuration of an impedance measurement system according to a first embodiment of the present invention, illustrating a first connection configuration mode. [Figure 2] FIG. 10 is a diagram showing the configuration of an impedance measurement system according to a second embodiment of the present invention, illustrating a second connection configuration mode. [Figure 3] FIG. 10 is a diagram showing the configuration of an impedance measurement system according to a third embodiment of the present invention, illustrating a third connection configuration mode. [Figure 4] FIG. 1 is a diagram showing the configuration of a conventional impedance measurement system. [Figure 5]FIG. 1 is a diagram showing a more detailed configuration of a conventional impedance measurement system. DETAILED DESCRIPTION OF THE INVENTION

[0018] First Embodiment A first embodiment of an impedance measurement system according to the present invention will be described below with reference to FIG. 1. The electronic component to be measured (hereinafter referred to as the "measurement object") in the impedance measurement system is a battery cell or an element constituting an electric circuit, and impedance is measured as an important electrical parameter for evaluating the characteristics of the battery cell or element. In this embodiment, a battery cell will be used as the measurement object. The present invention is characterized by the connection between the impedance measurement device constituting the impedance measurement system and the battery cells, and in connection with this, at least two battery cells are required, and they are arranged overlapping each other at a close distance. In this first embodiment, a pair of battery cells arranged overlapping each other at a close distance will be described as the measurement object, but other elements, such as elements constituting an electric circuit, can also be used.

[0019] [Configuration of the impedance measurement system] The impedance measurement system 1 includes a scanner (signal selection unit) 3 connected to battery cells 21 and 22 via current measurement lines 45, 46, 54, and 56 and voltage measurement lines 47, 48, 57, and 58, and an impedance measurement device 5 connected to the scanner 3 via current measurement lines 25 and 26 and voltage measurement lines 27 and 28. The current measurement lines 25, 45, and 54 are Hi-side current measurement lines (SOURCE Hi), and the current measurement lines 26, 46, and 56 are Lo-side current measurement lines (SOURCE Lo). The voltage measurement lines 27, 47, and 57 are Hi-side voltage measurement lines (SENSE Hi), and the voltage measurement lines 28, 48, and 58 are Lo-side voltage measurement lines (SENSE Lo).

[0020] Here, different from the above-described embodiments, the current measurement lines 25, 45, 54 may be used as the Lo-side current measurement lines, the current measurement lines 26, 46, 56 may be used as the Hi-side current measurement lines, the voltage measurement lines 27, 47, 57 may be used as the Lo-side voltage measurement lines, the voltage measurement lines 28, 48, 58 may be used as the Hi-side voltage measurement lines, and the Lo-side and Hi-side may be interchanged with each other. In that case, the tab terminal 21a of the battery 21 of CH1 becomes the Lo-side terminal, 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. This interchange of the Hi-side terminal and the Lo-side terminal is similarly possible in the second and third embodiments described later, but for convenience, the above description is omitted there. Note that the scanner 3 corresponds to the signal selection unit of claim 3.

[0021] The impedance measurement device 5 includes a measurement signal source 11 that generates a measurement signal, a current meter 13 as a current detection unit, and a voltmeter 15 as a voltage detection unit. Note that the measurement signal source 11 corresponds to the measurement signal generation source of claim 1.

[0022] As shown in FIG. 1, the scanner 3 includes switches 30 to 38 as a signal selection unit, and turns on and off (switches) the switches 30 to 38.

[0023] [Connection mode between the measurement device 5 and the battery cells 21, 22] Hereinafter, in the connection mode between the impedance measurement device 5, the scanner 3, and the battery cells 21, 22 that are the measurement objects, the connection mode of the voltage measurement lines and the connection mode of the current measurement lines will be described. When measuring the internal impedance of each of the battery cells 21, 22 that are the measurement objects with the impedance measurement device 5, the measurement signal source 11, the current meter 13, and the voltmeter 15 are connected to the battery cells 21, 22 via the scanner 3.

[0024] [Connection mode of the voltage measurement lines of the battery cell 21 of CH1] By turning on each of the switches 31 and 32 of the scanner 3, the voltage measurement lines 27 and 28 and the voltage measurement lines 47 and 48 are respectively connected, and the voltmeter 15 and the battery cell 21 are connected. One of the pair of output terminals (not shown) of the voltmeter 15 is connected to the tab terminal 21a of the battery cell 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 cell 21 via the voltage measurement lines 28 and 48. This connection mode is for measuring the internal impedance of the battery cell 21. The measurement method will be described later.

[0025] <Voltage measurement line connection mode of the battery cell 22 of CH2> By turning on each of the switches 37 and 38 of the scanner 3, the voltage measurement lines 27 and 28 and the voltage measurement lines 57 and 58 are respectively connected, and the voltmeter 15 and the battery cell 22 are connected. One of the pair of output terminals (not shown) of the voltmeter 15 is connected to the tab terminal 22a of the battery cell 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 cell 22 via the voltage measurement lines 28 and 58. This connection mode is for measuring the internal impedance of the battery cell 22. The measurement method will be described later.

[0026] <Current measurement line connection mode> By turning on the switch 33 of the scanner 3, the current measurement lines 25 and 45 are connected, by turning on the switch 34, the current measurement lines 26 and 46 are connected, by turning on the switch 35, the current measurement lines 25 and 54 are connected, and by turning on the switch 36, the current measurement lines 26 and 56 are connected.

[0027] When measuring the impedance of battery cells 21 and 22, switches 33 and 36 of scanner 3 are turned on, and one of a pair of output terminals (not shown) of measurement signal source 11 is connected to tab terminal 21a of battery cell 21 via current measurement lines 25 and 45, and the other of the pair of output terminals of measurement signal source 11 is connected to tab terminal 22b of battery cell 22 via ammeter 13 and current measurement lines 26 and 56.

[0028] 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 is opposite to the direction of the measurement current flowing through the battery cell 22. The switch 30 corresponds to the connection means of claim 1.

[0029] The voltmeter 15 is disposed between the end of the voltage measurement line 27 and the end of the voltage measurement line 28, 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 in the measurement current loop, and outputs the measured voltage to an arithmetic processing unit (not shown). This voltage measurement is performed after the current measurement lines are connected as described above, and when measuring the impedance of the battery cells 21 and 22, it is performed according to the connection state of the voltage measurement lines as described above.

[0030] [Measurement method] Regarding the impedance measurement of the battery cell 21 (corresponding to the first connection mode), the internal impedance of the battery cell 21 is calculated in the arithmetic processing unit based on the current value of the measured current (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. As a prerequisite, the switches 30, 31, 32, 33, and 36 of the scanner 3 must be turned on.

[0031] Regarding the impedance measurement of the battery cell 22 (corresponding to the second connection mode), the internal impedance of the battery cell 22 is calculated in the arithmetic processing unit based on the current value of the measured current (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. As a prerequisite, the switches 30, 33, 36, 37, and 38 of the scanner 3 must be turned on.

[0032] 1 has been explained using an example of one set of battery cells, but even in the case of multiple sets of battery cells, impedance measurement can be performed sequentially by switching using the switch as described above each time the battery cell to be measured is changed. This will be specifically explained in the second embodiment to be described later.

[0033] [effect] According to the impedance measurement system of the first embodiment described above, a switch 30 is provided in the scanner 3, and a set of battery cells (one pair of battery cells) is used through connection processing within the scanner 3, and the direction of the current flowing through each of the pair of battery cells is made different.Therefore, when measuring the impedance of individual battery cells that make up a battery, the internal impedance of each battery cell can be measured safely without short-circuiting the battery cells on the battery side.

[0034] Furthermore, when measuring the internal impedance, the loop length of the measurement current loop that flows from measurement signal source 11 that applies the measurement current via battery cells 21 and 22 is the same as the loop length of the conventional measurement current loop (see FIG. 5), so it is possible to safely measure the internal impedance of battery cells 21 and 22 while maintaining suppression of magnetic flux leakage loops by minimizing the loop length. Note that the same effect as above can be obtained with cylindrical and prismatic cells other than laminated battery cells, and with measurement objects other than batteries.

[0035] <Second embodiment> A second embodiment of the impedance measurement system according to the present invention will be described below with reference to FIG. 2. This differs from the first embodiment in that two pairs of battery cells (4 channels in total) are provided and in the corresponding number of switches (19) constituting the scanner. The second embodiment has an increased number of connection configurations compared to the impedance measurement system according to the first embodiment. However, the basic concept is the same. Specifically, switches 90, 109, and 119 (switch 30 in the first embodiment) are provided to short-circuit one battery cell pair and the other battery cell pair. During measurement, the high-side current measurement line (SOURCE Hi) of one battery cell pair and the low-side current measurement line (SOURCE Lo) of the other battery cell pair (the battery cells of CH1 and CH2 in the first embodiment) are short-circuited, and the high-side voltage measurement line (SENSE Hi) and the low-side voltage measurement line (SENSE Lo) of the battery cell to be measured are connected to a voltmeter to perform impedance measurement. The switches 93, 95, 101, and 103 correspond to the first switch group of claim 3, the switches 94, 96, 102, and 104 correspond to the second switch group of claim 3, and the switches 91, 92, 97, 98, 99, 100, 105, and 106 correspond to the third switch group of claim 3.

[0036] Therefore, in the second embodiment, there are three combinations (three sets) of pairs of battery cells: battery cell 221 of CH1 and battery cell 222 of CH2; battery cell 222 of CH2 and battery cell 223 of CH3; and battery cell 223 of CH3 and battery cell 224 of CH4. In impedance measurement of battery cells 221 to 224, a voltmeter is connected to the battery cell to be measured at each measurement to measure the voltage across each of the four battery cells to be measured, so there are four connection modes for the voltage measurement lines. Specifically, when the combination of battery cells 221 and 222 is the measurement target, two connection modes are required to measure the voltage across each of battery cells 221 and 222.

[0037] Furthermore, when the measurement target is a combination of battery cells 222 and 223, a connection (one mode) for measuring the voltage across battery cell 223 is required during measurement (because the measurement of the voltage across battery cell 222 has been performed first and is therefore unnecessary). Furthermore, when the measurement target is a combination of battery cells 223 and 224, a connection (one mode) for measuring the voltage across battery cell 224 is required during measurement (because the measurement of the voltage across battery cell 223 has been performed first and is therefore unnecessary). Ultimately, there are four modes for voltage measurement, corresponding to the number of channels, in impedance measurement of battery cells 221 to 224.

[0038] The following explanation will be given with the above points in mind. Note that although battery cells 221 and 222 and battery cells 223 and 224 are actually arranged close to each other, they are shown separated by a predetermined distance in Figure 2 for convenience of illustration.

[0039] [Configuration of the impedance measurement system] The impedance measurement system 60 includes a scanner (signal selection unit) 63 connected to the battery cells 221 to 224 via current measurement lines 115, 116, 125, 126, 135, 136, 145, and 146 and voltage measurement lines 117, 118, 127, 128, 137, 138, 147, and 148, and an impedance measurement device 55 connected to the scanner 63 via current measurement lines 85 and 86 and voltage measurement lines 87 and 88. The current measurement lines 85, 115, 125, 135, and 145 are Hi-side current measurement lines (SOURCE Hi), and the current measurement lines 86, 116, 126, 136, and 146 are Lo-side current measurement lines (SOURCE Lo). Voltage measurement lines 87, 117, 127, 137, and 147 are Hi-side voltage measurement lines (SENSE Hi), and voltage measurement lines 88, 118, 128, 138, and 148 are Lo-side voltage measurement lines (SENSE Lo). The scanner 63 corresponds to the signal selection unit of claim 3.

[0040] The impedance measurement device 55 includes a measurement signal source 71 that generates a measurement signal, an ammeter 73 as a current detection unit, and a voltmeter 75 as a voltage detection unit. Note that the measurement signal source 71 corresponds to the measurement signal generation source of Claim 1.

[0041] As shown in FIG. 2, the scanner 63 includes switches 90 to 106, 109, 119 as signal selection units, and turns on and off (switches) the switches 90 to 106, 109, 119.

[0042] [Connection mode between the measurement device 55 and the battery cells 221 to 224] Hereinafter, in the connection mode among the impedance measurement device 55, the scanner 63, and the battery cells 221 to 224 to be measured, the connection mode of the voltage measurement line and the connection mode of the current measurement line will be described. When measuring the internal impedance of each of the battery cells 221 to 224 as the measurement object with the impedance measurement device 55, the measurement signal source 71, the ammeter 73, the voltmeter 75, and the battery cells 221 to 224 are connected via the scanner 63.

[0043] <Voltage measurement line connection mode of the battery cell 221 of CH1> By turning on each of the switches 91 and 90 of the scanner 63, the voltage measurement lines 87 and 88 and the voltage measurement lines 117 and 118 are respectively connected, and the voltmeter 75 and the battery cell 221 are connected. 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​​​​​By turning on each of switches 96 and 97, voltage measurement lines 87 and 88 and voltage measurement lines 127 and 128 are respectively connected, and voltmeter 75 and battery cell 222 are connected. One of the pair of output terminals (not shown) of voltmeter 75 is connected to tab terminal 222a of battery cell 222 via voltage measurement lines 87 and 127, and the other of the pair of output terminals of voltmeter 75 is connected to tab terminal 222b of battery cell 222 via voltage measurement lines 88 and 128. This connection mode is for measuring the internal impedance of battery cell 222.

[0045] <Voltage Measurement Line Connection Mode of Battery Cell 223 of CH3> By turning on each of switches 99 and 100, voltage measurement lines 87 and 88 and voltage measurement lines 137 and 138 are respectively connected, and voltmeter 75 and battery cell 223 are connected. One of the pair of output terminals (not shown) of voltmeter 75 is connected to tab terminal 223a of battery cell 223 via voltage measurement lines 87 and 137, and the other of the pair of output terminals of voltmeter 75 is connected to tab terminal 223b of battery cell 223 via voltage measurement lines 88 and 138. This connection mode is for measuring the internal impedance of battery cell 223.

[0046] <Voltage Measurement Line Connection Mode of Battery Cell 224 of CH4> By turning on each of switches 105 and 106, voltage measurement lines 87 and 88 and voltage measurement lines 147 and 148 are respectively connected, and voltmeter 75 and battery cell 224 are connected. One of the pair of output terminals (not shown) of voltmeter 75 is connected to tab terminal 224a of battery cell 224 via voltage measurement lines 87 and 147, and the other of the pair of output terminals of voltmeter 75 is connected to tab terminal 224b of battery cell 224 via voltage measurement lines 88 and 148. This connection mode is for measuring the internal impedance of battery cell 224.

[0047] <Current Measurement Line Connection Mode> Turning on switch 93 of scanner 63 connects current measurement line 85 and current measurement line 115, and turning on switch 94 connects current measurement line 86 and current measurement line 116. Turning on switch 95 connects current measurement line 85 and current measurement line 125, and turning on switch 96 connects current measurement line 86 and current measurement line 126. Turning on switch 101 connects current measurement line 85 and current measurement line 135, and turning on switch 102 connects current measurement line 86 and current measurement line 136. Turning on switch 103 connects current measurement line 85 and current measurement line 145, and turning on switch 104 connects current measurement line 86 and current measurement line 146.

[0048] [Impedance measurement of battery cells 221 and 222] When measuring the impedance of the battery cell 221, the switches 90, 93, and 96 of the scanner 63 are turned on, one of a pair of output terminals (not shown) of the measurement signal source 71 is connected to the tab terminal 221a of the battery cell 221 via the current measurement lines 85 and 115, and the other of the pair of output terminals of the measurement signal source 71 is connected to the tab terminal 222b of the battery cell 222 via the ammeter 73 and current measurement lines 86 and 126. Subsequently, the switches 91 and 92 of the scanner 63 are turned on, one of a pair of output terminals (not shown) of the voltmeter 75 is connected to the tab terminal 221a of the battery cell 221, 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, thereby measuring the impedance of the battery cell 221. Note that when measuring the impedance of the battery cell 221, all switches of the scanner 63 other than the switches 90, 91, 92, 93, and 96 are turned off.

[0049] Furthermore, when measuring the impedance of the battery cell 222, the switches 90, 93, and 96 of the scanner 63 are turned on to connect one of a pair of output terminals (not shown) of the measurement signal source 71 to the tab terminal 221a of the battery cell 221 and the other of the pair of output terminals of the measurement signal source 71 to the tab terminal 222b of the battery cell 222. Subsequently, the switches 97 and 98 of the scanner 63 are turned on to connect one of a pair of output terminals (not shown) of the voltmeter 75 to the tab terminal 222a of the battery cell 222 and the other of the pair of output terminals of the voltmeter 75 to the tab terminal 222b of the battery cell 222, thereby measuring the impedance of the battery cell 222. Note that when measuring the impedance of the battery cell 222, all switches other than the switches 90, 93, 96, 97, and 98 of the scanner 63 are turned off.

[0050] 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 are opposite to each other.

[0051] [Impedance measurement of battery cells 223 and 224] When measuring the impedance of the battery cell 223, switches 101, 104, and 119 of the scanner 63 are turned on, one of a pair of output terminals (not shown) of the measurement signal source 71 is connected to the tab terminal 223a of the battery cell 223 via current measurement lines 85 and 135, and the other of the pair of output terminals of the measurement signal source 71 is connected to the tab terminal 224b of the battery cell 224 via the ammeter 73 and current measurement lines 86 and 146. Subsequently, switches 99 and 100 of the scanner 63 are turned on, 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, 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, thereby measuring the impedance of the battery cell 223. Note that when measuring the impedance of the battery cell 223, all switches of the scanner 63 other than switches 99, 100, 101, 104, and 119 are turned off.

[0052] Furthermore, when measuring the impedance of the battery cell 224, the switches 101, 104, and 119 of the scanner 63 are turned on to connect one of a pair of output terminals (not shown) of the measurement signal source 71 to the tab terminal 223a of the battery cell 223 via the current measurement lines 85 and 135, and the other of the pair of output terminals of the measurement signal source 71 to the tab terminal 224b of the battery cell 224 via the ammeter 73 and current measurement lines 86 and 146. Subsequently, the switches 105 and 106 of the scanner 63 are turned on to connect one of a pair of output terminals (not shown) of the voltmeter 75 to the tab terminal 224a of the battery cell 224 and the other of the pair of output terminals of the voltmeter 75 to the tab terminal 224b of the battery cell 224, thereby measuring the impedance of the battery cell 224. Note that when measuring the impedance of the battery cell 224, all switches of the scanner 63 other than the switches 101, 104, 105, 106, and 119 are turned off.

[0053] 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 are opposite to each other.

[0054] Voltmeter 75 is disposed between the end of voltage measurement line 87 and the end of voltage measurement line 88, measures the voltage generated between the end of voltage measurement line 117 and the end of voltage measurement line 118 due to the measurement current flowing in the measurement current loop, and outputs the measured voltage to an arithmetic processing unit (not shown). When the measurement targets for impedance measurement are battery cells 221 and 222 and when they are battery cells 223 and 224, this voltage measurement is performed according to the connection mode of the corresponding voltage measurement lines after connecting the corresponding current measurement lines as described above.

[0055] In some cases, the measurement targets are battery cells 222, 223 of CH2 and CH3. In this case, the voltage measurement line connection mode and current measurement line connection mode are determined by turning on switch 109, forming a measurement current loop including current measurement line 125 on the Hi side of battery cell 222 of CH2, current measurement line 136 on the Lo side of battery cell 223 of CH3, and switch 109, and measuring the voltage for each battery cell to be measured to calculate the impedance.

[0056] [effect] According to the impedance measurement system of the second embodiment described above, the scanner is provided with multiple switches 90, 109, 119, and two sets of battery cells (two pairs of battery cells) are used to make the direction of current flowing through each pair of battery cells different. Therefore, even when measuring the impedance of individual battery cells that make up a battery consisting of multiple sets of large capacity batteries, the internal impedance of the battery cells can be measured safely without short-circuiting the individual battery cells.

[0057] <Third embodiment> A third embodiment of the impedance measurement system according to the present invention will be described below with reference to FIG. 3. In the third embodiment, the current measurement line 116 on the Lo side of the battery cell 221 in CH1 and the current measurement line 125 on the Hi side of the battery cell 222 in CH2 are constantly connected via a connection line 150, the current measurement line 126 on the Lo side of the battery cell 222 in CH2 and the current measurement line 135 on the Hi side of the battery cell 223 in CH3 are constantly connected via a connection line 151, and the current measurement line 136 on the Lo side of the battery cell 223 in CH3 and the current measurement line 145 on the Hi side of the battery cell 224 in CH4 are constantly connected via a connection line 152. Except for this difference, the third embodiment is the same as the second embodiment described above. The third embodiment is the same as the second embodiment except that switches 90, 109, and 119 are not provided and the configuration described above is used. Therefore, the same parts as those in the second embodiment will be described using the same reference numerals.

[0058] Even in the above configuration, if the Hi side current measurement line (SOURCE Hi) and the Lo side current measurement line (SOURCE Lo) of one of a pair of battery cells (the battery cells CH1 and CH2 in the first embodiment) are short-circuited during measurement, and the Hi side voltage measurement line (SENSE Hi) and the Lo side voltage measurement line (SENSE Lo) of the battery cell to be measured are connected to a voltmeter, the same effect as in the second embodiment described above can be obtained.

[0059] It goes without saying that if the number of switches constituting the scanner in the above-described embodiment 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 75 may be shielded wires instead of twisted cables.

[0060] [effect] As described above, according to the third embodiment, in addition to the effects obtained by the impedance measurement system of the first embodiment described above, impedance measurement can be performed with a simple configuration, thereby reducing manufacturing costs.

[0061] Although specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be implemented with various modifications within the scope of the present invention. For example, the high-side terminal and the low-side terminal can be interchanged. [Explanation of symbols]

[0062] 1,60,160 Impedance Measurement System 3,63 Scanner 5,55 Impedance measuring device 11,71 Measurement signal source 13,73 ammeter 15,75 Voltmeter 21,22,221,222,223,224 battery cells 21a, 22a, 121a, 122a, 221a, 222a 223a, 224a, 21b, 22b, 121b, 122b, 221b, 222b, 223b, 224b, 225b Tab terminals 25, 26, 45, 46, 54, 56 Current measurement wire 27, 28, 47, 48, 57, 58 Voltage measurement lines 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 110, 111, 150, 151, 152 Short-circuit wire (connection wire)

Claims

1. an electronic device under test having at least one pair of terminals, the measurement signal generating source supplying a measurement signal of a predetermined frequency to at least one pair of the electronic device under test; a current detection unit disposed between one of a pair of output terminals of the measurement signal generation source and detecting a current flowing through the electronic component under test; at least one voltage detection unit for measuring a voltage generated between both terminals of each of the set of electronic components to be measured; An impedance measurement system having an impedance measurement device for measuring the impedance of each of the electronic components to be measured, a connecting means for connecting a first current measurement line between one of the pair of output terminals of the measurement signal generating source and one of the set of electronic components under test, and a second current measurement line between one of the pair of output terminals of the current detecting unit and the other of the set of electronic components under test; An impedance measurement system comprising:

2. When measuring a voltage generated between both terminals of one of the pair of electronic components to be measured, the first current measurement line and the second current measurement line are connected via the connection means.

2. The impedance measurement system according to claim 1.

3. When a plurality of sets of the electronic components to be measured are provided, a signal selection unit having a plurality of switches is provided, and the plurality of switches are composed of at least a first group of switches connected to the measurement signal generating source, a second group of switches connected to the current detecting unit, and a third group of switches connected to the voltage detecting unit; At least in a state where a current measurement line connected to the measurement signal generating source by the first switch group is connected to a high-side terminal of one or the other of the set of electronic components to be measured, a current measurement line connected to the current detection unit by the second switch group is connected to a low-side terminal of one or the other of the electronic components to be measured, and a voltage measurement line connected to one terminal of the voltage detection unit is connected to a high-side terminal of one or the other of the set of electronic components to be measured by the third switch group, and a voltage measurement line connected to the other terminal of the voltage detection unit is connected to a low-side terminal of one or the other of the electronic components to be measured, the voltage detection unit detects a voltage between both terminals of one or the other of the set of electronic components to be measured.

3. The impedance measurement system according to claim 1, wherein the impedance measurement system is a measurement system for measuring impedance.

4. When a plurality of sets of the electronic components to be measured are arranged, the voltage detection unit is connected to each set of the electronic components to be measured for each measurement of the set of the electronic components to be measured.

4. The impedance measurement system according to claim 3.

5. An impedance measurement method comprising: a measurement target electronic component having at least a pair of terminals, the measurement target electronic component being disposed between one of a pair of output terminals of a measurement signal generating source that supplies a measurement signal of a predetermined frequency to at least one set of the measurement target electronic component; a current detection unit detecting a current flowing through the measurement target electronic component; at least one voltage detection unit measuring a voltage generated between both terminals of each of the set of measurement target electronic components; and measuring the impedance of each of the measurement target electronic components based on the current value of the detected current and the voltage value of the measured voltage, a first current measurement line between one of the pair of output terminals of the measurement signal generating source and one of the set of electronic components to be measured, and a second current measurement line between the other of the pair of output terminals of the current detection unit and the other of the set of electronic components to be measured; An impedance measurement method comprising:

6. When measuring a voltage generated between both terminals of one of the pair of electronic components to be measured, the first current measurement line and the second current measurement line are connected via a connection means.

6. The impedance measuring method according to claim 5.

7. When a plurality of sets of the electronic components to be measured are provided, a signal selection unit having a plurality of switches is provided, and the plurality of switches comprise at least a first group of switches connected to the measurement signal generating source, a second group of switches connected to the current detection unit, and a third group of switches connected to the voltage detection unit; At least, a current measurement line connected to the measurement signal generating source via the first switch group is connected to a high-side terminal of one or the other of the set of electronic components to be measured, a current measurement line connected to the current detection unit via the second switch group to a low-side terminal of one or the other of the electronic components to be measured; via the third switch group, a voltage measurement line connected to one terminal of the voltage detection unit is connected to a high-side terminal of one or the other of the set of electronic components to be measured, a voltage measurement line connected to the other terminal of the voltage detection unit is connected to a low-side terminal of one or the other of the electronic components to be measured; the voltage detection unit detects a voltage between both terminals of one or the other of the pair of electronic components under test; 7. The impedance measuring method according to claim 5 or 6.

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