JP2021081202A - Zero-adjustment correction method and impedance measurement method - Google Patents

Abstract

To provide a zero-adjustment correction method for enabling highly accurate zero-adjustment correction in an impedance measurement method by a four-terminal measurement method.SOLUTION: One and the other one of a pair of output terminals of a measurement signal source 10 are respectively connected to a terminal 31 of a battery cell 30 and the other terminal 35, so as to form a current route. One terminal of the voltmeter 20 is connected to the other terminal of the battery cell 30 via a connection loop 29 extending along an outer surface of the battery cell 30 while being insulated in terms of DC with respect to the one terminal of the battery cell 30. Then, the other terminal of the voltmeter 20 is connected to the other terminal of the battery cell 30 so as to perform zero-adjustment.SELECTED DRAWING: Figure 1

Description

The present invention relates to a zero adjustment correction method and an impedance measurement method.

As shown in FIG. 5, the impedance measuring device by the four-terminal measuring method has, as a basic configuration, a measuring signal source (constant current power supply) 100 that supplies a measuring current to a resistor to be measured (not shown), and a measuring signal source (constant current power supply) 100 thereof. It includes a voltmeter 200 for measuring the voltage drop generated in the resistor to be measured due to the measured current, and a calculation unit (not shown). For this impedance measurement, the current supply side terminal (SOURCE Hi) 101 on the Hi side connected to the positive electrode (Hi) of the measurement signal source 100 and the current supply side terminal (SOURCE) on the Lo side connected to the negative electrode (Lo) are used. Lo) 102, the total of the voltage detection terminal (SENSE Hi) 201 on the Hi side connected to the positive electrode (Hi) of the voltmeter 200 and the voltage detection terminal (SENCE Lo) 202 on the Lo side connected to the negative electrode (Lo). Four terminals are used.

Prior to the measurement, various corrections (adjustments) are performed, one of which is zero adjustment correction (also referred to as short correction) (see Patent Document 1 below). In the conventional zero adjustment correction method, for example, the current supply side terminal 101 and the current supply side terminal 102 are connected, the voltage detection terminal 201 and the voltage detection terminal 202 are connected, and the connected current supply side terminals 101 and 102 are connected. The connection mode was such that the voltage detection terminals 201 and 202 were connected at one point (see FIG. 5). Since the voltmeter 200 has a high input impedance, the measurement current Is supplied from the measurement signal source 100 flows through the current supply side terminals 101 and 102. Assuming that the current supply side terminals 101 and 102 and the voltage detection terminals 201 and 202 connected as described above are connected at one point and the voltage measured by the voltmeter 200 is V, the measured current Is is a constant current power supply. 100, it flows only through the so-called source lead wire passing through the current supply side terminal 101 and the current supply side terminal 102. Therefore, the voltage generated between the voltage detection terminal 201 and the voltage detection terminal 202 is 0 volt (V), and the impedance Z (= V / Is) between the voltage detection terminal 201 and the voltage detection terminal 202 is 0. In the zero adjustment correction, the measurement is performed with the voltage detection terminals 201 and 202 as 0Ω, and the impedance value calculated from the voltage V displayed on the voltmeter 200 and the measurement current Is at that time becomes an offset value, and the actual measurement is performed. At times, the offset value is subtracted, and the subtracted value is used as the measured impedance value after zero adjustment. The resistors R _SOH , R _SEH , R _SOL , and R _SEL are each wiring resistance and contact resistance.

Japanese Unexamined Patent Publication No. 2016-173274

However, as shown in FIG. 6, when measuring the battery cell 300, which is an electronic component to be measured, a measurement error occurs due to the following error factors. The first factor is that an induced voltage is generated in the voltmeter 200 due to the magnetic flux generated by the measured current (see FIG. 6), and this induced voltage causes a measurement error. The second factor is that the magnetic flux generated by the measured current Is causes an eddy current (see FIG. 6) in the battery exterior metal, and the magnetic flux generated by the eddy current causes an induced voltage in the voltmeter 200. However, this induced voltage causes a measurement error.

In this case, even if the zero adjustment is correctly performed by the above method, a new offset factor will occur at the time of battery measurement. By the way, there is known a method of making the zero adjust jig the same shape as the battery to be measured and zero adjusting, but in this case, it occurs because the path through which the measurement current flows is not the same between the zero adjust jig and the actual battery. Since the state of the magnetic flux applied is also different from that of the actual battery, the amount (effect amount) that affects the measurement error due to electromagnetic induction also differs. Furthermore, since the exterior of the battery itself is covered with metal, eddy currents are generated. Therefore, even if the zero-adjustment jig is constructed of dissimilar metals or non-magnetic materials, the amount that affects the above-mentioned measurement error will be different from that of the actual battery, so it is not possible to eliminate the measurement error during actual measurement. Have difficulty.

Therefore, an object of the present invention is to provide a zero-adjustment correction method that enables highly accurate zero-adjustment correction (short-circuit correction) in the impedance measurement method by the four-terminal measurement method.

One aspect of the zero-adjustment correction method according to the present invention is a voltage generated between a measurement signal source that supplies a measurement signal of a predetermined frequency to a measurement target electronic component having a pair of terminals and a voltage generated between both terminals of the measurement target electronic component. This is a zero-adjustment correction method in an impedance measuring device that measures the impedance of an electronic component to be measured, including a voltage detection unit to be measured. A current path is formed by connecting one terminal and the other terminal, and one terminal of the voltage detection unit is made to be DC-insulated from one terminal of the electronic component to be measured so that the electronic component to be measured is electrically insulated. Connect to the other terminal of the electronic component to be measured via a connecting line extending along the outer surface, and connect the other terminal of the voltage detector to the other terminal of the electronic component to be measured to perform zero adjustment. It is characterized by that.

Another aspect of the zero-adjustment correction method according to the present invention is a voltage generated between a measurement signal source that supplies a measurement signal of a predetermined frequency to a measurement target electronic component having a pair of terminals and a voltage generated between both terminals of the measurement target electronic component. This is a zero-adjustment correction method in an impedance measuring device that measures the impedance of an electronic component to be measured, including a voltage detection unit that measures the voltage. A state in which one terminal of an electronic component of the same type as the above is connected to the other terminal to form a current path, and one terminal of the voltage detection unit is DC-insulated from one terminal of the same type of electronic component. Connect to the other terminal of the same type of electronic component via a connecting line extending along the outer surface of the same type of electronic component, and connect the other terminal of the voltage detector to the other terminal of the same type of electronic component. It is characterized by performing zero adjustment.

Another aspect of the zero-adjustment correction method according to the present invention is the generation of a measurement signal that supplies a measurement signal of a predetermined frequency to the first to Nth (N is an integer of 2 or more) measurement target electronic components each having a pair of terminals. It includes a source and a voltage detector that measures the voltage generated between both terminals of the first to Nth measurement target electronic components, and measures the impedance of each of the first to Nth measurement target electronic components. This is a zero-adjustment correction method in an impedance measuring device, in which one and the other of a pair of output terminals of a measurement signal generation source are individually connected to one terminal and the other terminal of each of the first to Nth measurement target electronic components. It is connected to form a current path, and one terminal of the voltage detection unit is connected to one terminal of each of the first to Nth measurement target electronic components for each measurement of the first to Nth measurement target electronic components. The other terminal of the first to Nth measurement target electronic components via a connection line extending along the outer surface of each of the first to Nth measurement target electronic components in a DC-insulated state. It is characterized in that the other terminal of the voltage detection unit is connected to each of the other terminals of the first to Nth measurement target electronic components to execute zero adjustment.

Another aspect of the zero-adjustment correction method according to the present invention is the generation of a measurement signal that supplies a measurement signal of a predetermined frequency to the first to Nth (N is an integer of 2 or more) measurement target electronic components each having a pair of terminals. It includes a source and a voltage detector of the first to Nth (N is an integer of 2 or more) for measuring the voltage generated between both terminals of the electronic components to be measured 1st to Nth. This is a zero-adjustment correction method in an impedance measuring device that measures the impedance of each of the Nth measurement target electronic components, and one and the other of the pair of output terminals of the measurement signal generation source are the first to Nth measurement target electronic components. One terminal of each of the above and the other terminal is individually connected to form a current path, and one terminal of the first to Nth voltage detection units is connected to one of the first to Nth measurement target electronic components. The first to Nth measurement target electrons are respectively insulated from the terminals in a DC state via a connection line extending along the outer surface of each of the first to Nth measurement target electronic components. It is characterized by connecting to the other terminal of the component and connecting the other terminal of the first to Nth voltage detectors to the other terminal of the first to Nth measurement target electronic components to execute zero adjustment. And.

One aspect of the impedance measurement method according to the present invention is that after the above-mentioned zero adjustment correction method is performed, the state of being DC-insulated to one terminal of the electronic component to be measured is released, and the connection loop is connected to the electronic component to be measured. With the voltage detector removed, connect one terminal of the voltage detector to one terminal of the electronic component to be measured, and connect the other terminal of the voltage detector to the other terminal of the electronic component to be measured. It is characterized by measuring the impedance of.

In another aspect of the impedance measurement method according to the present invention, after the above-mentioned zero adjustment correction method is performed, the state of being DC-insulated to one terminal of an electronic component of the same type as the electronic component to be measured is released. With the connection wire removed from the same type of electronic component as the electronic component to be measured, connect one terminal of the voltage detector to one terminal of the electronic component to be measured, and connect the other terminal of the voltage detector to the electronic component to be measured. It is characterized in that it is connected to the other terminal to measure the impedance of the electronic component to be measured.

It is possible to provide an impedance measurement system and a measurement method that can reduce the influence of electromagnetic induction that occurs on a part of the voltage measurement line near the terminal to be measured due to magnetic flux leakage that occurs on a part of the current measurement line near the terminal to be measured. it can.

It is a figure which showed the connection structure mode for demonstrating the zero adjustment correction method which concerns on 1st Embodiment of this invention. It is a figure which showed the wiring pattern of the current measurement loop and the voltage measurement loop in carrying out the reproducibility test of the measured value. It is a graph which showed the result of the impedance measurement performed in the three kinds of wiring patterns of FIG. 2 using the zero adjustment jig which concerns on the 1st Embodiment in the reproducibility test of the measured value, and the conventional zero adjustment jig. .. It is a figure for demonstrating the zero adjustment correction method which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the conventional zero adjustment correction method. It is a figure which showed the connection structure mode for demonstrating the conventional zero adjustment correction method.

<First Embodiment>
Hereinafter, the first embodiment of the zero adjustment correction method according to the present invention will be described with reference to FIG. 1 by taking a battery cell as an example of measurement. The electronic component to be measured (hereinafter referred to as “measurement target”) of the impedance measuring device is a battery cell (battery cell) or an element constituting an electric circuit, and impedance measurement is a characteristic of the battery cell or the element. Measure impedance as an important electrical parameter for evaluation.

[Configuration of impedance measuring device]
The impedance measuring device 1 includes a measuring signal source 10 for generating a measuring signal, an ammeter 15 as a current detecting unit, and a voltmeter 20 as a voltage detecting unit. The measurement signal source 10 corresponds to the measurement signal generation source of claim 1.

[Connection mode between measuring device and battery cell]
The connection mode between the impedance measuring device 1 and the battery cell 30 to be measured will be described below. When measuring the impedance of the battery cell 30 with the impedance measuring device 1, the measurement signal source 10, the ammeter 15, the voltmeter 20 and the battery cell 30 are connected via the current measuring line 12 and the voltage measuring line 22. Here, regarding the probes, the voltage detection of the two current probes 25 and 26 included in the measurement current loop, which is the path of the current flowing from the measurement signal source 10 to the ammeter 15 via the battery cell 30, and the battery cell 30. Two voltage probes 27, 28 included in the voltage detection loop, which is the path of the above, are used. Further, a twisted cable 12 formed by twisting the current measuring lines 12a and 12b to each other is used as the electrical wiring of the current probes 25 and 26, and the voltage measuring lines 22a and 22b are twisted to each other as the electrical wiring of the voltage probes 27 and 28. The twisted cable 22 formed in the above is used.

The current measurement line 12a is a Hi-side source line (SOURCE Hi) and is connected to the current probe 25, and the current measurement line 12b is a Lo-side source line (SOURCE Lo) and is connected to the current probe 26. The voltage measurement line 22a is a Hi-side sense line (SENSE Hi) and is connected to the current probe 27, and the voltage measurement line 22b is a Lo-side sense line (SENSE Lo) and is connected to the current probe 28.

One of the pair of output terminals (not shown) of the measurement signal source 10 is connected to the tab terminal 31 of the battery cell 30 via the current measurement line 12a and the current probe 25, and is connected to the pair of output terminals of the measurement signal source 10. The other is connected to the tab terminal 35 of the battery cell 30 via an ammeter 15, a current measuring line 12b, and a current probe 26.

The voltmeter 20 is arranged between the end of the voltage measurement line 22a and the end of the voltage measurement line 22b on one end side of the twist cable 22, and measures the voltage due to the measurement current Is flowing in the measurement current loop. It has a function of measuring the _{voltage V 1} generated between the end of the wire 22a and the end of the voltage measuring wire 22b. The measured voltage V ₁ is output to an arithmetic processing unit (included in the measuring device 1) (not shown), and the R value and the X value of the impedance, which will be described later, are calculated.

[Zero adjustment jig configuration]
Hereinafter, the configuration of the zero adjustment jig used in the impedance measuring device for carrying out the zero adjustment correction method according to the present invention will be described.

Here, the zero-adjustment jig 36 used in the impedance measuring device for carrying out the zero-adjustment correction method according to the present invention is configured by using the battery 30 to be measured, and has a first feature of being a measurement target. A connection loop 29 formed by short-circuiting a Hi-side sense wire (SENSE Hi) and a Lo-side sense wire (SENSE Lo) between a pair of tab terminals 31 and 35 of a certain battery cell 30 is formed. The connection loop 29 has an end face orthogonal to the thickness direction of the tab terminal 35 (the side surface of the tab terminal orthogonal to the longitudinal direction of the battery cell 30) from the connection point 32 located at a predetermined distance from the tab terminal 31. It is formed along the cell surface of the battery cell 30 in a state of being close to the cell surface of the battery cell 30 toward the connection point 37 in the above. The connection point 32 corresponds to one terminal of the voltage detection unit of claim 1, and the connection point 37 corresponds to the other terminal of the electronic component to be measured according to claim 1.

As a second feature, on the Hi side of the battery cell 30, the connection point 33 at one end of the current measurement line 12a (Hi side source line) and the connection point 32 at one end of the voltage measurement line 22a (Hi side sense line) are direct current. Insulated in. That is, a capacitor 34 is interposed between the probe 25 and the probe 27 so that the potentials of the probe 25 and the probe 27 on the tab terminal 31 are directly insulated. Incidentally, a method other than interposing the capacitor 34 between the probe 25 and the probe 27 may be used as long as it can be insulated by direct current. Further, the connection point 33 corresponds to one terminal of the electronic component to be measured according to claim 1.

The zero-adjust jig used in the impedance measuring device for carrying out the above-mentioned conventional zero-adjust correction method has the same shape as the battery cell to be measured, and has a current path different from the current path through which the measured current flows. While the zero adjust jig is provided inside the adjust jig, the zero adjust jig used in the impedance measuring device for carrying out the zero adjust correction method according to the present invention is the same as the battery cell to be measured as described above. The two differ in that they have the same shape and the current path through which the measured current flows is the same.

[Measuring method]
Using the zero adjust jig 36, the current probe 25 and the voltage probe 27 constituting the measuring device 1 are connected to the connection point (node) 33 and the connection point 32 of the tab terminal 31, respectively, and the current probe 26 and the voltage probe 28 are connected, respectively. After connecting to the connection point 38 and the connection point 37 of the tab terminal 35, the measurement current Is supplied from the measurement signal source 10 is measured by the ammeter 15, and the voltage V generated between the connection point 32 and the connection point 37. ₁ is measured by the voltmeter 20. This zero adjustment was executed with the R value and X value (Z = R + jX; R value: resistance value, X value: reactance value) of the impedance calculated based on the measured voltage V and the measured current Is as offset values. Later, after removing the zero adjust jig 36 (the battery cell 30 in which the connection loop 29 is formed) and the capacitor 34, the voltage probe 27 is used when measuring the impedance of the battery cell 30 to be measured. Connect to the connection point 39 of the tab terminal 31 of the battery cell 30 (see the partially enlarged view at the time of impedance measurement on the lower right side of FIG. 1), and connect the Hi side sense wire 22a and the Lo side sense wire 22b through the inside of the battery cell 30. The R value and the X value of the impedance of the battery cell 30 are measured in the connected state. A value obtained by subtracting the above offset value from the R value and X value of the measured impedance is calculated, and the calculated value becomes the measured impedance (R value, X value) after executing zero adjustment. The current measurement line 12a is a Hi-side source line (SOURCE Hi) and is connected to the current probe 25, and the current measurement line 12b is a Lo-side source line (SOURCE Lo) and is connected to the current probe 26. The voltage measurement line 22a is a Hi-side sense line (SENSE Hi) and is connected to the voltage probe 27, and the voltage measurement line 22b is a Lo-side sense line (SENSE Lo) and is connected to the voltage probe 28.

[Measured value reproducibility test]
Below, the zero-adjustment jig 36 used in the impedance measuring device for carrying out the zero-adjustment correction method of the present invention, that is, the zero-adjustment jig 36 configured by using the battery cell 30 to be measured, and the above-mentioned conventional zero-adjustment jig 36. The reproducibility test of the measured value performed using the zero adjust jig having the same shape as the battery cell to be measured will be described. FIG. 3 is a graph showing the results of impedance measurement performed in three types of wiring patterns using the zero adjustment jig of the present embodiment and the conventional zero adjustment jig in the reproducibility test of measured values. The reason why the measurement was performed with three types of wiring patterns (see FIG. 2) is that the reproducibility can be determined more accurately by measuring with wiring patterns having different effects of electromagnetic induction.

In the reproducibility test, the current probe 25 and the voltage probe 27 constituting the impedance measuring device 1 are connected to the connection point 33 of the tab terminal 31 and the connection point, respectively, by using the zero adjustment jig 36 used in the zero adjustment correction method according to the present invention. After connecting to 32, the current probe 26 and the voltage probe 28 are connected to the connection point 38 and the connection point 37 of the tab terminal 35, respectively, and then connected to the measurement current Is supplied from the measurement signal source 10 and the connection point 32 at that time. _{The voltage V 1} generated between the points 37 is measured by the voltmeter 20, and zero adjustment is executed with the R value and X value of the impedance calculated based on the voltage V and the measured current Is as offset values. Then, after executing the zero adjustment, the zero adjustment jig 36 is removed. That is, when the connection loop 29 is removed from the battery cell 30, the capacitor 34 is also removed, and the impedance is measured with respect to the battery cell 30 to be measured, the voltage probe 27 is connected to the tab terminal 31 of the battery cell 30. The battery cell 30 is connected to the point 39 (see the partially enlarged view at the time of impedance measurement on the lower right side of FIG. 1) and the Hi side sense wire 22a and the Lo side sense wire 22b are connected via the inside of the battery cell 30. The impedance of the measured impedance is measured, and the value obtained by subtracting the above offset value from the measured R value and X value of the impedance is defined as the R value and X value of the measured impedance after zero adjustment.

In the above measurement, A1 in FIG. 3 refers to the loop surface (the surface of the region surrounded by the loop) of the wiring pattern 1 shown in the upper and lower left side views of FIG. 2, that is, the Hi side source line 12a and the Low side source line 12b. Hereinafter referred to as a “loop surface”) and the loop surfaces of the Hi side sense wire 22a and the Low side sense wire 22b are arranged on the left and right sides of the zero adjustment jig 36 using the battery cell 30. After performing zero adjustment, the connection loop 29 is removed, the capacitor 34 is also removed, and when impedance measurement is performed on the battery cell 30 to be measured, the voltage probe 27 is connected to the tab terminal 31 of the battery cell 30. Impedance is measured in a state where it is connected to point 39 (see the partially enlarged view at the time of impedance measurement on the lower right side of FIG. 1) and the Hi side sense wire 22a and the Lo side sense wire 22b are connected via the inside of the battery cell 30. The measured impedance (R value, X value) obtained in the above is shown. In addition, the Example based on the A1 wiring pattern will be referred to as "Example A1" hereafter.

In A2 of FIG. 3, the wiring pattern 2 shown in the upper and lower central views of FIG. 2, that is, the loop surface of the Hi side source line 12a and the low side source line 12b and the loop surface of the Hi side sense line 22a and the low side sense line 22b, respectively After executing the above-mentioned zero adjustment in a state where they are orthogonal to each other and arranged with the zero adjust jig 36 sandwiched between them, the connection loop 29 is removed, and the capacitor 34 is also removed, and then the battery cell 30 to be measured is measured. When the impedance is measured, the voltage probe 27 is connected to the connection point 39 of the tab terminal 31 of the battery cell 30 (see the partially enlarged view at the time of impedance measurement on the lower right side of FIG. 1) with the Hi side sense wire 22a. R value and X value (Z = R + jX; R value: resistance value, X value: reactance) of the measured impedance Z obtained by impedance measurement with the Lo side sense wire 22b connected via the inside of the battery cell 30. Value) is shown. In addition, the Example based on the A2 wiring pattern will be referred to as "Example A2" hereafter.

A3 of FIG. 3 shows the wiring pattern 3 shown in the upper and lower views on the right side of FIG. 2, that is, the loop surface of the Hi side source line 12a and the low side source line 12b and the loop surface of the Hi side sense line 22a and the low side sense line 22b, respectively. After executing the above-mentioned zero adjustment in a state where the zero adjustment jigs 36 are placed on top of each other and sandwiching the zero adjust jig 36, the connection loop 29 is removed, and the capacitor 34 is also removed, and then the battery cell 30 to be measured is subjected to the measurement. When the impedance is measured, the voltage probe 27 is connected to the connection point 39 of the tab terminal 31 of the battery cell 30 (see the partially enlarged view at the time of impedance measurement on the lower right side of FIG. 1), and the Hi side sense wire 22a and the Lo side. It shows the measured impedance (R value, X value) obtained by impedance measurement in a state where the sense wire 22b is connected via the inside of the battery cell 30. In addition, the example based on the A3 wiring pattern will be referred to as "Example A3" hereafter.

B1 of FIG. 3 has an internal structure after performing zero adjustment by the method shown in FIG. 5 (the zero adjustment method described in the above paragraph (0003)) or having the same shape as the battery cell to be measured. After performing zero adjustment with different zero adjustment jigs (zero adjust execution by the method described in paragraph (0006) above), the Hi side source line and Low side source line, the Hi side sense line, and the Low side sense line are measured. The measured impedance (R value, X value) obtained by reconnecting to the battery cell and measuring the impedance is shown. Here, the loop surfaces of the Hi-side source line and the Low-side source line and the loop surfaces of the Hi-side sense line and the Low-side sense line are arranged on the left and right sides of the battery cell (loop surfaces of each other). The arrangement state is the same as the lower left figure of FIG. 2). In addition, the Example based on the B1 wiring pattern will be referred to as "Example B1" hereafter.

B2 of FIG. 3 has an internal structure after performing zero adjustment by the method shown in FIG. 5 (the zero adjustment method described in the above paragraph (0003)) or having the same shape as the battery cell to be measured. After performing zero adjustment with different zero adjustment jigs (zero adjust execution by the method described in paragraph (0006) above), the Hi side source line and Low side source line, the Hi side sense line, and the Low side sense line are measured. The measured impedance (R value, X value) obtained by reconnecting to the battery cell and measuring the impedance is shown. Here, the loop surfaces of the Hi-side source line and the Low-side source line and the loop surfaces of the Hi-side sense line and the Low-side sense line are orthogonal to each other, and are arranged on the left and right sides of the battery cell. (The arrangement of the loop surfaces is the same as in the lower center of Fig. 2). In addition, the Example based on the B2 wiring pattern will be referred to as "Example B2" hereafter.

B3 of FIG. 3 has an internal structure after performing zero adjustment by the method shown in FIG. 5 (the zero adjustment method described in the above paragraph (0003)) or having the same shape as the battery cell to be measured. After executing zero adjustment with different zero adjustment jigs (execution of zero adjustment by the method described in the above paragraph (0006)), measure the Hi side source line and the Low side source line, the Hi side sense line and the Low side sense line. The measured impedance (R value, X value) obtained by reconnecting to the target battery cell and measuring the impedance is shown. Here, the loop surfaces of the Hi-side source line and the Low-side source line and the loop surfaces of the Hi-side sense line and the Low-side sense line are overlapped with each other, and are arranged so as to sandwich the battery cell (). The arrangement of the loop surfaces is the same as in the lower right side of FIG. 2). In addition, the Example based on the B3 wiring pattern will be referred to as "Example B3" hereafter.

The results of the measured value reproducibility test will be considered below. As shown in FIG. 3, the R value in the impedance measurement using the zero adjustment jig 36 used in the zero adjustment correction method according to the present invention is 6.29 (mΩ) to 6.31 (mΩ) to 6.31 in Examples A1 to A3. While it was in the range of mΩ), the R value in the impedance measurement using the conventional zero adjustment jig was in the range of 6.27 (mΩ) to 6.31 (mΩ). The difference between the maximum value and the minimum value of the R value in Examples A1 to A3 is less than 0.02 mΩ, which is the difference between the maximum value and the minimum value of the R value in Examples B1 to B3. It can be seen that the amount of fluctuation in the measurement result is reduced as compared with 04 mΩ.

Further, the X value is in the range of 2.05 (mΩ) to 2.15 (mΩ) for A1 to A3, whereas the X value in the impedance measurement using the conventional zero adjustment jig is 1.8. It was in the range of (mΩ) to 2.25 (mΩ). The difference between the maximum value and the minimum value of the X value in Examples A1 to A3 is less than 0.1 mΩ, which is the difference between the maximum value and the minimum value of the X value in Examples B1 to B3. It can be seen that the amount of fluctuation in the measurement result is reduced as compared with 45 mΩ.

This shows that the measured value by the impedance measurement using the zero adjustment jig used in the zero adjustment correction method according to the present invention suppresses the measurement error and is reproducible. In other words, by using the battery cell that is the actual measurement target as it is, zero adjustment can be performed in consideration of the eddy current and magnetic flux generated due to the internal structure of the battery cell, so the offset value calculated after executing zero adjustment is also The value takes into account eddy current and magnetic flux. Therefore, in the actual measurement after executing zero adjustment, the amount of influence (error influence amount) that leads to the impedance measurement error due to the eddy current and magnetic flux generated due to the internal structure of the battery cell is canceled (cancelled). Since the error (offset) caused by electromagnetic induction and eddy current can be suppressed, the measured value becomes a value with less error. Therefore, it is possible to improve the accuracy of measuring a minute internal impedance such as a battery cell of 1 mΩ or less for EV.

(Modification example)
The first embodiment is an example in which zero adjustment is performed using a zero adjustment jig configured by using the measurement target itself, but the first embodiment is performed using the same type as the measurement target. It is also possible to carry out zero adjustment using a zero adjustment jig configured in the same connection mode as the embodiment. For example, when the measurement target is a battery cell, zero adjustment is performed using a battery cell of the same type as the battery cell, and after zero adjustment, the battery cell is replaced with the actual measurement target battery cell, and wiring (current) is performed. The measurement is performed with the state of the measurement line and voltage measurement line) the same as the state of the wiring at the time of zero adjustment. The connection loop is a cell of the battery cell 30 extending from one tab terminal of a battery cell of the same type as the battery cell (hereinafter, referred to as “same type battery cell”) to the other tab terminal located at a predetermined distance. It is formed in close proximity to the surface and along the surface of the battery cell. The same type means a shape (same standard) that is substantially the same as the shape (standard) of the measurement target.

According to this modification, since zero adjustment is first performed using the same type of measurement target, it is not necessary to perform zero adjustment each time when measuring for a plurality of measurement targets thereafter.

[Second Embodiment]
Hereinafter, a second embodiment of the zero adjustment correction method according to the present invention will be described with reference to FIG. In the zero adjustment correction method according to the first embodiment described above, the number of battery cells in which one zero adjustment jig is used is one (singular), whereas in the second embodiment, the number of battery cells is one (singular). The difference is that the number of battery cells in which one zero adjustment jig is used is multiple. In FIG. 4, the voltage measurement loop (Hi side sense line, Lo side sense line), the connection point connected to one end of the Hi side sense line, and the connection point connected to one end of the Lo side sense line are omitted for convenience. ..

In the measurement and inspection of battery cells, a dedicated tray (not shown) containing a plurality of battery cells is generally transported to a production line. A plurality of battery cells housed in this dedicated tray are arranged in the same direction. When measuring the impedance of a plurality of battery cells housed in this dedicated tray, measurement error is caused by the leakage flux due to the measurement current flowing from the constant current source of the impedance measuring device and the eddy current generated in the metal case of the adjacent battery cell. Will occur.

For example, as shown in the upper left figure of FIG. 4, five battery cells 40, 42, 44, 46, 48 (the connection points in the voltage measurement loop are 41, 43, 45, 47, 49) in the dedicated tray. ) Is accommodated, and when impedance measurement is performed on the central battery cell 44, the central battery cell 44 is affected by eddy currents generated from the metal cases of the battery cells 42 and 46 on both sides, resulting in a measurement error. It will cause it to occur. Further, when impedance measurement is performed on the battery cells 48 (or 40) arranged at both ends, as shown in the lower left figure of FIG. 4, the battery cells 48 (or 40) on both sides are adjacent to each other. It is affected by the eddy current generated from the 46 (or 42) metal case, which causes a measurement error.

On the other hand, in the second embodiment, the zero adjustment jigs according to the first embodiment are housed in a plurality of dedicated trays, and the zero adjustment jigs 50, 52, 54, 56, The zero adjustment is individually executed for each of the 58 in the same manner as in the first embodiment described above, and after the zero adjustment is executed, the connection loops 60, 62, 64, 66, and 68 are removed, respectively, and the jig is removed. The R value and X value of the impedance of each battery cell are measured with the side sense wire and the Lo side sense wire connected via the inside of the battery cells constituting each zero adjustment jig (see the right figure of FIG. 4). ). It is also possible to prepare the same number of impedance measuring devices as the number of zero adjustment jigs and measure the impedance at the same time. Further, in the case of simultaneous measurement, it is necessary to synchronize each measurement signal in order to suppress fluctuations in the amount of influence of electromagnetic induction.

According to the impedance measurement method according to the second embodiment, the effects of electromagnetic induction and eddy current are different for each battery cell among a plurality of battery cells (between a plurality of channels), and due to this, each channel has a different effect. It is possible to reduce the variation in the difference between the maximum value and the minimum value of the impedance value of the battery cell and shorten the measurement processing time.

Further, the embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

1 Impedance measuring device 10 Measuring signal source 12 Current measuring line 15 Ammeter 20 Voltmeter 22 Voltage measuring line 25, 26 Current probe 27,28 Voltage probe 29, 60, 62, 64, 66, 68 Connection loop (connection line)
30, 40, 42, 44, 46, 48, Battery cell 31, 35 Tab terminal 32, 33, 37, 38, 39 Connection point 34 Capacitor 36, 50, 52, 54, 56, 58 Zero adjustment jig

Claims (6)

The measurement target includes a measurement signal generation source that supplies a measurement signal of a predetermined frequency to a measurement target electronic component having a pair of terminals, and a voltage detection unit that measures a voltage generated between both terminals of the measurement target electronic component. This is a zero-adjustment correction method in an impedance measuring device that measures the impedance of electronic components.
One and the other of the pair of output terminals of the measurement signal generation source are connected to one terminal and the other terminal of the electronic component to be measured, respectively, to form a current path.
One terminal of the voltage detection unit is made DC-insulated from one terminal of the electronic component to be measured, and the connection line extending along the outer surface of the electronic component to be measured is used. It is connected to the other terminal of the electronic component to be measured, and the other terminal of the voltage detection unit is connected to the other terminal of the electronic component to be measured to perform zero adjustment.
A zero adjustment correction method characterized by this. The measurement target includes a measurement signal generation source that supplies a measurement signal of a predetermined frequency to a measurement target electronic component having a pair of terminals, and a voltage detection unit that measures a voltage generated between both terminals of the measurement target electronic component. This is a zero-adjustment correction method in an impedance measuring device that measures the impedance of electronic components.
One and the other of the pair of output terminals of the measurement signal generation source are connected to one terminal and the other terminal of an electronic component of the same type as the electronic component to be measured, respectively, to form a current path.
One terminal of the voltage detection unit is made DC-insulated from one terminal of the same type of electronic component, and the connection line extending along the outer surface of the same type of electronic component is used. Connect to the other terminal of the same type of electronic component, connect the other terminal of the voltage detector to the other terminal of the same type of electronic component, and perform zero adjustment.
A zero adjustment correction method characterized by this. A measurement signal source that supplies a measurement signal of a predetermined frequency to the first to Nth (N is an integer of 2 or more) measurement target electronic components each having a pair of terminals, and the first to Nth measurement target electronic components. This is a zero-adjustment correction method in an impedance measuring device that measures the impedance of each of the first to Nth measurement target electronic components, including a voltage detection unit that measures the voltage generated between each of the two terminals.
One and the other of the pair of output terminals of the measurement signal generation source are individually connected to one terminal and the other terminal of the first to Nth measurement target electronic components to form a current path.
One terminal of the voltage detection unit is electrically insulated from each one terminal of the first to Nth measurement target electronic components for each measurement of the first to Nth measurement target electronic components. In this state, it is connected to each of the other terminals of the first to Nth measurement target electronic components via a connection line extending along the outer surface of each of the first to Nth measurement target electronic components. Then, the other terminal of the voltage detection unit is connected to the other terminal of each of the first to Nth measurement target electronic components to execute zero adjustment.
A zero adjustment correction method characterized by this. A measurement signal source that supplies a measurement signal of a predetermined frequency to the first to Nth (N is an integer of 2 or more) measurement target electronic components each having a pair of terminals, and the first to Nth measurement target electronic components. 1st to Nth (N is an integer of 2 or more) voltage detectors for measuring the voltage generated between the two terminals of the above, and the impedance of each of the first to Nth measurement target electronic components. This is a zero-adjustment correction method for measuring impedance measuring devices.
One and the other of the pair of output terminals of the measurement signal generation source are individually connected to one terminal and the other terminal of the first to Nth measurement target electronic components to form a current path.
One terminal of the first to first N voltage detection units is in a state of being electrically insulated from one terminal of the first to Nth measurement target electronic components, respectively, and the first to first Nth voltages are isolated from each other. 1st to Nth voltage detection by connecting to the other terminal of the 1st to Nth measurement target electronic components via a connecting line extending along the outer surface of each of the measurement target electronic components. The other terminal of the unit is connected to the other terminal of the first to Nth measurement target electronic components, respectively, and zero adjustment is executed.
A zero adjustment correction method characterized by this. After carrying out the zero-adjustment correction method according to claim 1, a state in which the state of being DC-insulated to one terminal of the measurement target electronic component is released and the connection line is removed from the measurement target electronic component. Connect one terminal of the voltage detection unit to one terminal of the electronic component to be measured, and connect the other terminal of the voltage detection unit to the other terminal of the electronic component to be measured. To measure the impedance of
An impedance measurement method characterized by this. After carrying out the zero-adjustment correction method according to claim 2, the state of being DC-insulated to one terminal of an electronic component of the same type as the electronic component to be measured is released, and the connection line is connected to the electronic component to be measured. One terminal of the voltage detection unit is connected to one terminal of the measurement target electronic component in a state of being removed from the same type of electronic component as the component, and the other terminal of the voltage detection unit is connected to the other terminal of the measurement target electronic component. Connect to the terminal and measure the impedance of the electronic component to be measured.
An impedance measurement method characterized by this.

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